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World record solar cell with 44.7% efficiency

phys.org

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Re: World record solar cell with 44.7% efficiency

#51

Post by frabcus »

paul_f wrote: post #22
twelvechairs wrote: post #17

this is great but its worth noting that efficiency isn't really what's holding solar production back, its price. few peoples roofs are crammed with PV to the point where they can't fit more in.

This is the fundamental problem with PV. Compared to cheap natural gas, there just isn't much future in it

Price per watt of solar PV is on an exponentially improving trend line, since the late 1970s.

http://cleantechnica.com/2013/05/24/solar-powers-massive-pri...

Natural gas is, well, much less predictable. But hasn't gone below its 1990s price.

http://www.tradingeconomics.com/commodity/natural-gas

Re: World record solar cell with 44.7% efficiency

#54

Post by dpatru »

TheLegace wrote: post #2

"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…

> If that isn't a reason to be investing in Space, I don't know what is.

To justify government research, the results need to be compared to the alternative. