Odd that the figure says that the efficiency was 44.7% +/- 3.1% -- given the big error bar, how could they say they'd increased 1% in 4 months? Measure it again, who knows what you'll get!
ERROR BARS DO NOT WORK THAT WAY
World record solar cell with 44.7% efficiency
31–40 of 127 posts
Re: World record solar cell with 44.7% efficiency
#32Earlier quoted context omitted.
This is the fundamental problem with PV. Compared to cheap natural gas, there just isn't much future in it
No Future? That might be true, except for that rather large elephant in the room call human-induced climate change.
yes and PP presupposes "cheap natural gas." as witnessed by recent fracking-induced earthquakes [1] there may be very little cheap natural gas in the future.
Re: World record solar cell with 44.7% efficiency
#33Re: World record solar cell with 44.7% efficiency
#34"These solar cells are used in concentrator photovoltaics (CPV), a technology which achieves more than twice the efficiency of conventional PV power plants in sun-rich locations. The terrestrial use of so-called III-V multi-junction solar cells, which originally came from space technology, has prevailed to realize highest efficiencies for the conversion of sunlight to electricity. In this multi-junction solar cell, s…
It is indeed interesting, but IIRC most of the funding for satellite launches (R&D for III-V semiconductors) came from intelligence, not NASA. So, um, thank you, NSA! :P
I thought it was the NRO?
http://www.nro.gov/about/
Re: World record solar cell with 44.7% efficiency
#35Good on them. In reality, however, fuel from the sun is free and we have unlimited land. Getting the cost down and economies of scale are what everyone is really focussed on.
Re: World record solar cell with 44.7% efficiency
#36Earlier quoted context omitted.
It's worse than that. There's no room for a single doubling of 44% efficiency. The theoretical maximum for multi-junction concentrator cells is about 86%: https://en.wikipedia.org/wiki/Shockley–Queisser_limit For single junction cells it's a mere 33%.
Efficiency matters, but price/watt matters more and there's still room for a kind of moore's law there.
Which of efficiency or price/watt matters more depends on the application.
For example, I believe something like 4 m^2, 40% efficient, 8 hours of charging is enough to get electricity to drive a Tesla something like 30-40 miles. (In practice, I assume you'd cover all of the outside of the car with 40% efficient solar panels to make this work (or maybe even 80% if you can figure out how to build them), and then 4 m^2 approximates the effective useful area after you take into account suboptimal sun angle, the side of the car facing away from the sun, etc.) The number of people whose commutes could be entirely covered by 40% efficient solar panels built into the car being used to recharge the battery is a lot more than the number of people whose commutes could be covered entirely by 12-15% efficient solar panels. Current mass produced technology doesn't make any variation on this cost effective today, but it seems clear that in the future, a 12% efficient panel array built into a Tesla is never going to be all that attractive for this application no matter how cheap it might become.
I suspect that high rise apartment buildings can cover a much larger percentage of their energy consumption from solar panels mounted on their sides and roof if those solar panels are 40-80% efficient instead of 12-15% efficient. If localized solar right next to the consumer of the power becomes cheaper than paying for electric grid transmission, this may become very relevant in 10 or 20 years.
Even for residential suburban solar installation, where finding adequate space for an adequate quantity 12% efficient solar panels is generally not a problem, the really important thing is not the price per watt of the panels themselves, but the price per watt of the system as a whole. The mechanical support of the panels is a part of the system cost, and the cost of that portion will shrink with more efficient solar panels, though of course there is an open question as to whether that will end up lowering the total system cost or not in the long run.
Re: World record solar cell with 44.7% efficiency
#37Earlier quoted context omitted.
>I think we may start to see Moore's Law starting to be applied to Solar Cells. It would have to be a kind of inverse Moore's law, given that you can't double beyond 100%.
It's worse than that. There's no room for a single doubling of 44% efficiency. The theoretical maximum for multi-junction concentrator cells is about 86%: https://en.wikipedia.org/wiki/Shockley–Queisser_limit For single junction cells it's a mere 33%.
Interesting.
Considering that solar is essentially "free" after you buy the equipment, something like Moore's Law can be applied to the price of solar panels or their longevity. We got plenty of space in our roofs :-)
Re: World record solar cell with 44.7% efficiency
#38Good on them. In reality, however, fuel from the sun is free and we have unlimited land. Getting the cost down and economies of scale are what everyone is really focussed on.
We have unlimited land, but I don't think we have unlimited Silicon with which to cover it.
Re: World record solar cell with 44.7% efficiency
#39So when does solar power become cheap and efficient enough that it's a real game changer? It seems like the numbers have gotten a lot better in recent years, at least in terms of efficiency.
Re: World record solar cell with 44.7% efficiency
#40Earlier quoted context omitted.
>I think we may start to see Moore's Law starting to be applied to Solar Cells. It would have to be a kind of inverse Moore's law, given that you can't double beyond 100%.
It's worse than that. There's no room for a single doubling of 44% efficiency. The theoretical maximum for multi-junction concentrator cells is about 86%: https://en.wikipedia.org/wiki/Shockley–Queisser_limit For single junction cells it's a mere 33%.
One way of counting efficiency is by looking at waste. In that view, a 44% efficient process becoming "twice as efficient" means that it's half as wasteful, not that it's 88% efficient.
In other words, a 44% efficient process which doubles in efficiency by this measure is now 72% efficient.