Inside the little-known group setting the corporate climate agenda

As thousands of companies trumpet their plans to cut carbon pollution, a small roundtable of sustainability consultants has emerged as the go-to arbiter of corporate climate action.

The Science Based Targets initiative, or SBTi, helps businesses develop a timetable for action to shrink their climate footprint through some combination of cutting greenhouse-gas pollution and removing carbon dioxide from the atmosphere. 

For a fee, this team of several dozen analysts and technical experts will work with companies to set and publicize targets for cutting their share of emissions, deeply and quickly enough to conform with international efforts to limit global warming to 1.5 ºC above preindustrial levels. SBTi says the goals it sets are meant to convey that the business has put in place a credible schedule for driving down or eliminating emissions, in line with “the latest climate science.” 

After years of small-scale sustainability work, SBTi is growing rapidly. It has now stamped its approval on the emissions reduction timelines of more than 2,600 companies, including Nestlé, PepsiCo, and Apple. It’s working to develop climate targets with more than 2,300 more, and hopes to help set them for some 10,000 businesses by 2025.

Governments are taking notice of its work as well. Last November, the White House proposed rules that would require large federal contractors to set SBTi-approved emissions reduction plans.  

The group has earned praise for some of its strictest policies, and for reeling the private sector into a constructive conversation about climate emissions.

But its rising influence has also attracted scrutiny and raised questions about its outsize role. The fact that a single organization is setting the standards for many of the world’s largest companies makes it essential for those climate targets to be trustworthy. A number of researchers now question whether SBTi’s corporate guidelines are adequately aggressive, equitable, and clear.

Critics say SBTi is giving companies too much latitude in how they set their targets; that it is allowing them to rely on certain dubious tools to address emissions; and that it is holding emerging companies in poor nations to the same standards as huge historic polluters. 

Several studies find that the group’s methods may overstate corporate climate progress. Bill Baue, an early technical advisor to the organization and now one of its most outspoken critics, says it has exhibited  a “persistent pattern of reckless disregard for truth and transparency” in its responses to such critiques.

The broader danger, some experts say, is that the public is getting a second-best approach to climate action as companies take elective steps while governments largely fail to pass strict emissions rules.

“The optimists say, ‘We need to use every tool in the tool kit, including this voluntary initiative,’” says Jessica Green, a political science professor at the University of Toronto who studies how the private sector regulates itself. “That isn’t wrong, but companies are patting each other on the back for climate action that isn’t sufficiently credible to deal with the climate crisis.”

Alberto Carrillo Pineda, SBTi’s chief technical officer, defends the organization’s practices, noting that the companies it works with have cut emissions faster than required. He also stresses that SBTi is working to address concerns.

“No one has really done what we’re doing until we started doing it,” he says. “And once you start doing it, you start to learn and learn more. It’s an evolving field.”

Setting standards

Under the landmark Paris climate agreement, reached in 2015, most of the world’s nations committed to keep global warming to “well below” 2 ºC, and to strive to limit it to 1.5 ºC. But they didn’t lay out the path to get there––or who would pave it.

So the same year, sustainability professionals from the World Resources Institute, the World Wildlife Fund, the Carbon Disclosure Project (now CDP), and the UN Global Compact created the SBTi. The consortium devised ways to distribute the corporate responsibility for cutting emissions and meeting temperature targets, on the basis of sector, company size, and other factors. 

Other organizations offer similar sustainability accreditation, but SBTi stands out as a one-stop shop for translating climate science into goals for firms. The UN affiliation and environmental reputation of SBTi’s founding groups also helped make it the popular choice among businesses looking to set emissions plans perceived to be scientifically sound.

“Pretty much everything you touch in private-sector governance comes back to the question of ‘What’s SBTi going to do?’” says Danny Cullenward, a carbon market expert and research fellow at the Institute for Carbon Removal Law and Policy at American University. 

Observers praise many of the organization’s standards, and particularly its refusal to use carbon offsets to meet targets. Offsets allow companies to pay others to reduce emissions or remove carbon dioxide from the atmosphere through tree planting, reforestation, or similar projects and then count the climate benefits against their own emissions. But numerous studies and investigations have found that such programs frequently inflate actual climate progress.

Others give the group credit for helping persuade a rising share of the private sector to take meaningful steps to address emissions. SBTi says companies with targets that it’s approved are typically reducing their direct emissions by 12% each year, well ahead of what the organization requires. The goal-setting has had a wider effect on the field as well, helping to ratchet up the standards of other companies and corporate standard-setting groups, observers say.

Picking pathways

The starting point for SBTi’s approach is what’s known as the world’s “carbon budget.” The UN Intergovernmental Panel on Climate Change determined that collectively, nations can only afford to emit another 500 billion metric tons of carbon dioxide over roughly the next three decades and still have a 50-50 shot at holding warming to 1.5 ºC.

SBTi allocates shares of that carbon budget to sectors and companies, which then have several choices in setting targets. Two-thirds of companies have selected the simplest method, committing to per-year emissions cuts through 2030. To be in line with 1.5 ºC targets, SBTi requires companies to plan to reduce emissions across their supply chains by at least 4.2% every year. (Some companies, like Tyson Foods, Cargill, and McDonald’s, opted for a 2 ºC goal, but SBTi has recently stopped approving plans for this looser target.)

For the most part, the private sector isn’t legally required to drive down its emissions. But firms face growing pressure from investors, customers, activists, and policymakers to show that they’re taking emissions seriously and addressing rising bottom-line risks from climate change itself. Companies that secure SBTi’s approval can assert in their boardrooms, product marketing, and investor communications that they’re doing both. 

SBTi has developed a process for measuring a company’s baseline emissions based on work by Greenhouse Gas Protocol, a similar partnership between NGOs and the private sector that sets standards for reporting emissions and then signs off on a firm’s timeline for reducing them. SBTi stresses that it doesn’t evaluate or endorse the specific strategies companies use to get to the target. However, it does exert some control over the choice of those tools, as in prohibiting the use of offsets. 

Companies can also choose to follow a sector-specific pathway, which tends to be more attractive for industries such as aviation, cement, and aluminum, which are particularly difficult to clean up with today’s technologies. In that case, SBTi assigns shares of the carbon budget to sectors and the companies within them on the basis of scientific literature, market data, and guidance from industry experts.

The maritime industry, for example, gets a total budget of 12 to 16 billion tons of carbon dioxide to emit until 2050. SBTi gives the sector more time to decarbonize than other industries because it’s expected that methods for cutting emissions from shipping, including switching to low-emission fuels like ammonia and hydrogen, will take a while to scale up. 

SBTi has also developed long-term net-zero targets, with the goal that by 2050, companies will emit only as much greenhouse gas as they can reliably and durably remove from the atmosphere. They have approved such goals for around 200 companies, including Colgate Palmolive, Etsy, and H&M. 

In 2022, SBTi approved targets set by more than 1,000 companies. Firms signing up now may have to wait in line for up to six months. Steve Suppan, a policy analyst at the Institute for Agriculture and Trade Policy, says the small size of its validating team, which grew from 11 people last year to 15 in 2023, is “the biggest single challenge that SBTi faces.”

SBTi requires companies to review their targets at least every five years, and work with the organization to recalculate them when there are major changes that affect the goals. The group is also preparing to implement ways of monitoring and verifying whether companies’ progress is on track. 

A fine line 

The process of allocating the limited carbon budget to individual companies, sectors, and regions hangs on assumptions about what the economy of the future will look like and how to fairly assign responsibility for climate action.

“That’s where these metrics and indicators depart from science and take us into the realm of values, ethics, and morality,” says Mark McElroy, director of the Center for Sustainable Organizations and an original member of the SBTi technical advisory group.

Some critics, for instance, argue that SBTi’s methods don’t adequately consider the historical responsibility for current warming or the barriers developing countries might face in cutting emissions. The concern is that entrenched companies in wealthy regions that have pumped out climate pollution for decades are largely treated the same way as emerging firms in poor countries with limited resources to alter their business practices.

For that reason, scientists have said that SBTi’s methods do not support a UN principle, established in 1992, that richer countries should bear a larger share of the responsibility for mitigating climate change.

McElroy developed one of the few methods for setting private-sector emissions targets that can incorporate such global equity considerations. It also reevaluates targets each year, forcing companies to do more to stay within their sector’s cumulative emissions budgets over time. 

Anders Bjørn, a postdoctoral fellow at the Technical University of Denmark, found in a 2021 study that SBTi’s methods for setting targets may grant companies too much slack, permitting total sector emissions to surpass what’s allowable under the 1.5 ºC temperature target. (When he tested the accuracy of a variety of such approaches, he found that McElroy’s method, which SBTi doesn’t use, does the best job of keeping companies in line with those goals.) 

Bjørn’s research has also highlighted another worry among scientists: SBTi companies may overstate their progress by relying on renewable energy credits, which have raised concerns similar to those surrounding carbon offsets. The tool allows companies to count payments to low-carbon energy projects as reductions in their own emissions. However, renewables like wind and solar power plants are becoming cheaper and benefit from government incentives, so it’s increasingly difficult to justify the credit as necessary for their development. 

