Advanced solar panels still need to pass the test of time

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

It must be tough to be a solar panel. They’re consistently exposed to sun, heat, and humidity—and the panels installed today are expected to last 30 years or more.

But how can we tell that new solar technologies will stand the test of time? I’m fascinated by the challenge of predicting how new materials will hold up in decades of tough conditions. That’s been especially tricky for one emerging technology in particular: perovskites. They’re a class of materials that developers are increasingly interested in incorporating into solar panels because of their high efficiency and low cost. 

The problem is, perovskites are notorious for degrading when exposed to high temperatures, moisture, and bright light … all the things they’ll need to withstand to make it in the real world. And it’s not as if we can sit around for decades, testing out different cells in the field for the expected lifetime of a solar panel—climate change is an urgent problem. The good news: researchers have made progress in both stretching out the lifetime of perovskite materials and working out how to predict which materials will be winners in the long run. 

There’s almost constant news about perovskite solar materials breaking records. The latest such news comes from Oxford PV—in January, the company announced that one of its panels reached a 25% conversion efficiency, meaning a quarter of the solar energy beaming onto the panel was converted to electricity. Most high-end commercial panels have around a 20% efficiency, with some models topping 23%. 

The improvement is somewhat incremental, but it’s significant, and it’s all because of teamwork. Oxford PV and other companies are working to bring tandem solar technology to the market. These panels are basically sandwiches that combine layers of silicon (the material that dominates today’s solar market) and perovskites. Since the two materials soak up different wavelengths of light, they can be stacked together, adding up to a more efficient solar material. 

We’re seeing advances in tandem technology, which is why we named super-efficient tandem solar cells one of our 2024 Breakthrough Technologies. But perovskites’ nasty tendency to degrade is a major barrier standing in the way. 

Early perovskite solar cells went bad so quickly that researchers had to race across the laboratory to measure their efficiency. In the time it took to get from the area where solar cells were made to the side of the room where the testing equipment was, the materials basically lost their ability to soak up sunlight. 

The lifetime of perovskite materials isn’t nearly this fleeting now, but it’s not clear that the problem has been entirely solved. 

There’s been some real-world testing of new perovskite solar materials, with mixed results. Oxford PV hasn’t published detailed data, though as CTO Chris Case told Nature last year, the company’s outdoor tests show that the best cells lose only about 1% of their efficiency in their first year of operation, a rate that slows down afterwards. 

Other testing in more intense conditions has found less positive results, with one academic study finding that perovskite cells in hot and humid Saudi Arabia lost 20% of their efficiency after one year of operation. 

Those results are for one year of testing. How can we tell what will happen in 30 years? 

Since we don’t have years to test every new material that scientists dream up, researchers often put them through especially punishing conditions in the lab, bumping up the temperature and shining bright lights onto panels to see how quickly they’ll degrade. 

This sort of testing is standard for silicon solar panels, which make up over 90% of the commercial solar market today. But researchers are still working out just how well the correlations with known tests will transfer to new materials like perovskites. 

One of the issues has been that light, moisture, and heat all contribute to the quick degradation of perovskites. But it hasn’t been clear exactly which factor, or combination of them, would be best to apply in the lab to measure how a solar panel would fare in the real world. 

One study, published last year in Nature, suggested that a combination of high temperature and illumination would be the key to accelerated tests that reliably predict real-world performance. The researchers found that high-temperature tests lasting just a few hundred hours (a couple of weeks) translated well to nearly six months of performance in outdoor testing. 

Companies say they’re bringing new solar materials to the market as soon as this year.  Soon we’ll start to really see just how well these tests predict new technologies’ ability to withstand the tough job a commercial solar panel needs to do. I know I’ll be watching. 

Related reading

Read more about why super-efficient tandem solar cells made our list of 10 Breakthrough Technologies in 2024 here.

Here’s a look inside the race to get these next-generation solar technologies into the world.

Perovskites have been hailed as the hot new thing in solar for years. What’s been the holdup? In short: stability, stability, stability. 

SARAH ROGERS/MITTR | GETTY

Explained

Welcome to the wonderful world of virtual power plants (VPPs). While they’re not physical facilities, VPPs could have actual benefits for emissions by stitching together different parts of the grid to help meet electricity demand. 

What exactly is a VPP? How does it work? What does this all mean for climate action? Get the answers to all these questions and more in my colleague June Kim’s latest story.

Two more things 

Scattering small particles in the upper levels of the atmosphere could help reflect sunlight, slowing down planetary warming. While this idea, called solar geoengineering, sounds farfetched, it’s possible that small efforts could get started within a decade, as David Keith and Wake Smith write in a new op-ed. 

Read more about how geoengineering could start, and what these experts are saying we need to do about it, here. 

