How far are perovskite solar cells?

[Arthur Hanson]

From my reading perovskite solar cells are the future. Efficiencies and their potential are all over the map from my reading. Any thoughts or information on these solar cells or other types appreciated. It seems solar cells mounted on the car could reach thirty miles a day from my reading. Any thoughts or observations on this appreciated, especially on what companies will take the lead, THANKS.

 

[Paul2]

Very very far. It has disproportionate publicity because the name sounds exotic, and the money, today ,follow the pattern of following something thought to be rare, weird, and exotic.

 

[Xebec]

Very very far. It has disproportionate publicity because the name sounds exotic, and the money, today ,follow the pattern of following something thought to be rare, weird, and exotic.

+1 - also the solar industry has been a bit of a race to the bottom on cost, not leaving a lot of room for really premium cells.

 

[IanD]

+1 - also the solar industry has been a bit of a race to the bottom on cost, not leaving a lot of room for really premium cells.

Not surprising because the worldwide mass solar panel market is clearly driven by kW/$, not kW/m2 where "really premium cells" are targeted.

There are a few applications where kW/m2 wins (e.g. boats and RVs where there's a hard limit on area) but these are tiny markets in comparison to grid solar arrays.

So more efficient technologies like multilayer cells (e.g. perovskite-on-silicon) will only take off big-time when their cost equals that of silicon panels -- which are made in enormous volumes today which drives the cost down, so it's difficult for a new technology to compete unless it can be made in volume in the same factories with the same equipment.

Which may well be possible for perovskite-on-silicon, but will never happen for the exotic multilayer cells using expensive raw materials which keep making the efficiency headlines...

 

[mattyenright]

Not close. The latest perovskite cells suffer greatly from stability and environmental degradation issues. Along with using lead-based compounds (e.g., PbI2), and distinct equipment processes (e,g. slot-die coating or ink jet printing).

Solving all these conditions will take decades to achieve a comparable cost relative to silicon today. Tandem based structures will most likely be released over the next decade and will form a more niche market for high kW/m2 situations.

It’s important to note that media Headlines almost universal emphases the positive aspects, while neglecting to fully explain the downsides, subsequently causing an exaggeration of the expectations of emerging technology. (e.g. fully driverless cars).

 

[IanD]

Not close. The latest perovskite cells suffer greatly from stability and environmental degradation issues. Along with using lead-based compounds (e.g., PbI2), and distinct equipment processes (e,g. slot-die coating or ink jet printing).

Solving all these conditions will take decades to achieve a comparable cost relative to silicon today. Tandem based structures will most likely be released over the next decade and will form a more niche market for high kW/m2 situations.

It’s important to note that media Headlines almost universal emphases the positive aspects, while neglecting to fully explain the downsides, subsequently causing an exaggeration of the expectations of emerging technology. (e.g. fully driverless cars).

Which is what I said -- to take over the mass market "new technology" solar cells (like perovskite-on-silicon) have to be competitive on kW/$ with conventional monosilicon cells -- and the cost obviously includes both manufacturing cost and lifetime (and cost to replace them when they die), so if they have shorter lifetime they have to be even cheaper to make.

Some panel manufacturers have said they can be made on existing production lines, but obviously there must be more production steps to add the perovskite layer so this will put the cost per m2 up. Probably by less than the savings due to increased efficiency, but only as long as lifetime is comparable. If the lifetime problem can be solved, then they'll probably end up cheaper per kW as well as smaller size for the same power -- but it isn't solved yet.

As you say, solar panels and batteries both suffer from the "FANTASTIC NEW BREAKTHROUGH!!!" headlines which almost always ignore realities like scaling up and raw material cost/availability -- mono solar panels use dirt cheap materials and can be made cheaply in massive volumes, and this is a huge hill to climb for anything "better"...

 

[peter]

Short answer: single junction perovskite panels, very very unlikely to see anytime soon. Tandem junction, possibly not too far away.

As others have pointed out above, perovskite cells by themselves do suffer from output degradation at rates a bit higher than current conventional monocrystalline p-type perc panels and n-type panels, so a single junction panel will not be competitive with the status quo. But for tandem junction cells where there's a conventional monocrystalline silicon layer plus the perovskite layer, the degredation rate isn't nearly as bad simply due to the fact you have the conventional layer there that doesn't degrade anywhere near as rapidly, and the cost delta to apply the perovskite layer is fairly trivial and could be potentially come on the market in the next few years.

A couple of the tier 1 module manufacturers have built cells in MW quantities and deployed them on solar farms to test the degradation rates and at least for GCL, they've publicly stated it passed IEC 61215 and 61739 certification tests. The beauty of these multijunction modules is they achieve a higher efficiency rate than the best n-type IBC panels, like Maxeon 7 from SunPower, and most likely, if they were to mass produce the modules right now, it would be priced below those Maxeon 7 modules, which if you're in the industry, you'd know they're some pricey panels.