“SBTi is walking a very fine and nuanced line,” Cullenward says. “In specific applications … the concept of offsetting is very much in place.”

Recent research from the NewClimate Institute and Carbon Market Watch has also highlighted the fact that SBTi allows certain sectors to use offset-like projects so long as they’re within their own operations or supply chains, a practice they refer to as “insetting.” In an earlier investigation, the same two organizations also found that companies took advantage of an SBTi policy that allows companies to select years with especially high emissions as their starting point, making it easier to achieve subsequent annual reductions.

In addition, SBTi has raised concerns about potential conflicts of interest, most conspicuously by earning money from the companies it evaluates. It charges companies for its services, with prices ranging from $1,000 to $14,500, depending on the company’s size and the complexity of its climate targets. In 2021, it also raised $36 million from the Bezos Earth Fund, the Laudes Foundation, and the IKEA Foundation. (IKEA has received approval for its near-term targets.)

Still another concern involves carbon removal. Under SBTi’s net-zero plans, companies can counterbalance up to 10% their emissions with “permanent removal” of carbon dioxide from the atmosphere. These efforts, it expects, will have negated 20 to 40 billion tons of emissions by 2050.

But SBTi hasn’t clarified how to do this carbon removal. Not all techniques for taking carbon out of the atmosphere can do it permanently, and none of the reliable and long-term options are cheap and widely available yet. Amid these concerns, a collection of research groups and businesses have asked SBTi to define “permanent” as lasting at least a thousand years and to encourage companies to invest in developing the technologies. 

SBTi’s process also leaves at least two glaring gaps. To limit warming to 1.5 ºC, every company around the world will need to cut emissions at similar annual levels. But so far, companies with approved targets and commitments to develop them account for only 3 billion tons of carbon dioxide (or other greenhouse gases with equivalent warming effects). Meanwhile, the world produces around 41 billion tons per year from energy use alone. Notably, the group also doesn’t currently approve targets for companies in the fossil-fuel sector, the source of the overwhelming majority of human-caused emissions. Even substantial emissions reductions across other sectors can only do so much to ease climate change without radical changes in the way oil and gas companies operate. 

Addressing challenges 

In response to various criticisms, SBTi says it is adjusting how it structures the organization. It has hired a compliance director to manage complaints and formed a technical council to review and approve more technical decisions.

But it has defended its methods for setting targets, saying that other approaches, including McElroy’s, rely on volatile economic measures. It adds that its approach should be judged on many different measures, and that it must balance rigorous science against “viable” implementation. In the same vein, it says companies ought to be able to choose the year to establish baseline emissions, because businesses change structure often and emissions accounting principles continually improve.

The group said in a statement that it is working to incorporate regional data to ensure that targets are more ambitious and globally fair, another subject that the technical council will consider. 

SBTi is also working with Greenhouse Gas Protocol to boost transparency and assess whether it should update policies regarding the use of renewable energy credits. “This isn’t a challenge that’s unique to the SBTi, but it’s one that it is committed to addressing,” the statement said. 

The group disagrees that any of the practices it allows amount to a form of offsets. It says that more work is needed to understand the climate benefits from insetting and that it will assess such projects on a case-by-case basis.

As for the concerns about conflicts of interest, SBTi says its fees are only meant to ensure that the organization can handle the demand for its services. Most funding, it says, comes from charitable trusts and foundations. “We have no commercial interest at all,” Pineda says. “With the entities that we assess, we have completely independent governance.” 

He stresses that methods to suck carbon out of the atmosphere represent a small part of SBTi’s approved plans. The world “cannot really rely on high-scale adoption” of carbon removal, he says. “What we need to rely on is rapid decarbonization.”

Finally, SBTi plans to release details this year about how it plans to monitor whether companies are on track to meet their targets, and what it will do if they are not.

Providing cover

By 2025, SBTi hopes to approve targets for companies worth a total $20 trillion and responsible for 5 billion tons of annual emissions. But that would still represent only a sliver of global climate pollution. And some fear that the group’s standards could slip rather than strengthen from this point, as more big companies join the fold and push against the strictest rules.

Doreen Stabinsky, a professor of global environmental politics at the College of the Atlantic, fears that “in order to try to be palatable to the corporate sector,” SBTi will relax its requirements over time. Without public access to the emissions data SBTi sees, its climate targets are “effectively inscrutable,” she and other scientists told the organization in October. (Stabinsky and Bjørn are part of SBTi’s newly created technical council.)

Others argue there’s a more fundamental problem that can’t be addressed through any technical updates. Voluntary standards may simply be incapable of pushing profit-driven companies hard enough to undertake the rapid, systemic transformations that the UN temperature targets and climate realities demand. 

In addition, the group’s formally approved targets could have the perverse effect of providing climate cover for companies, allowing them to drag their feet on making the necessary changes or even lobby against stricter rules. 

SBTi acknowledges that government action is important, calling regulation vital to encourage “slower adopters” of climate action. But notably, a number of companies with SBTi-approved targets have publicly railed against rules proposed by the US Securities and Exchange Commission to require companies to publish their emissions plans and disclose exposure to risks from climate-related impacts like floods and fires.

Tyson said climate disclosures could “chill innovation and lead to competitive harm,” and Walmart asked the commission to remove requirements to report climate-related financial information. Executives of Apple and PepsiCo are members of the Business Roundtable, which has lobbied the commission to undercut obligations to report climate risks within supply chains, according to an analysis by the Guardian.

In Green’s view the SBTi acts more like a club than a regulator, more interested in getting people to join than in changing their behavior. It’s not the only or even the best option for driving climate action, she says. It’s just the one that’s available now, while countries still lack the will to pass and enforce stringent emissions rules despite the growing dangers from climate change.

Ian Morse is an independent journalist based in Seattle who has contributed to The Washington Post, Mongabay, Undark Magazine and other outlets, and who writes the Green Rocks newsletter.

This startup says its first fusion plant is five years away. Experts doubt it.

A startup backed by Sam Altman says it’s on track to flip on the world’s first fusion power plant in five years, dramatically shortening the timeline to a carbon-free energy source that’s eluded scientists for three-quarters of a century

Helion Energy’s announcement that it’s on the verge of commercializing the process that powers the sun is an astounding claim—and a questionable one, according to several nuclear experts. That’s mainly because the company hasn’t said and won’t comment on whether it’s passed the first big test for fusion: getting more energy out of the process than it takes to drive it.

Nevertheless, the 10-year-old company, which is based in Everett, Washington, has already lined up its first customer for the planned commercial facility, striking a power purchase agreement with the software giant Microsoft. Helion expects that the plant will be built somewhere in the state of Washington, go online in 2028, and reach its full generating capacity of at least 50 megawatts within a year. 

That’s small as power plants go: the generating capacity of a typical US natural-gas plant is now well over 500 megawatts. But if Helion pulls it off, it would be a big deal: economical commercial fusion plants could deliver a steady stream of clean electricity, without the intermittency challenges of solar and wind power or the controversies and concerns associated with the technology’s nuclear cousin, fission. It could make it cheaper and easier to eliminate the greenhouse gases driving climate change from the power sector, and it would help meet soaring electricity demand as the world races to cut pollution from transportation, homes, office buildings, and industry.

Other fusion startups are aiming to begin operating power plants in the early 2030s, and plenty of observers think even those timelines are overly optimistic.

Unless Helion has made some major advances that most organizations would have trumpeted, the company still faces a series of very difficult technical tasks, says Jessica Lovering, executive director of Good Energy Collective, a policy research group that advocates for the use of nuclear energy.

That includes producing more energy than the process uses—and converting that energy into a consistent, affordable form of electricity that could flow onto the grid.

“So there are two big unproven steps,” says Lovering, adding that she is “skeptical of the technological readiness.” 

Adam Stein, director of the Nuclear Energy Innovation program at the Breakthrough Institute, also thinks that Helion still appears to face some big technical obstacles. 

“That doesn’t mean it’s impossible, but it’s also not the steady march toward victory that is often portrayed,” he says. “These are breakthroughs we’re talking about.”

Getting to gain

To date, only one research group, Lawrence Livermore’s National Ignition Facility, has achieved what’s known as “scientific net energy gain”—meaning, in that case, that it produced more energy from fusion than was delivered through the 192 lasers used to trigger the reactions. That milestone was reached late last year.

The experiment did not, however, achieve what’s known as “engineering gain,” which takes into account the total energy used to power up the lasers and otherwise drive the process. Getting to that point is essential for developing practical commercial fusion systems, experts say. (Meanwhile, the lab hasn’t managed to repeat the feat so far.)

a worker in a Helion hard hat walked down an aisle surrounded by machinery covered in plastic sheeting
A Helion engineer prepares for a pulsed power test.
HELION

In 2015, David Kirtley, the chief executive officer of Helion, told me he believed the company could achieve “scientific gain” in the next three years. When asked again this week whether the company has achieved scientific or engineering gain, or when it expects to, Helion declined to comment, citing competitiveness issues. The company said the “initial timeline projections” assumed it would be able to raise funds faster than it did.

