4 ms·

I've passively followed the perovskite revolution for a while now, and the constant claim is that they're cheaper. But how cheap? Nobody can ever seem to quanti

I've passively followed the perovskite revolution for a while now, and the constant claim is that they're cheaper. But how cheap? Nobody can ever seem to quantify it.

jayrot 6y ago
No idea if it applies here or not, but a general rule of thumb is if they don't how say how much cheaper...it's not that much cheaper. "new solar cells are 94% of the price than existing mono-crystalline cells"
philipkglass 6y ago
The raw materials for perovskite cells are cheap, but so are the raw materials for silicon cells. There won't be hard cost numbers on perovskite PV modules until they go into volume manufacturing. They won't go into volume manufacturing until they can be stabilized enough to last years in the field. My personal guess is that single-junction perovskite cells will not ever overtake single-junction silicon cells for rooftop or utility scale solar. Single junction perovskite cells may be used in applications where light weight and flexibility are advantageous, like charging portable electronics, if they can be stabilized. Perovskite cells may compete in rooftop/utility solar with conventional silicon when incorporated into tandem cell designs -- either perovskite on silicon or a stack of different perovskites with different band gaps. That gives them the potential to exceed conventional crystalline silicon module efficiency rather than merely play catch-up. The company that seems to be furthest along with this approach is Oxford PV, which is pursuing a perovskite/silicon tandem design: https://www.oxfordpv.com/perovskite-silicon-tandem https://www.oxfordpv.com/perovskite-silicon-tandem
- powerslacker 6y ago
  Full disclosure, I know next to nothing about solar markets. What about putting panels on vehicles? Couldn't the market for cells on vehicles overtake the existing solar market?
  - philipkglass 6y ago
    There isn't enough surface area on vehicles for that to happen. The world installed about 117 gigawatts (peak) of solar PV last year [1]. If the average panel is 17% efficient that's more than 680 million square meters of panels being manufactured per year. World motor vehicle production in 2018 was 96 million [2]. To put more solar panels on vehicles than we already put in fields and on rooftops, the average vehicle would need more than 7 square meters of surface covered with panels. That's neglecting that most vehicles are still internal combustion vehicles that couldn't do much with the electricity those panels would generate. [1] https://en.wikipedia.org/wiki/Growth_of_photovoltaics https://en.wikipedia.org/wiki/Growth_of_photovoltaics [2] https://en.wikipedia.org/wiki/List_of_countries_by_motor_vehicle_production https://en.wikipedia.org/wiki/List_of_countries_by_motor_veh...
    - woodandsteel 6y ago
      >There isn't enough surface area on vehicles for that to happen. Yeah, it's the old square-cube law in action.
  - nimos 6y ago
    Just not enough room really. Maybe(read: no) you could get 5m^2 of panels on a car. With 100% efficient panels the energy would be 5 * 1000 W m^2 = 5000 watts which is about 7 horse power. That is a bit below what a very aerodynamic car needs to maintain highway speed so sort of relevant from a range extension perspective but 100% efficient panels and 5m^2 being fully illuminated at once are not very realistic assumptions. I could see electric trucks(non commuting) + tiny home on wheel with big arrays potentially being viable though. That + starlink would make a pretty cool working remote combo.
  - ctdonath 6y ago
    All factors considered, solar panels average 10-20 watts/m^2. A Tesla uses ~325Wh/mile, Leaf ~250, Cybertruck ~500. Putting PV panels on a vehicle can give you a few miles per day - enough to get you to a plug if battery drains too low. More an emergency tool than viable power source.
kragen 6y ago
If you're making something in a laboratory, it's not cheap, even if it could conceivably be cheap in mass production. Even once something is in mass production — like silicon PV has been for the last 40 years — it can take a long time to bring the cost down. Silicon PV cells have fallen in cost by a factor of 10 in the last 10 years, in part due to much higher volumes, in part because the production lines no longer need to be staffed by Ph.D.s. Who could have predicted in 1980 that that would take until 2015? In a lab you can demonstrate how much material something uses, how long it lasts under given conditions, and, say, how sensitive it is to contamination. But you can't predict, you know, the late-oughties polysilicon price bubble, the ensuing long-term purchase agreements made by companies like Evergreen, and the subsequent polysilicon price collapse that sunk those companies. (I'm still not sure where modern PV cell companies source their silicon! Is it UMG?) "How cheap?" is a question about international trade, mining, and management, not a question about materials science. Don't expect materials scientists to be able to answer it.