The US is pausing exports of liquefied natural gas. The move was met with a wide range of reactions and plenty of questions about what it will mean for emissions. 

As Arvind Ravikumar writes in a new op-ed, people are asking all the wrong questions about LNG. Whether this is a good idea depends on what the fuel would be replacing. Read his full take here. 

Keeping up with climate  

In an age of stronger hurricanes, some scientists say our current rating system can’t keep up. Adding a Category 6 could help us designate super-powerful storms. (Inside Climate News)

→ Here’s what we know about hurricanes and climate change. (MIT Technology Review) 

A fringe idea to put massive sunshades in space to cool down the planet is gaining momentum. Or we could, you know, stop burning fossil fuels? (New York Times)

Trains powered by hydrogen are starting to hit the rails. Here’s why experts say that might not be the best use for the fuel. (Canary Media)

According to the sponges, we’ve already sailed past climate goals. Scientists examining the skeletons of creatures called sclerosponges concluded that human-caused climate change has probably raised temperatures by 1.7 °C (3.1 °F) since the late 19th century. (New York Times)

A century-old law you’ve never heard of is slowing down offshore wind in the US. By requiring the use of US-built ships within the country’s waters, the Jones Act is behind some of the speed bumps facing the offshore wind industry. (Hakai Magazine)

→ Here’s what’s next for offshore wind, including when we can expect the first US-built ship to hit the waters. (MIT Technology Review)

Sorting recycling is a tough job, but AI might be able to help. New sorting systems could rescue more plastic from the landfill, though rolling out new technology to sorting facilities will be a challenge. (Washington Post)

Advanced solar panels still need to pass the test of time

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

It must be tough to be a solar panel. They’re consistently exposed to sun, heat, and humidity—and the panels installed today are expected to last 30 years or more.

But how can we tell that new solar technologies will stand the test of time? I’m fascinated by the challenge of predicting how new materials will hold up in decades of tough conditions. That’s been especially tricky for one emerging technology in particular: perovskites. They’re a class of materials that developers are increasingly interested in incorporating into solar panels because of their high efficiency and low cost. 

The problem is, perovskites are notorious for degrading when exposed to high temperatures, moisture, and bright light … all the things they’ll need to withstand to make it in the real world. And it’s not as if we can sit around for decades, testing out different cells in the field for the expected lifetime of a solar panel—climate change is an urgent problem. The good news: researchers have made progress in both stretching out the lifetime of perovskite materials and working out how to predict which materials will be winners in the long run. 

There’s almost constant news about perovskite solar materials breaking records. The latest such news comes from Oxford PV—in January, the company announced that one of its panels reached a 25% conversion efficiency, meaning a quarter of the solar energy beaming onto the panel was converted to electricity. Most high-end commercial panels have around a 20% efficiency, with some models topping 23%. 

The improvement is somewhat incremental, but it’s significant, and it’s all because of teamwork. Oxford PV and other companies are working to bring tandem solar technology to the market. These panels are basically sandwiches that combine layers of silicon (the material that dominates today’s solar market) and perovskites. Since the two materials soak up different wavelengths of light, they can be stacked together, adding up to a more efficient solar material. 

We’re seeing advances in tandem technology, which is why we named super-efficient tandem solar cells one of our 2024 Breakthrough Technologies. But perovskites’ nasty tendency to degrade is a major barrier standing in the way. 

Early perovskite solar cells went bad so quickly that researchers had to race across the laboratory to measure their efficiency. In the time it took to get from the area where solar cells were made to the side of the room where the testing equipment was, the materials basically lost their ability to soak up sunlight. 

The lifetime of perovskite materials isn’t nearly this fleeting now, but it’s not clear that the problem has been entirely solved. 

There’s been some real-world testing of new perovskite solar materials, with mixed results. Oxford PV hasn’t published detailed data, though as CTO Chris Case told Nature last year, the company’s outdoor tests show that the best cells lose only about 1% of their efficiency in their first year of operation, a rate that slows down afterwards. 

Other testing in more intense conditions has found less positive results, with one academic study finding that perovskite cells in hot and humid Saudi Arabia lost 20% of their efficiency after one year of operation. 

Those results are for one year of testing. How can we tell what will happen in 30 years? 

Since we don’t have years to test every new material that scientists dream up, researchers often put them through especially punishing conditions in the lab, bumping up the temperature and shining bright lights onto panels to see how quickly they’ll degrade. 

This sort of testing is standard for silicon solar panels, which make up over 90% of the commercial solar market today. But researchers are still working out just how well the correlations with known tests will transfer to new materials like perovskites. 