On top of the technical challenges, Helion will also need to plan, license, and build its commercial plant even as the US Nuclear Regulatory Commission is finalizing details of how it will oversee the nascent sector.

But Kirtley stresses that the company, which employs nearly 160 people, is taking an approach that sidesteps some of the obstacles other research groups and startups face. He also says that it has already made significant advances.

Helion has developed and tested six prototypes to date. It announced in 2021 that the latest, dubbed Trenta, reached temperatures of more than 100 million ˚C, making it the first private company to publicly reveal it had achieved the temperatures necessary for a commercial plant. The company is now building a seventh, Polaris, that it expects will demonstrate the ability to produce electricity from the reactions next year.

“Given the history of fusion, we understand that there will be skepticism, and we believe that skepticism is healthy,” Helion said in a response to MIT Technology Review. 

“The results and progress of our 6th prototype give us great confidence that our timeline is realistic and that we can build the first fusion power plant by 2028,” the statement continued.

Plasma and pulses

While the fission reactions that power traditional nuclear power plants split atoms apart, fusion works by forcing them together, under extremely high  temperatures, to overcome the usual repulsive forces of atoms in close proximity. That produces a new atom minus a little bit of mass, the loss of which generates a whole lot of energy.

Most other labs and startups rely on powerful lasers or doughnut-shaped machines surrounded by powerful magnets, known as tokamaks, to create the conditions in which a sustained series of fusion reactions can occur—a condition known as ignition. But Helion is developing what it calls a “pulsed non-ignition fusion system,” which only requires fusion to take place for short periods. 

The company’s device is a six–by-40-foot barbell-shaped “plasma accelerator.” It uses powerful magnets to heat a gas mixture to the point that the atoms break apart, creating rings of an ultra-hot state of matter known as plasma on either end of the device. 

The magnets then propel those rings at each other at a million miles per hour, and further compress them in the middle of the device, which creates those temperatures of more than 100 million ˚C, the company says. That triggers fusion reactions, in which nuclei collide, protons and neutrons combine, various particles are released, and energy is produced.

Other fusion approaches would require an additional step to convert that energy into electricity, through conventional methods like warming water or other working fluids into a gas that turns a turbine. But Kirtley says Helion’s process can recover electricity directly.

As the plasma continues to heat and expand, its own magnetic fields push against those created by the magnets surrounding the device. That drives a flow of charged particles, otherwise known as an electric current, through the adjacent electromagnetic coils. And that, in turn, recharges an energy storage device known as a capacitor, which powers up the magnets, readying them to deliver the next pulse. 

To work as a power plant, Helion’s device will need to produce energy on top of what’s required for the pulses. That additional energy would be then converted into alternating current and routed onto the grid.

The planned commercial generator wouldn’t need to be physically larger than Helion’s latest prototype, but it will require additional systems for cooling, electricity connections, and other purposes, Kirtley says.

“Engineering challenges”

Paul Wilson, a professor of nuclear engineering at the University of Wisconsin Madison, says it would “surprise” him if a commercial fusion plant was up and running in 2028. But he says it “would be exciting” if it did occur.

He agrees that there are inherent advantages in Helion’s approach, but he also notes some sharp trade-offs.  

The easiest fuel choice for achieving fusion is a combination of two isotopes of hydrogen—deuterium and tritium. But Helion has swapped in helium-3 for the latter. 

That would produce fewer neutrons, a subatomic particle usually nestled in the nuclei that makes other objects radioactive, which should thus reduce damage to the device and ease downstream radioactive waste issues. But it also complicates the process for obtaining the necessary fuels and the engineering required to bring about fusion conditions, Wilson says.

Similarly, the pulsed approach, which rival startups like Zap Energy are also pursuing versions of, does eliminate the need to create sustained fusion reactions. But it also makes the up-front engineering a lot trickier.

“The challenge is to prove … whether they can create a large enough pulse to create enough energy, and then capture enough of it to fuel the next pulse,” Wilson says. “If they are able to do so, then the engineering challenges they may face for the rest of the system would be easier than what some of the other companies are trying to accomplish.”

“Super confident”

There are a few additional points in Helion’s favor, including the fact that the company has a significant war chest to fund its efforts. 

Helion has raised $570 million in venture capital to date, from investors such as Peter Thiel’s Mithril Capital, Y Combinator, Facebook cofounder Dustin Moskovitz, and LinkedIn cofounder Reid Hoffman. But the bulk of its funds came from a $500 million round announced in November 2021 that included $375 million from Sam Altman, the CEO of OpenAI—his largest single investment.

Altman previously told MIT Technology Review that he initially put about $10 million into Helion but dramatically boosted his investment as he “became super confident it is going to work.”

Helion’s seventh-generation prototype fusion generator, Polaris.
HELION

Under the deal announced on Wednesday, Microsoft will pay for electricity that Helion generates, assuming the plant is eventually built and operated. The software company didn’t respond to questions about whether there was any up-front money involved, or whether it has made any investments in Helion.

The agreement allows Helion to zero in on a location and demonstrates a market demand that could spur additional activity in commercial fusion, Kirtley says.

Brad Smith, vice chair and president at Microsoft, said in a prepared statement that the deal will support the software company’s “long-term clean energy goals” and “will advance the market to establish a new, efficient method for bringing more clean energy to the grid, faster.” 

Regulatory challenges 

Amid the increasing commercial activity, the US Nuclear Regulatory Commission recently made a key determination over how it will license fusion plants, adopting an approach used for research particle accelerators rather than the more onerous process used for fission power plants.

Fusion systems do produce nuclear waste, which necessitates careful procedures and rules for handling the materials and eventually decommissioning the plants, experts say. But the facilities don’t generate the same very long-lasting radioactive refuse that fission plants do, or present the same sorts of storage challenges, controversies, and weapons proliferation risks that go with it.

The NRC staff now will need to develop a specific “rule-making” process for licensing fusion within that approach, which could still take months to years.

But going forward, it appears that fusion projects should be approved faster than traditional nuclear plants, which can easily take a decade to license and build in the US, Stein of the Breakthrough Institute says. 

For his part, Kirtley is “confident” that Helion will be able to turn on the world’s first fusion power plant in 2028, given the progress it’s made, the NRC decision, their ongoing work with state and federal regulators, and the fact that they’ve already licensed a handful of prototypes.

But he does acknowledge that the company faces big challenges and some potential for delays.

“The truth is fusion is hard, and new power plants are hard, and first-of-a-kind anythings are also hard,” he says. “It’s one reason we’re trying to get out in front and trying to solve all those problems today.”

How chemists could give new life to old wind turbine blades

Wind turbines are crucial for addressing climate change, but when they’ve reached the end of their lives, turbine blades could add up to a lot of waste. Now new research, published in Nature, could represent a first step toward building renewable-energy infrastructure that doesn’t end up in a landfill.

Wind turbine blades need to be tough to be useful. These workhorses of renewable energy last for decades, frequently spinning around up to 30 times each minute.

But when it’s time to decommission one, a wind turbine’s strength can become a weakness.  Because the blades are designed to be so durable, the materials used to build them can’t currently be recycled. And about 43 million tons of these blades will be decommissioned by 2050.

The new work describes a way to recover the main components of wind turbine blades, breaking down the plastic that holds them together without destroying the material’s primary building blocks. 

“We need sustainable energy, but we also have to consider the waste, and we have to find solutions for that,” says Alexander Ahrens, a postdoctoral researcher at Aarhus University in Denmark and the lead author of the new study.

Wind turbine blades are made with strong plastic called epoxy resin. Because of the chemical bonds created when epoxy resin solidifies, it can’t be melted and squished into a new shape to be reused, like the plastic that makes up water bottles or milk jugs. In this case, fibers are also mixed into the resin for extra strength. This kind of reinforced material—called fiberglass when the supporting fibers are made using glass—is often used for high-intensity applications like airplane wings and boats.

“Because these materials are so durable, there’s not really right now a technology that is fit for recycling them,” Ahrens says.

Some methods do exist for breaking down fiberglass, but these approaches usually render the epoxy portion unusable and often damage the glass fibers as well. The researchers at Aarhus set out to develop a method gentle enough to let the main components be used again.

The resulting approach takes aim at chemical bonds that lock the plastic into place and “chews them up like Pac-Man—just chews up the epoxy and liberates those glass fibers,” says Troels Skrydstrup, a professor of chemistry at Aarhus and another author of the new study.

To break down the epoxy materials, researchers submerged them in a mixture of solvents and added a catalyst, which helped accelerate the chemical reaction. They heated everything up to 160 °C (320 °F) for between 16 hours and several days, until the target material was fully broken down. 

After some initial tests, the researchers used their method to chew up a one-inch-square chunk of a wind turbine blade. After six days, the result was nearly spotless glass fibers (and a supporting metal sheet that runs through most turbine blades) and vials of ingredients that could be used again in new materials. 