Solar cells reaching 30 miles a day on a car? Even with some of the best EVs on the market right now, that's some 6kwh of electricity per day, typical car at best would have about 20sqft of usable surface area for solar cells. Assuming even the most optimistic scenario of 8 hours of exposure per day, that's 750wh/hr, or 37.5w/sqft. Current best performance module yields 22.61w/sqft at STC condition. The perovskite tandem panels might get us to 30% efficiency in the next 5 years, that would get us to 27.9w/sqft, still a long ways away from that 37.5w/sqft number. This is some back of the napkin math in the most optimistic scenario, realistically, the numbers are a lot worse than that. And most people don't leave their cars in areas with no shade, and the angle of incidence can drastically reduce output numbers as well as the sun moves across the sky.

Hanwha Q Cells, LONGi and GCL are the ones I consider to be taking the lead, actively investing in R&D and furthest along in commercializing the technology. Any of these other start-offs fiddling around with some novel concept, I don't really see being a serious contender because of the massive undertaking to commercialize production in the multi-GW quantities necessary to compete with the status quo, which I'd say the same for most of the battery tech you see on the news, like IanD pointed out above.

 

[peter]

Speak of the devil, GCL completed a production factory with a 1GW/annual capacity for perovskite modules just a few weeks ago:

GCL Optoelectronics finishes 1 GW perovskite PV module factory in China

GCL Optoelectronics has commissioned a 1 GW perovskite solar module facility in China, and says it may increase capacity to 2 GW per year depending on market demand.

www.pv-magazine.com

So yeah, we're not that far away, it'll be incremental improvements, just as we've seen in the solar and battery industry to date. Solar's gone from 14% polycrystalline silicon to monocrystalline silicon to poly p-type perc, mono p-type perc, mono n-type, n-type topcon, n-type hjt, n-type ibc exceeding 24% in the past 15 years, and witnessed a price drop from over $100/w in 1975 to $0.07/w in 2025. A 1% improvement in efficiency in the solar industry is huge and tandem junction with perovskite can definitely open the pathway to +30% efficiency and get us past the Shockley Queisser limit for a single junction silicon cell.

 

[IanD]

Speak of the devil, GCL completed a production factory with a 1GW/annual capacity for perovskite modules just a few weeks ago:

GCL Optoelectronics finishes 1 GW perovskite PV module factory in China

GCL Optoelectronics has commissioned a 1 GW perovskite solar module facility in China, and says it may increase capacity to 2 GW per year depending on market demand.

www.pv-magazine.com

So yeah, we're not that far away, it'll be incremental improvements, just as we've seen in the solar and battery industry to date. Solar's gone from 14% polycrystalline silicon to monocrystalline silicon to poly p-type perc, mono p-type perc, mono n-type, n-type topcon, n-type hjt, n-type ibc exceeding 24% in the past 15 years, and witnessed a price drop from over $100/w in 1975 to $0.07/w in 2025. A 1% improvement in efficiency in the solar industry is huge and tandem junction with perovskite can definitely open the pathway to +30% efficiency and get us past the Shockley Queisser limit for a single junction silicon cell.

Yes the bit in bold is correct, but it will only happen in multi-GW quantities if they cost no more per kW than single-layer silicon cells and have proved to be long-lasting.

If they also cost less per GW (because a given size panel has more output) then it'll be a no-brainer, the entire industry will pivot to them as fast as the production lines can be switched over.

So what matters isn't the higher efficiency, that's a given -- it's the cost, because that's what drives the multi-GW market.

 

[peter]

Yes the bit in bold is correct, but it will only happen in multi-GW quantities if they cost no more per kW than single-layer silicon cells and have proved to be long-lasting.

If they also cost less per GW (because a given size panel has more output) then it'll be a no-brainer, the entire industry will pivot to them as fast as the production lines can be switched over.

So what matters isn't the higher efficiency, that's a given -- it's the cost, because that's what drives the multi-GW market.

The numbers I'm hearing in terms of additional cost for the perovskite layer is a penny or two per watt, which is less than the variation in price between modules from suppliers out there, especially if we factor in modules made here in the US or countries outside of China. Price range for N type modules right now range from 7 cents to 10 cents/watt so I see cost being a factor that can be overlooked. The long-lasting part you mention is a little harder to consider, this is where companies like SunPower and other "premium" suppliers get to really charge a hefty surcharge with carrots like 40 year warranties, for whatever that's worth, some developers are more than willing to buy in to that, others don't really care. I think in this day and age, pretty much all the tier 1 module suppliers offer 25 year/>80% power output guarantees, if not, much higher, and if it's a tandem junction anyway, you'll still have that silicon layer's output that's well known/mature enough to fall back on.

I think initially, that's what these modules makers will push with the tandem junction panels, that higher efficiency value. These N-type modules all put out 25 year/>87% numbers, if they're achieving 25 year/>80% with the perovskite layer, should be good enough. Now that there's a factory built specifically for the production of these panels, I suppose we'll find out soon enough if the numbers work to justify the production/sales of these panels. We're kinda screwed over with all the tariffs here in the US and the loss of tax credits, but if the rest of the world can get their hands on 27-30% efficiency modules at under 10 cents/watt, LCOE per kwh for solar will drop below a penny, that'd be pretty frickin amazing! *of course, not factoring storage