I've passively followed the perovskite revolution for a while now, and the constant claim is that they're cheaper. But how cheap? Nobody can ever seem to quantify it.

jayrot 6y ago

No idea if it applies here or not, but a general rule of thumb is if they don't how say how much cheaper...it's not that much cheaper. "new solar cells are 94% of the price than existing mono-crystalline cells"

philipkglass 6y ago

The raw materials for perovskite cells are cheap, but so are the raw materials for silicon cells. There won't be hard cost numbers on perovskite PV modules until they go into volume manufacturing. They won't go into volume manufacturing until they can be stabilized enough to last years in the field. My personal guess is that single-junction perovskite cells will not ever overtake single-junction silicon cells for rooftop or utility scale solar. Single junction perovskite cells may be used in applications where light weight and flexibility are advantageous, like charging portable electronics, if they can be stabilized. Perovskite cells may compete in rooftop/utility solar with conventional silicon when incorporated into tandem cell designs -- either perovskite on silicon or a stack of different perovskites with different band gaps. That gives them the potential to exceed conventional crystalline silicon module efficiency rather than merely play catch-up. The company that seems to be furthest along with this approach is Oxford PV, which is pursuing a perovskite/silicon tandem design: https://www.oxfordpv.com/perovskite-silicon-tandem https://www.oxfordpv.com/perovskite-silicon-tandem

powerslacker 6y ago
Full disclosure, I know next to nothing about solar markets. What about putting panels on vehicles? Couldn't the market for cells on vehicles overtake the existing solar market?
- philipkglass 6y ago
  There isn't enough surface area on vehicles for that to happen. The world installed about 117 gigawatts (peak) of solar PV last year [1]. If the average panel is 17% efficient that's more than 680 million square meters of panels being manufactured per year. World motor vehicle production in 2018 was 96 million [2]. To put more solar panels on vehicles than we already put in fields and on rooftops, the average vehicle would need more than 7 square meters of surface covered with panels. That's neglecting that most vehicles are still internal combustion vehicles that couldn't do much with the electricity those panels would generate. [1] https://en.wikipedia.org/wiki/Growth_of_photovoltaics https://en.wikipedia.org/wiki/Growth_of_photovoltaics [2] https://en.wikipedia.org/wiki/List_of_countries_by_motor_vehicle_production https://en.wikipedia.org/wiki/List_of_countries_by_motor_veh...
  - woodandsteel 6y ago
    >There isn't enough surface area on vehicles for that to happen. Yeah, it's the old square-cube law in action.
- nimos 6y ago
  Just not enough room really. Maybe(read: no) you could get 5m^2 of panels on a car. With 100% efficient panels the energy would be 5 * 1000 W m^2 = 5000 watts which is about 7 horse power. That is a bit below what a very aerodynamic car needs to maintain highway speed so sort of relevant from a range extension perspective but 100% efficient panels and 5m^2 being fully illuminated at once are not very realistic assumptions. I could see electric trucks(non commuting) + tiny home on wheel with big arrays potentially being viable though. That + starlink would make a pretty cool working remote combo.
- ctdonath 6y ago
  All factors considered, solar panels average 10-20 watts/m^2. A Tesla uses ~325Wh/mile, Leaf ~250, Cybertruck ~500. Putting PV panels on a vehicle can give you a few miles per day - enough to get you to a plug if battery drains too low. More an emergency tool than viable power source.

kragen 6y ago

If you're making something in a laboratory, it's not cheap, even if it could conceivably be cheap in mass production. Even once something is in mass production — like silicon PV has been for the last 40 years — it can take a long time to bring the cost down. Silicon PV cells have fallen in cost by a factor of 10 in the last 10 years, in part due to much higher volumes, in part because the production lines no longer need to be staffed by Ph.D.s. Who could have predicted in 1980 that that would take until 2015? In a lab you can demonstrate how much material something uses, how long it lasts under given conditions, and, say, how sensitive it is to contamination. But you can't predict, you know, the late-oughties polysilicon price bubble, the ensuing long-term purchase agreements made by companies like Evergreen, and the subsequent polysilicon price collapse that sunk those companies. (I'm still not sure where modern PV cell companies source their silicon! Is it UMG?) "How cheap?" is a question about international trade, mining, and management, not a question about materials science. Don't expect materials scientists to be able to answer it.