This is the first time that researchers have been able to break down a reinforced epoxy material to recover both the plastic’s building blocks and the glass fibers inside without damaging either, Skrydstrup says.

While this process was able to chew up materials in the lab, it could be difficult to pull off at large enough scale to make a dent in the millions of tons of wind turbines coming out of service in the next few decades. “I think what’s important is that it shows a proof of concept that may inspire others to start looking in this direction,” Skrydstrup says.

Proof-of-concept research is key in chemical recycling, and this approach is “really exciting,” especially because the researchers demonstrated that it works on real waste, says Julie Rorrer, a professor at the University of Washington who studies chemical recycling.

The next stage, Rorrer says, would be figuring out how this could work on an industrial scale, or determining what would need to be adjusted so the process could be quick and efficient enough to be economical.

One of the possible roadblocks to commercial operation is that the catalyst used in the researchers’ recycling method relies on an expensive metal called ruthenium. The researchers were using a lot of this metal, and though it doesn’t get used up during the reaction, it could be difficult to recover and use again.

There may be other methods better suited to recycling turbine blades in industry. Skrydstrup’s lab has developed another process that also breaks down turbine blades, which was referenced in a press release earlier this year by the wind turbine maker Vestas.

Skrydstrup says that approach is a two-part process and might be more feasible to run at commercial scale, though the researchers declined to give specific details because they’re working to submit the results to scientific journals.

These are just two of the many approaches being developed in advanced recycling. There’s been a huge boom in research on ways to clean up all sorts of materials, from single-use plastics to wind turbines, Rorrer says, and for good reason: “There’s valuable things in trash.”

Inside Germany’s power struggle over nuclear energy

This article is from The Spark, MIT Technology Review’s weekly climate newsletter. To receive it in your inbox every Wednesday, sign up here.

We’re gathered here today to commemorate the demise of a towering figure in the energy world: nuclear power in Germany. Born: June 16, 1961. Died: April 15, 2023. 

Just a decade ago, Germany was using nuclear power to meet about a quarter of its electricity demand, but now nuclear’s watch is ended. Earlier this month, the nation shut down the last of its nuclear power plants, 60 years after the first one began operation.

The reactions are mixed. Some consider this a victory, cheering as Germany moves away from an electricity source they see as dangerous and flawed. But others see it as a major potential roadblock for climate action—while nuclear plants have been shuttered left and right, coal power has chugged along, providing a huge chunk of the country’s electricity and spewing emissions all the while.

Germany’s true challenge is ahead, as the country tries to meet ambitious climate goals without the steady electricity supply that nuclear provides. The whole situation highlights what I see as a major question in the climate movement today: Where exactly should nuclear fit in? 

What’s been going on with nuclear power in Germany? 

There’s been a long and drawn-out battle in Germany over nuclear that’s lasted for decades. Here’s the SparkNotes version of what’s been happening: 

  • After a few incidents in the 1980s (including small ones inside Germany, not to mention Chernobyl in what’s now Ukraine), public support for nuclear power began to erode. Questions about what to do with nuclear waste started to grow as well. 
  • After lots of protests, the government made a plan to shut down all nuclear power plants. The plan was passed into law in 2002. 
  • After some flip-flopping, things came to a head again in 2011 with the Fukushima accident in Japan. German chancellor Angela Merkel pushed to speed up closures and finish the job by 2022. 
  • The shutdown was delayed from October 2022 because of concerns about energy security related to the war in Ukraine. But on April 15, 2023, at 11:59 p.m. local time, Germany’s last nuclear power plant disconnected from the electricity grid

So what does all this have to do with climate change? 

Shutting down nuclear power plants could be a big setback for climate goals. While Germany has made major progress on installing renewable energy like wind and solar, emissions from its electricity sector have been shockingly slow to fall. The country has pledged to reach net-zero emissions by 2045, but it missed its climate targets for both 2021 and 2022. To reach its 2030 targets, it may need to triple the pace of its emissions cuts

That slow progress is in part because wind and solar energy are replacing nuclear power —a low-emissions power source—instead of coal. 

Germany still burns a lot of coal compared with many other industrialized nations, and a lot of it is lignite coal that’s especially pollution intensive. Germany’s government has committed to phasing out coal by no later than 2038, with the current leadership targeting an earlier goal of 2030. Weaning off coal has been slow, however—recently some shuttered coal plants were restarted this winter because of the energy crisis. 

Looking at the difference between France and Germany, two high-income neighbors in western Europe, can illustrate why all this matters. 

On April 16, the day after the final nuclear plants shut down in Germany, the country recorded a carbon intensity of 476 grams of CO2 equivalent for every kilowatt-hour of electricity produced. About half the nation’s electricity came from renewable sources, but coal made up about 30% of the supply. 

Meanwhile, in France, only 30% of electricity came from renewables. Add in nuclear, though, and low-carbon power sources made up 93% of the electricity supply. So France’s emissions for every unit of electricity were lower than Germany’s by a factor of nearly 10, at 51 grams CO2-eq/kWh, largely because of its heavy reliance on nuclear power. 

Is nuclear energy necessary for climate action, then? 

Supporters of Germany’s nuclear phaseout say that getting rid of nuclear power doesn’t prevent the country from also ditching coal and meeting climate goals. “It’s not an either/or question: they both need to be phased out. All fossil fuels need to be phased out,” says Miranda Schreurs, chair of environmental and climate policy at the Technical University of Munich. Schreurs was part of the 2011 committee that developed the government plan to finish the nuclear shutdown. 

Schreurs argues that the speed at which Germany has deployed renewables has been spurred by the urgency to shut down nuclear plants. There are also other options to power the country with low-emissions electricity, she says. 

Building lots of transmission lines can help move power from where it’s windy or sunny to where it’s not. Energy storage technologies like green hydrogen and batteries can also help wind and solar meet most electricity demand in the country. 

Meeting climate goals on time without nuclear energy might be easier said than done, though. By the end of the decade, Germany’s electricity generation capacity could fall short by about 30 gigawatts if it shuts down coal plants as expected, according to a 2022 report from McKinsey. 

Germany’s nuclear age might be behind us. The question is whether fossil fuels can be the next to go. 

Keeping up with climate

Buses are underrated. Even if they run on gas, a good bus system can cut emissions relative to cars. (Scientific American)

A common chemical, methanol, could help clean up shipping. As with other alternative fuels, though, the devil is in the details. (Canary Media)

→ In China, methanol-powered cars are hitting the streets. (MIT Technology Review)

If you’re taking off on summer travel soon, you might want to think twice before ticking the box to buy carbon offsets for your flight. Experts say many of these programs are basically meaningless. (Washington Post)

The Colorado River is going to the cows. New estimates suggest that about 80% of the water used from the river goes to irrigation, and a lot of the crops are used to feed cows. (Vox)

China’s largest EV company is out on self-driving cars. A spokesperson for BYD told reporters at the Shanghai auto show that the company sees the tech as “basically impossible.” (CNBC)

The US Environmental Protection Agency will soon be announcing big new rules to cut carbon pollution from power plants. The regulations could push plants to use carbon capture, a relatively unproven technology. (New York Times)

→ The new rules are likely to wind up in front of the Supreme Court, though. (E&E News)

→ The court gutted the EPA’s ability to regulate power plant emissions in a 2022 decision. (MIT Technology Review)

Tesla’s side hustle might eventually be its cash cow. While the company is mostly known for its vehicles, growth of its stationary storage and solar business together rose by over 350% in the first three months of 2023. (Canary Media)

They might be roughly 7,000 miles apart, but the fates of Galveston, Texas, and the Thwaites Glacier in Antarctica are intimately connected. Take a look at why. (NPR)

→ Some researchers are considering drastic interventions to save the “doomsday” glacier. (MIT Technology Review)

Zapping seawater with electricity could help pull carbon dioxide out of the air. But there are a lot of unknowns around this and other methods of marine carbon removal. (Associated Press)

Inside the conference where researchers are solving the clean-energy puzzle

This article is from The Spark, MIT Technology Review’s weekly climate newsletter. To receive it in your inbox every Wednesday, sign up here.

I spent last week in Washington, DC, and when I wasn’t fawning over the cherry blossoms, I was soaking up all the newest and wildest ideas in energy. 

The Advanced Research Projects Agency for Energy (ARPA-E) funds high-risk, high-reward energy research projects, and each year the agency hosts a summit where funding recipients and other researchers and companies in energy can gather to talk about what’s new in the field.

As I listened to presentations, met with researchers, and—especially—wandered around the showcase, I often had a vague feeling of whiplash. Standing at one booth trying to wrap my head around how we might measure carbon stored by plants, I would look over and see another group focused on making nuclear fusion a more practical way to power the world. 

There are plenty of tried-and-true solutions that can begin to address climate change right now: wind and solar power are being deployed at massive scales, electric vehicles are coming to the mainstream, and new technologies are helping companies make even fossil-fuel production less polluting. But as we knock out the easy wins, we’ll also need to get creative to tackle harder-to-solve sectors and reach net-zero emissions. Here are a few intriguing projects from the ARPA-E showcase that caught my eye.