One of the issues has been that light, moisture, and heat all contribute to the quick degradation of perovskites. But it hasn’t been clear exactly which factor, or combination of them, would be best to apply in the lab to measure how a solar panel would fare in the real world. 

One study, published last year in Nature, suggested that a combination of high temperature and illumination would be the key to accelerated tests that reliably predict real-world performance. The researchers found that high-temperature tests lasting just a few hundred hours (a couple of weeks) translated well to nearly six months of performance in outdoor testing. 

Companies say they’re bringing new solar materials to the market as soon as this year.  Soon we’ll start to really see just how well these tests predict new technologies’ ability to withstand the tough job a commercial solar panel needs to do. I know I’ll be watching. 

Related reading

Read more about why super-efficient tandem solar cells made our list of 10 Breakthrough Technologies in 2024 here.

Here’s a look inside the race to get these next-generation solar technologies into the world.

Perovskites have been hailed as the hot new thing in solar for years. What’s been the holdup? In short: stability, stability, stability. 

SARAH ROGERS/MITTR | GETTY

Explained

Welcome to the wonderful world of virtual power plants (VPPs). While they’re not physical facilities, VPPs could have actual benefits for emissions by stitching together different parts of the grid to help meet electricity demand. 

What exactly is a VPP? How does it work? What does this all mean for climate action? Get the answers to all these questions and more in my colleague June Kim’s latest story.

Two more things 

Scattering small particles in the upper levels of the atmosphere could help reflect sunlight, slowing down planetary warming. While this idea, called solar geoengineering, sounds farfetched, it’s possible that small efforts could get started within a decade, as David Keith and Wake Smith write in a new op-ed. 

Read more about how geoengineering could start, and what these experts are saying we need to do about it, here. 

The US is pausing exports of liquefied natural gas. The move was met with a wide range of reactions and plenty of questions about what it will mean for emissions. 

As Arvind Ravikumar writes in a new op-ed, people are asking all the wrong questions about LNG. Whether this is a good idea depends on what the fuel would be replacing. Read his full take here. 

Keeping up with climate  

In an age of stronger hurricanes, some scientists say our current rating system can’t keep up. Adding a Category 6 could help us designate super-powerful storms. (Inside Climate News)

→ Here’s what we know about hurricanes and climate change. (MIT Technology Review) 

A fringe idea to put massive sunshades in space to cool down the planet is gaining momentum. Or we could, you know, stop burning fossil fuels? (New York Times)

Trains powered by hydrogen are starting to hit the rails. Here’s why experts say that might not be the best use for the fuel. (Canary Media)

According to the sponges, we’ve already sailed past climate goals. Scientists examining the skeletons of creatures called sclerosponges concluded that human-caused climate change has probably raised temperatures by 1.7 °C (3.1 °F) since the late 19th century. (New York Times)

A century-old law you’ve never heard of is slowing down offshore wind in the US. By requiring the use of US-built ships within the country’s waters, the Jones Act is behind some of the speed bumps facing the offshore wind industry. (Hakai Magazine)

→ Here’s what’s next for offshore wind, including when we can expect the first US-built ship to hit the waters. (MIT Technology Review)

Sorting recycling is a tough job, but AI might be able to help. New sorting systems could rescue more plastic from the landfill, though rolling out new technology to sorting facilities will be a challenge. (Washington Post)

Three climate technologies breaking through in 2024

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

Awards season is upon us, and I can’t get enough. Red-carpet fashion, host drama, heartwarming speeches—I love it all.

I caught the Golden Globes last weekend, and the Grammys and Oscars aren’t far off. But the best awards, in my humble opinion, are the 10 Breakthrough Technologies, MIT Technology Review’s list of the tech that’s changing our world. 

This year’s list dropped on Monday, and I’m delighted to share that not one, not two, but three climate tech items are featured. So for the newsletter this week, let’s take a look at a few of these award-winning technologies you need to know about. (And to honor awards season, I’ll also be assigning them to bonus—and completely unofficial—categories.)

Super-efficient solar cells

Winner: Best Supporting Actor

Solar panels are among the most important, and perhaps the most recognizable, tools to address climate change. But one next-generation solar technology could help solar power get even more efficient, and cheaper: perovskite tandem solar cells. 

Most solar cells use silicon to soak up sunlight and transform it into electricity. But other materials can do this job too, including perovskites, a class of crystalline materials. And because perovskites and silicon absorb different wavelengths of light, the two materials can be stacked like a sandwich to make one super-efficient cell. 

Because of their outstanding support for traditional silicon solar materials, super-efficient perovskite tandem cells are my winner for this year’s Best Supporting Actor award. 

There are definitely barriers to commercializing this technology: perovskites are tricky to manufacture and have historically degraded quickly outside in the elements. But some companies say they’re closer than ever to using the materials to transform commercial solar. Read more about the technology here. 