Vaporized rocks

“I heard you have rocks here!” I exclaimed as I approached the Quaise Energy station. 

Quaise’s booth featured a screen flashing through some fast facts and demonstration videos. And sure enough, laid out on the table were two slabs of rock. They looked a bit worse for wear, each sporting a hole about the size of a quarter in the middle, singed around the edges. 

These rocks earned their scorch marks in service of a big goal: making geothermal power possible anywhere. Today, the high temperatures needed to generate electricity using heat from the Earth are only accessible close to the surface in certain places on the planet, like Iceland or the western US. 

Geothermal power could in theory be deployed anywhere, if we could drill deep enough. Getting there won’t be easy, though, and could require drilling 20 kilometers (12 miles) beneath the surface. That’s deeper than any oil and gas drilling done today. 

Rather than grinding through layers of granite with conventional drilling technology, Quaise plans to get through the more obstinate parts of the Earth’s crust by using high-powered millimeter waves to vaporize rock. (It’s sort of like lasers, but not quite.)

The holey samples at the company’s booth were the results of those tests. One was basalt, the other a column of granite: two common types of rock the company will have to tackle to reach the prize heat hidden underground.

Quaise has been testing its drilling technology in labs, starting with shallow depths and slowly working toward deeper and deeper holes. The plan is to start outdoor field trials later this year in Texas.

Slabs of fungus

Usually fungus would probably be one of the last things you’d want in your walls, but some researchers think it could help insulate buildings in remote areas. 

Around a quarter of all energy worldwide is used to either heat or cool homes and commercial buildings. Boosting insulation could help cut power demand and keep people comfortable as temperature swings get more dramatic with climate change. But insulation materials, which range from plastics like polystyrene and fiberglass to cotton and recycled paper, can be expensive. And in remote areas, costs can balloon with shipping distances.

Some researchers at the National Renewable Energy Laboratory are working to bring natural insulation materials to remote areas like Alaska. By mixing cellulose pulp from local trees with mycelium (the rootlike structures of fungus), they hope to perfect a locally made solution and avoid shipping polystyrene boards across the world. 

The project is a newer one, having just received ARPA-E funding this year. The team members are working to develop a mobile process to make the insulation, and they are also trying to boost the material’s insulative capacity and make sure it’s fire resistant. 

A hybrid-electric plane

Okay, they didn’t have the actual plane in the exhibition hall, but even a model plane is enough to stop me in my tracks, especially when it’s paired with test flight footage featuring the real thing. 

Ampaire is a California-based startup, and earlier this year the company completed a test flight of its Eco Caravan, a plug-in hybrid plane. By adding just a small battery, the company says, it can cut fuel consumption by 50 to 70% compared with conventional planes. 

I’m really interested in this approach, especially because it could solve a regulatory quirk that’s one of the reasons electric flight is so challenging. 

Batteries are much heavier than jet fuel is, and current battery technology means that small planes could carry a few passengers a few hundred miles. But their theoretical range gets eaten up by something called reserve requirements. Basically, according to regulators, a plane needs to have enough fuel on board for emergencies. If there’s an issue, it needs to be able to circle for a while, or even make it to a nearby airport to land. Safety, et cetera. So while a 19-seat electric plane in theory might be able to fly 160 miles, factoring in reserve requirements means the usable range might actually be more like 30 miles—a long bike ride. 

By carrying reserve requirements in jet fuel and having only enough battery power for the planned flight, a hybrid-electric plane would get a lot of bang for its buck. Ampaire hopes to get certification for its system next year. 

Keeping up with climate

If your spring sniffles have started already, you can probably thank climate change. Warm winters are causing earlier pollen production and longer allergy seasons. (Bloomberg)

A 2021 study found that fewer than 30% of electric vehicles are purchased by women. Unreliable charging stations and high prices, barriers for EV adoption in general, could be contributing to the gender gap. (The 19th)

→ Here’s why EVs are finally hitting the mainstream. (MIT Technology Review)

An invasive vine called kudzu blankets the southern US. Now, warming weather is clearing the way for the plant’s journey north. (NJ Spotlight News)

New rules for batteries in electric bikes and scooters in New York City could help make the low-emission vehicles safer. (Canary Media)

Cryptocurrency might not be the center of attention anymore, but the industry is still a climate problem. Bitcoin mining alone could continue releasing about 62 megatons of carbon dioxide into the atmosphere each year. (The Atlantic

Renewable electricity beat out coal in the US for the first time last year. Wind, solar, hydro, biomass, and geothermal together made up just over 20% of total generation. (Associated Press)

Sea otters, gray wolves, and other animals could be important allies in addressing climate change. A new study found healthy populations of certain species could be key to helping capture carbon in ecosystems. (Grist)

Efforts to use geothermal power for electricity in Japan have been slowed by the nation’s “surprisingly powerful” hot-spring owners. (New York Times)

These companies want to go beyond batteries to store energy

This article is from The Spark, MIT Technology Review’s weekly climate newsletter. To receive it in your inbox every Wednesday, sign up here.

If y’all have been around for a while, you know that I love writing about batteries (see exhibits A, B, and C). Using chemical reactions to store energy is handy and scaleable, and there are about a million ways to do it, which is why batteries have basically become synonymous with energy storage. 

But more groups are starting to think outside the battery. In an effort to cut costs and store lots of energy for long periods of time, researchers and companies alike are getting creative: pumping water into the earth, compressing gas in underground caverns or massive tanks, even lifting giant blocks. 

As we build more renewable energy capacity in the form of variable sources like wind and solar power, we’re going to need to add a lot more energy storage to the grid to keep it stable and ensure there’s a way to get electricity to the people who need it. Some of that energy storage might look a little different from the batteries we usually talk about around here, so let’s take a closer look at why battery alternatives are popping up, and what it might take to make them a reality. 

A certain gravitas

As you may remember from high school physics class, energy can be stored in the form of potential energy: lift up a book, and there’s energy stored in it that’s released when you let go and gravity pulls it down. (That falling is kinetic energy in action.) 

This simple concept, in the form of pumped-storage hydropower, is the foundation of 90% of global grid storage today. That’s right—the vast majority of the world’s energy storage comes from moving water uphill. 

In a pumped hydro plant, extra electricity is used to force water uphill from one reservoir to another. Later on, just open up the gates and let gravity do its thing: water flows downhill through a turbine, generating electricity. It’s a cheap, relatively straightforward way to store energy for later. 

It’s tough to scale pumped hydro, though, since it requires specific geographic conditions (not to mention that disrupting natural water systems can be really destructive for ecosystems). 

Some groups want to reimagine energy storage, harnessing gravity without relying on water. EnergyVault is building facilities with elevators that raise and lower gigantic bricks to store energy. Gravitricity wants to lift huge weights underground, maybe in old mine shafts. 

These systems might have high efficiency, returning a lot of the energy that’s put into them. They may also last a long time, so it could be economical to store energy for days, weeks, or maybe even months. 

Proponents say gravity-based systems could help meet demand for long-duration storage. But there’s also skepticism about the future of the approach, since they’ll require a lot of work to build, and they might be tougher to maintain than expected. EnergyVault is making progress on a planned facility in China, though the company has also been deploying a lot of lithium-ion battery installations these days.

The big squeeze

Let’s go back to high school physics one more time for another concept: pressure. If you squeeze something into a smaller space, you’re raising the pressure.

Turning that pressure into usable energy is the idea behind compressed-air energy storage. All you need is an underground salt cavern. When you’ve got electricity you need to use, you can run pumps to push air inside the cavern. Then, when you need to get energy out, just release a valve and let the escaping air spin a turbine to generate electricity again. 

There are only a couple of these facilities running worldwide, one in Germany and another in Alabama. In the past, they’ve been tied up with fossil fuels, since they usually work alongside natural-gas power plants. But now companies want to reimagine compressed-air storage, using it for renewables and expanding where it can be used. 

Earlier this year, local governments in California signed contracts with Hydrostor, which is building what would be the world’s largest compressed-air storage facility. Instead of relying on natural geological conditions, Hydrostor will drill three shafts deep into the earth to store the compressed air. 

It’s a billion-dollar project, and it could be operating as soon as 2028 to store energy and help smooth out California’s grid using nothing but air. 

Other groups want to take a different approach to the same concept. Energy Dome, an Italian startup, wants to compress carbon dioxide instead of air to store energy. This wouldn’t require large underground storage caverns at all—for more on the details here, check out my story from last year on Energy Dome.

Earth to battery

Some groups are also looking to pair these new approaches to energy storage with efforts to generate electricity, making new power plants more flexible. 

Take geothermal energy, which harnesses heat from inside the earth. Geothermal power plants are usually used for what’s called baseload energy, running at about the same capacity all the time. 

Now, though, a startup called Fervo Energy has shown that it can store energy using its geothermal wells. By pumping water into them, it can increase the pressure underground over time—and when that pressure is released, the geothermal plant produces more energy than usual. 

It’s a fascinating twist on energy storage and could transform what geothermal plants are capable of in the future. My colleague James Temple got to visit Fervo’s test site and published a story about the startup’s efforts earlier this week. Give it a read to get all the details.

Evelyn N. Wang in her MIT lab

BRYCE VICKMARK

Another thing

You might not be familiar with ARPA-E, but the government agency is helping shape the future of energy. Part of the DOE, ARPA-E supports high-risk, high-reward energy technologies. I sat down with its new director, Evelyn Wang, to talk about what technologies could transform energy in the future. Check out my story from Monday for more. 

Keeping up with climate

The United Nations reached a major agreement to protect ocean biodiversity. If it’s ratified, the treaty will create a group to govern the high seas. (New York Times

Do you really need that bigger EV battery? Researchers followed around hundreds of drivers for a year in the US and found that nearly 40% of drivers could make ALL their trips in a small electric vehicle with just 143 miles of range. (Inside Climate News)

One of the new Plant Vogtle nuclear reactors in Georgia just reached self-sustaining nuclear fission. The project has been plagued by delays and cost increases. (Associated Press

The way we eat is really rough on the climate—the food sector could cause nearly 1 °C of warming by 2100. Addressing meat consumption and food waste could help. (The Verge

→ Some companies want to use food waste for energy, which could help cut harmful greenhouse-gas emissions. (MIT Technology Review)

There’s a divide in the US … in how we heat our homes. It could have an impact on decarbonization, because replacing oil in Maine will present different challenges than replacing natural gas through the Midwest and Northeast. (Washington Post)

Construction began last week on a controversial lithium mine in Nevada. Environmental groups and Indigenous tribes in the area have opposed the project, arguing that the land has cultural and religious importance and the work could cause ecological harm. (Grist)

→ For the newsletter, I took a look at three myths about mining and renewable energy. (MIT Technology Review)

These companies want to tackle food waste with microbes

Some people might look in a grocery store’s dumpster and see garbage. But others are starting to see dollar signs. 

New facilities are popping up in the US to help tackle food waste using a process called anaerobic digestion, which uses microbes to break down organic materials. Divert, a company working to address food waste, announced today that it’s received a $1 billion funding agreement to help build and deploy this technology.

Divert’s new agreement with the energy infrastructure company Enbridge will help the company build and deploy new facilities across the US. If all goes according to plan, Divert could manage a total of 5% of food waste in the US by the end of the decade, says CEO and cofounder Ryan Begin.

About 60 million metric tons of food waste is generated just in the US each year, amounting to about 30% of the total food supply, according to the US Department of Agriculture. The global total is close to 1 billion metric tons. Today, that wasted food typically goes on to landfills, where it decays and produces methane, a powerful greenhouse gas. Many landfills have systems in place to capture the gases produced, but they may capture only around 60% of the methane emitted.

“We need to handle this waste somehow,” says Meltem Urgun Demirtas, head of the bioprocesses and reactive separations group at Argonne National Laboratory. In addition to helping prevent methane emissions, processing food waste the right way can even generate energy and products like fertilizers.

One option, called anaerobic digestion, is widely used today in wastewater treatment plants around the world. Now more places are using it to handle other waste, like manure on farms and discarded food. Germany leads the world in anaerobic digesters: the country runs about 10,000 such reactors today. In the US there are just over 2,000, and only a few hundred are used for food waste. 

Here’s how it works. When companies get food waste from grocery stores or food distributors, they basically liquefy it, turning it into a “trashy slurry,” Begin says. The rubber bands, stickers, and plastic packaging are removed, and the slurry is then shepherded through the rest of the process. The star of the show is the community of microbes seeded into the reactor, a bit like a sourdough starter. They gobble up the food waste and transform the watery mixture into the final products: biogas and a solid material called digestate, which can be added to soil. 

“We really are microbe farmers,” says Shawn Kreloff, CEO at Bioenergy DevCo, a company that builds and operates anaerobic digesters. Keeping the microbes happy means making sure the conditions are just right, within tight ranges of temperature and acidity. They also don’t like their food to be too salty, says Christine McKiernan, chief engineering and construction officer at Bioenergy DevCo.

Composting might be a more familiar process for dealing with food waste—it also employs microbes, and it also produces a solid material that’s packed with nutrients. The big difference is that composting happens in the presence of oxygen, so microbes break down the waste into dirt while emitting mostly carbon dioxide.

If a compost pile doesn’t get mixed enough, its microbes will be deprived of oxygen. It will naturally start going through anaerobic activity, forming methane: bad news for composting facilities that are often open to the atmosphere. Over short time spans, methane is about 80 times more powerful as a greenhouse gas than carbon dioxide.

“We need to handle this waste somehow.”

Meltem Urgun Demirtas

For companies interested in anaerobic digestion, however, producing methane is the goal. Because these facilities are sealed up, the mixture of methane and carbon dioxide produced by microbes, called biogas, can be captured and purified into biomethane, which can be used as a replacement for natural gas.

Some producers use this biomethane (also called renewable natural gas) or the unpurified biogas on-site, burning it to power their facilities. Others sell it to utilities, so it’s injected into existing natural-gas pipelines and used to generate electricity in power plants, or used in homes for heating or cooking. 

On the whole, anaerobic digestion could provide a climate benefit, but exactly how much the process reduces emissions will depend a lot on the details, says Troy Hawkins, a researcher at Argonne National Laboratory who studies the environmental effects of energy systems.

boxes of food waste in the Divert facility in Freetown, MA

BEN GEBO/DIVERT

Divert works with over 5,000 retail stores across the US to gather food waste and process it using anaerobic digestion. The company currently operates 10 digester sites in the US and uses tracking systems to help understand why certain food ends up getting wasted in the first place, Begin adds.

Deploying anaerobic digesters isn’t cheap: a full-size facility can cost tens or hundreds of millions of dollars. Designing new facilities can also take time, because most are customized for particular processing tasks. An on-site facility for an ice cream factory might look different from one that can accept everything from grocery store waste like expired frozen pizzas and old apples to used cooking oils from restaurants, McKiernan says. 

Over 11,000 additional sites in the US are ripe for deploying anaerobic digesters, from wastewater facilities to food waste sites, according to a 2014 report from US federal agencies. If all those facilities were built, they could generate enough energy to power 3 million homes. The American Biogas Council, an industry trade group, puts the number at 15,000 sites, which would require about $45 billion to build altogether.

It won’t be cheap and it won’t be quick, but anaerobic digesters could be a significant destination for food waste in the future, helping to turn one person’s table scraps into another person’s energy.

Correction: An earlier version of this article misattributed a quote from Shawn Kreloff.

When hydrogen will help climate change—and when it won’t. 

Have you ever heard of the hydrogen rainbow?

While hydrogen gas is colorless, the industry sometimes uses colors as shorthand to describe which of the many possible processes was used to make a particular batch. There’s gray, green, and blue hydrogen, along with more vibrant tones like pink—a whole rainbow (kind of).

Hydrogen is often heralded as a climate hero because when it’s used as a fuel in things like buses or steel production, there are no direct carbon emissions (or related warming) to worry about. As the world tries to cut down on our use of fossil fuels, there could be plenty of new demand for this carbon-free energy source.

But how hydrogen is made could determine just how helpful it is for the climate. That’s where the rainbow comes in. (I’ve added an at-a-glance table below so you can untangle all these colors.) 

Last week, the European Commission released rules that define what “renewable” hydrogen is: in other words, what it means for hydrogen to be green. There was also a fascinating story in Science last week about naturally occurring, or gold, hydrogen. 

So let’s dive into the hydrogen rainbow and explore where this fuel of the future might come from. 

What do we need hydrogen for?

We already use a lot of hydrogen today: global demand was 94 million metric tons (Mt) in 2021. Most of that was used for oil refining, as well as production of ammonia (for fertilizer) and methanol (for chemical manufacturing). 

That is likely to change in the future, because it’s also a good replacement for fossil fuels in transportation, heavy industry, and other sectors. If countries keep their climate pledges, hydrogen demand could reach 130 Mt by 2030, and about a quarter of that would be for new uses. 

The problem is, making hydrogen today overwhelmingly requires fossil fuels, usually natural gas. In so-called “gray” hydrogen production, natural gas reacts with water, generating hydrogen gas and giving off carbon emissions. 

It doesn’t have to be that way, though. For one thing, we could try to capture the carbon emissions from fossil-powered hydrogen production (this method yields so-called blue hydrogen). This is a pretty controversial approach, because carbon capture is expensive and doesn’t always work efficiently. 

Alternatively, we could rethink the process altogether and start using electricity to make hydrogen instead. This process uses an electrolyzer: water and electricity go in; hydrogen and oxygen come out. If the electricity powering that reaction comes from renewable sources, hydrogen officially earns the distinction of being “green.” 

What does it mean to be green? 

That’s the question the European Commission is trying to answer with its new rules released last week. The goal is to lay out which hydrogen projects will count for climate goals and be eligible for special funding. (That funding is important because green hydrogen is significantly more expensive than fossil-derived gray hydrogen today.) 