Enhanced geothermal systems

Winner: Best New Artist

Sucking heat out from the earth is one of the oldest tricks in the book—there’s evidence that humans were using hot springs for heat more than 10,000 years ago. 

We’ve since leveled up, using geothermal energy to produce electricity. But a specific set of factors is needed to harness the energy radiating out of the planet’s core: heat close to the surface, permeable rock, and underground fluid. 

This narrows the potential sites for usable geothermal energy significantly, so a growing number of projects are working to widen access with so-called enhanced geothermal systems. 

An enhanced geothermal system is essentially a human-created geothermal energy source. This often involves drilling down into rock and pumping fluid into it to open up fractures. We’ve seen some recent progress in this field from a handful of companies, including Fervo Energy, which started up a massive pilot facility in 2023 (and made our list of 15 Climate Tech Companies to Watch). 

Because of its spirit of reinvention and innovation, enhanced geothermal systems are my pick for this year’s Best New Artist Award. 

Some of the biggest projects coming are still a few years from coming online, and it could be tough to scale construction on these plants in some places. But enhanced geothermal is definitely a field to keep an eye on. Read more in my colleague June Kim’s write-up here. 

Heat pumps

Winner: Lifetime Achievement

Last, but certainly not least, we have the venerable heat pump. These devices, which can cool and heat using electricity, are a personal favorite climate technology of mine. 

Heat pumps are super efficient, sometimes almost seeming to defy the laws of physics. They don’t really break any laws, physical or otherwise, as I outlined in a deep dive into how the technology works last year.

While they’re not exactly new, heat pumps are definitely breaking through in a new way. The technology outsold gas furnaces for the first time in the US last year, and sales have been climbing around the world. Globally, heat pumps have the potential to cut emissions by 500 million metric tons in 2030—as much as pulling all the cars in Europe today off the roads. 

For their long-standing and ongoing contributions to decarbonization, heat pumps are my choice for this year’s Lifetime Achievement Award. 

It’s going to be tough to get heat pumps into all the places they need to go to meet climate goals. For more on all things heat pumps, check out my write-up here. 

Congratulations to all our winners! Be sure to check out the rest of the list. It includes everything from wearable headsets to innovative new CRISPR treatments. 

And if you’d like to weigh in on one more award, you can vote for our reader-chosen 11th breakthrough technology here. The candidates are some of the other items we considered for the list. I don’t want to unfairly influence you, but you know my heart always goes with batteries, so feel free to vote accordingly …  

Related reading

Technology is always changing. Don’t miss our list of the technologies breaking through in 2024.

Perovskites were supposed to change the solar world. What’s the holdup?

This startup showed that its underground wells can be used as a massive battery.

Everything you need to know about the wild world of heat pumps.

Another thing

AP PHOTO/JULIA NIKHINSON

It’s been a turbulent time for offshore wind power. Projects are getting delayed and canceled left and right, it seems. 

In 2024, some big moments could determine whether these troubles are more of a bump in the road or a sign of more serious issues. For everything you should watch out for in offshore wind, check out my latest story here.

Keeping up with climate  

It’s officially official—2023 was the hottest year on record, according to the EU’s climate service. Check out the details and some stunning graphics on the record-breaking year. (BBC)

A national lab in California made waves in late 2022 when it achieved a huge milestone for fusion research. You may not know that the facility actually had a massive fusion reactor in the 1980s that never got switched on. (MIT Technology Review)

→ Here’s what’s coming next for fusion research, according to the lab’s current director. (MIT Technology Review)

India is rushing to meet growing demand for electricity, and the country is turning to coal to do it. The government plans to roughly double coal production by 2030. (Bloomberg)

One person’s wastewater is another one’s … heat? New systems can harness the heat in wastewater to heat whole neighborhoods. (BBC)

Norway will open up parts of the Norwegian Sea for seabed mining exploration. The country joins nations including Japan, New Zealand, and Namibia that are considering allowing this new industry to operate in their waters. (New York Times)

→ Seabed mining could be a new source of materials for batteries. But environmentalists are worried about the potential harm. (MIT Technology Review)

Lack of charging infrastructure is a huge barrier to EV adoption. Here are three ways to encourage new chargers in charging deserts. (Canary Media)

Rising temperatures means beavers are moving north—and they’re causing trouble. Specifically, the rodents are creating a feedback loop that’s thawing the ground and disrupting ecosystems. (The Guardian)

Chinese automaker BYD is set to take the world by storm. The company sold more plug-in hybrids and EVs than Tesla did in 2023, and is set to continue its rapid growth this year. (Bloomberg)→ BYD was one of our climate tech companies to watch in 2023. (MIT Technology Review)