There are two big pieces to these new rules. First, green hydrogen will need to be produced using renewable electricity. Producers will have to either hook up directly to solar and wind farms or get electricity from the grid and sign contracts with renewable electricity generators. 

There’s a lot of renewable electricity in play here. As part of its plan to cut emissions and dependence on Russian fossil fuels, the EU is trying to reach 10 million metric tons of domestic hydrogen production annually by 2030, along with 10 million more in imports. 

Reaching that domestic production goal will require 500 TWh of renewable electricity. That’s nearly 15% of total EU electricity consumption. 

Because there’s so much electricity needed to meet hydrogen demand, regulators are trying to avoid a scenario where hydrogen production just sucks up all the existing renewable capacity. 

To combat this, the commission will require hydrogen producers to adhere to a principle called additionality. Basically, hydrogen producers should be adding new renewables to the grid, not hogging old ones. So new requirements say that hydrogen producers must use renewable energy projects built recently (within the last three years).

The rules still need to be approved, which could take a few months. In the US, similar rules regarding tax credits for hydrogen in the Inflation Reduction Act are currently being developed by the Biden administration, so we should know more soon about what green means for that market.

What if hydrogen grew on trees?

Okay, not trees exactly, but what about underground? This story, published last week in Science, digs into the possibility of naturally occurring hydrogen. 

Hydrogen isn’t something that’s considered to be widespread in nature (look at all those intense ways we’ve come up with to make it!). But some researchers are starting to change their minds about just how plentiful it might be. 

A few exploratory wells have turned up pretty clear streams of hydrogen, and now people are starting to search for reserves across Australia, Africa, and Europe. As for why we hadn’t found it before, hydrogen wouldn’t occur in the same places as oil and gas, and not many people would have gone looking for it in the past. (Natural hydrogen is sometimes given the color “gold,” by the way.)

The wild thing is, this hydrogen might actually be a renewable resource. That’s because reactions that make it may occur naturally underground when water reacts with rocks. It could be pretty inexpensive to extract, too. There are a lot of questions left before we give up our electrolyzers, but it’s really interesting to see the hydrogen rainbow add yet another color. 

If you’ve had trouble keeping all these colors straight, you’re not alone. At the end of the day, the most important thing to know isn’t what nickname is assigned to a particular hydrogen source, but what the resulting emissions are. But if you want a rainbow reference, here’s a chart! 

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Note that this isn’t a complete list, and there may be alternative definitions for some colors. 

Green hydrogen was one of our 10 Breakthrough Technologies in 2021check out this feature for more on what’s at stake and what it will take to make it a reality. 

FORD MOTOR COMPANY

Another thing

New batteries are coming to the US. Ford announced last week that it plans to build a factory in Michigan that will produce a type of lithium-ion battery made mostly in China today. These batteries could unlock cheaper, longer-lasting electric vehicles in North America. Read my story for more on the technology and what’s next for this factory. 

There have been a lot of shifting dynamics around this facility, though, and some remaining uncertainty, because Ford plans to license technology from Chinese battery giant CATL to build the batteries. In his newsletter this week, my colleague Zeyi Yang dove into why batteries have gotten so politicized recently. 

Zeyi also published a story this week about how China set up its EV industry for success, which I highly recommend. 

Keeping up with climate

The war in Ukraine began one year ago this week. Since then, it has transformed Europe’s energy landscape, speeding progress in renewables as countries have worked to cut their dependence on Russian fossil fuels. (Bloomberg)

Just how good is that electric truck for the planet? Depends on what you’re comparing it to. I liked the visualizations in this piece showing the spread of emissions from different vehicle models. (New York Times)

→ Read last week’s newsletter for more on massive EVs. (MIT Technology Review)

The “15-minute city” is an urban planning idea centered around dense communities, which can help cut emissions and make life a little bit more enjoyable (who wouldn’t mind a shorter commute?). But the concept has morphed into a conspiracy theory online. (Wired)

Tesla will open up some of its chargers in the US to all EV drivers. The move comes after a lot of campaigning from the Biden administration. (Washington Post)

→ I talked about this and other science news stories on Science Friday last week! Check out the segment for more. (Science Friday)

Cryptocurrency miners are trying to remake their image to appear more climate-friendly. Environmental groups and researchers are rightly skeptical. (Grist)

United Airlines is pouring money into new fuels, launching a $100 million fund this week to invest in new and existing “sustainable aviation fuel” projects. (Canary Media)

→ This isn’t the airline’s first rodeo in this space: last year I wrote about one of its investments, a company making fuel with microbes. (MIT Technology Review)

Production of nickel, a metal used in EV batteries, doubled between 2020 and 2022 in Indonesia. The city of Labota is paying the price with pollution and dangerous conditions for workers. (Wired)

We were promised smaller nuclear reactors. Where are they?

For over a decade, we’ve heard that small reactors could be a big part of nuclear power’s future.

Because of their size, small modular reactors (SMRs) could solve some of the major challenges of traditional nuclear power, making plants quicker and cheaper to build and safer to operate.  

That future may have just gotten a little closer. In the past month, Oregon-based NuScale has reached several major milestones for its planned SMRs, most recently receiving a final approval from the US federal government for its reactor design. Other companies, including Kairos Power and GE Hitachi Nuclear Energy, are also pursuing commercial SMRs, but NuScale’s reactor is the first to reach this stage, clearing one of the final regulatory hurdles before the company can build its reactors in the US. 

SMRs like NuScale’s planned reactors could provide power when and where it’s needed in easy-to-build, easy-to-manage plants. The technology could help curb climate change by replacing plants powered by fossil fuels, including coal.

But even as SMRs promise to speed up construction timelines for nuclear power, the path to this point has been full of delays and cost hikes. And the road ahead for NuScale still stretches years into the future, revealing just how much streamlining there still is to go before this form of nuclear power could be built quickly and efficiently.

Going smaller

NuScale’s SMR generates electricity by a process similar to the one used in today’s nuclear plants: the reactor splits atoms in a pressurized core, giving off heat. That heat can be used to turn water into steam that powers a turbine, generating electricity. The biggest difference is the size of the reactors.

In the past, nuclear plants have been gigantic undertakings—so-called megaprojects, costing billions of dollars. “If it’s over a billion dollars, the wheels tend to fall off on a project,” says Patrick White, a project manager at the Nuclear Innovation Alliance, a nuclear-focused think tank.

For example, construction is currently underway in Georgia to install two additional units at the existing Vogtle power plant. Each of the two planned units will have a capacity of over 1,000 megawatts, enough to power over a million homes. The reactors were supposed to start up in 2017. They still haven’t, and the project’s total cost has doubled, to over $30 billion, since construction began a decade ago.

By contrast, NuScale plans to build reactor modules that have a capacity of less than 100 megawatts. When these modules are combined in power plants, they’ll add up to a few hundred megawatts, smaller than even a single unit in the Vogtle plant. SMR plants with a capacity of a few hundred megawatts would power several hundred thousand homes—similar to an average-size coal-fired power plant in the US. 

And while the Vogtle plant sits on a site that covers more than 3,000 acres, NuScale’s SMR project should require about 65 acres of land. 

Smaller nuclear power facilities could be easier to build and might help cut costs as companies standardize designs for reactors. “That’s the benefit—it becomes more of a routine, more of a cookie-cutter project,” says Jacopo Buongiorno, director of the Center for Advanced Nuclear Energy Systems at MIT.

These reactors might also be safer, since the systems needed to keep them cool, as well as those needed to shut them down in an emergency, could be simpler. 

Untangling the red tape

The problem with all these potential benefits is that so far, they’re still mostly potential. Demonstration projects have started up in some parts of the world, with China being the first to connect an SMR to the electrical grid in 2021. Last month, GE Hitachi Nuclear Energy signed commercial contracts for a plant in Ontario, which could come online in the mid-2030s. NuScale, too, is pursuing projects in Romania and Poland. 

There are no SMRs running in the US yet, partly because of the lengthy regulatory process run by the Nuclear Regulatory Commission (NRC), an independent federal agency.

Nuclear is the only power source to have its own dedicated regulatory agency in the US. That extra oversight means no detail goes unnoticed, and it can take a while to get nuclear projects moving. “These are big, complicated projects,” says Kathryn Huff, assistant secretary in the office of nuclear energy at the US Department of Energy. The DOE helps fund SMR projects and support research, but it doesn’t oversee nuclear regulations.

NuScale started working toward regulatory approval in 2008 and submitted its official application to the NRC in 2016. In 2020, when it received a design approval for its reactor, the company said the regulatory process had cost half a billion dollars, and that it had provided about 2 million pages of supporting documents to the NRC.

After more than two years of finalizing details and a vote by the agency, the NRC released its final ruling on NuScale’s reactor design last month. The final ruling goes into effect on February 21 and certifies a NuScale design for a reactor module that generates 50 MW of electricity.

Receiving a final ruling for the design means that NuScale would only have to get approval for a reactor site and complete final safety reviews before beginning construction. So in theory, NuScale has already cleared the hardest regulatory steps required before building a reactor.

“It is a big deal and should be celebrated as a milestone,” Buongiorno says. However, he says, minimizing what’s still to come would be a mistake: “Nothing is easy and nothing is quick when it comes to the NRC.”

There’s an additional wrinkle: NuScale wants to tweak its reactor modules. While the company was going through the lengthy regulatory process, researchers were still working on reactor design. During the process of submission and planning, the company discovered that its reactors could achieve better performance.

“We found that we could actually produce more power with the same reactor, the same exact size,” says Jose Reyes, cofounder and chief technology officer at NuScale. Instead of 50 MW, the company found that each module could produce 77 MW. 

So the company changed course. For its first power plant, which will be built at the Idaho National Laboratory, NuScale is planning to package six of the higher-capacity reactors together, making the plant capacity 462 MW in total.

The upgraded power rating requires some adjustments, but the module design is fundamentally the same. Still, it means that the company needed to resubmit updated plans to the NRC, which it did last month. It could take up to two years before the altered plans are approved by the agency and the company can move on to site approval, Reyes says.

The long road ahead

Back in 2017, NuScale planned to have its first power plant in Idaho running and generating electricity for the grid by 2026. That timeline has been pushed back to 2029. 

Meanwhile, costs are higher than when the regulatory process first kicked off. In January, NuScale announced that its planned price of electricity from the Idaho plant project had increased, from $58 per megawatt-hour to $89. That’s more expensive than most other sources of electricity today, including solar and wind power and most natural-gas plants. 

The price hikes would be even higher if not for substantial federal investment. The Department of Energy has already pitched in over $1 billion to the project, and the Inflation Reduction Act passed last year includes $30/MWh in credits for nuclear power plants.

Costs have gone up for many large construction projects, as inflation has affected the price of steel and other building materials while interest rates have risen. But the increases also illustrate what often happens with first-of-their-kind engineering projects, Buongiorno says: companies may try to promise quick results and cheap power, but “these initial units will always be a little bit behind schedule and a little bit above budget.”

If price hikes continue, there’s a chance that participants could back out of NuScale’s project, which could spell danger. For SMRs in the works, “I’m not going to believe it’s for real until I see them operating,” Buongiorno says. 

The true promise of SMRs will be realized only when it’s time to build the second, the third, the fifth, and the hundredth reactor, DOE’s Huff says, and both companies and regulators are learning how to speed up the process to get there. But the benefits of SMRs are all theoretical until reactors are running, supplying electricity without the need for fossil fuels.

“It becomes truly real when electrons go on the grid,” Huff says.

Busting three myths about materials and renewable energy

This article is from The Spark, MIT Technology Review’s weekly climate newsletter. To receive it in your inbox every Wednesday, sign up here.

No piece of media shaped me more than the mid-2000s TV show MythBusters

In the show, a band of special-effects pros tested out myths from TV shows or popular knowledge, like: Can a snowplow flip a car over? Can you fly using fireworks? Are elephants really afraid of mice? The team tried to figure out the answers in a process that often involved explosions and frequently enlisted the help of a crash test dummy they called Buster. 

My process today as a journalist looks a little different, but I think dozens of rounds of the MythBusters cycle—ask, search, answer—definitely left an impression on me.

The MythBusters pilot came out 20 years ago last week, so in honor of the occasion, we’re going to be busting some myths on one of my favorite topics: the materials we need to fight climate change. 

Myth #1: We don’t have enough materials to build what we need to fight climate change. 

This one comes up a lot, and there’s a pretty good reason. We’re going to need a lot of stuff to set up a new, zero-emissions world. 

To keep things relatively simple, I’m going to focus on the two industries with the highest emissions today: electricity generation and transportation. Together, they make up nearly three-quarters of the world’s greenhouse-gas emissions. 

In order to cut emissions in these sectors, we need to build a lot of new infrastructure, especially new ways of generating electricity and batteries that can store it. So how much material are we looking at here?

Pretty much any construction requires some combination of steel, aluminum, and probably copper. According to a new study, in order to meet climate goals we’ll need a lot of each of those just to build infrastructure to generate electricity. Between now and 2050, demand could total up to 1.96 billion metric tons of steel, 241 million metric tons of aluminum, and 82 million metric tons of copper. 

That sounds like a lot, and it is. But if you compare those numbers with the known reserves on the planet that we can access economically, it’s a small fraction. And annual production won’t have to grow by more than 20% for supply of any of these materials to meet demand. 

It’s a slightly different story when it comes to more specialty ingredients, like the rare-earth metals in wind turbine engines, the polysilicon in solar panels, or the cobalt and lithium in batteries. 

For some of those materials, we’ll need growth to be more dramatic. Demand for dysprosium and neodymium could quadruple between now and 2050 because of wind turbines. We’ll probably need to double the polysilicon we make. Battery materials, too, could see demand spike. 

Getting the mines and infrastructure in place to actually meet demand will be a challenge, for sure. But in every case, the planet has plenty of reserves of the materials we need. For more on this topic and details from the study I mentioned, you can check out my story on the topic.

Myth #2: All that mining will be worse for the climate and environment than fossil fuels. 

Again, there’s a good reason that this comes up: mining has social and environmental ramifications. But let’s compare the environmental impacts of burning fossil fuels and mining renewable-energy materials.  

It can be tough to weigh different technologies that will cause different harms in different places. So we’ll focus on two sets of numbers here: total emissions, and the total amount of mining needed. 

When it comes to emissions, the story is pretty simple: we’ll generate emissions while we build new energy infrastructure, but we’ll avoid a lot more by not burning fossil fuels. At most, we could generate up to 29 billion metric tons of greenhouse-gas emissions building renewable-energy infrastructure. That’s less than one year’s worth of the world’s emissions from fossil fuels today. And the story might turn out even better if we can work out how to cut emissions from steel and cement production or establish robust recycling for some key materials

As for environmental harms beyond climate-related pollution, the picture can be more complicated, and we’ll get more into this when we address the last myth. But for now, let’s consider the sheer mass of mining needed for fossil fuels and for renewable energy. 

About 7.5 billion metric tons of coal were mined in 2021. Estimates for the maximum amount of materials we’ll need annually to build low-emissions energy infrastructure top out at about 200 million metric tons, including all the cement, aluminum, steel, and even glass that needs to be produced. 

So in total, compared with relying on fossil fuels, a transition to renewable energy means both less stuff coming out of the ground and less climate pollution in the form of emissions. 

Myth #3: Renewable and low-carbon energy are “clean” and beyond reproach. 

Even though renewable energy is necessary to combat climate change, there are some major challenges that come along with the transition away from fossil fuels. That includes potential harms from mining and processing the materials used to build these new technologies. 

Take Thacker Pass, the site of a proposed lithium mine in Nevada in the US. The mine could generate the lithium we need to make a million EVs every year. But for the Indigenous people who live in the area and consider the land sacred, that’s not a consolation

Mining can cause pollution, especially water pollution, and communities that live near those mines will bear the brunt. Not only that, but mining in some parts of the world has been linked to human rights abuses, including forced and child labor. Those abuses certainly aren’t limited just to the metals we need for renewable power, but it’s important to remember that efforts to decarbonize the world aren’t immune from those problems. 

We need to cut emissions to address climate change if we want a livable world in the future. And personally, I think we’ll need a lot of new technologies to make that happen. 

How we build those technologies, though, could have a huge influence on their social and environmental ramifications. A recent study, for example, found that lithium demand will be influenced by policies around public transit, vehicle size, and recycling. Finding alternatives and cutting down on how much lithium we use could mean we need to build fewer mines in the future. 

Two things can be simultaneously true, and I think many folks who think a lot about climate change might agree: climate action is necessary, and the way we take that action will matter. 

JOE DELNERO/NREL

Keeping Up with Climate

MIT spinout Boston Metal raised $120 million to scale up its coal-free steelmaking technology. (Canary Media

→ The company uses a process called molten oxide electrolysis, which replaces coal with electricity to make steel. (MIT Technology Review)

Speaking of money, climate tech investments topped $1 trillion in 2022, a new record. And for the first time ever, there was more investment in low-carbon technologies than in oil and gas production. (Bloomberg)

Building new solar and wind is cheaper than running existing coal plants in the US in 99% of cases. Falling costs for renewables and a boost from recent policy are turning coal power into a dinosaur. (Inside Climate News)

As climate change supercharges wildfires in the western US, Colorado is joining other states using AI to track blazes. (Associated Press)

Natural gas is a fossil fuel, but a growing number of companies are trying to sell it as “green.” (Canary Media

Climate change is coming for another one of my favorite things: fancy ham. To make Spanish jamón ibérico bellota, pigs have to eat acorns for the last month of their lives. But oak trees are producing fewer acorns because of unusually hot, dry summers. (The Guardian)

Cheaper lithium-ion batteries are coming to the US. Lithium iron phosphate (LFP) batteries don’t use expensive cobalt and nickel, and now production is spreading outside China. (Chemical and Engineering News)

→ I talked about these low-cost batteries in a story about what’s coming up for the industry this year. If you haven’t read it yet, check it out for all my 2023 predictions. (MIT Technology Review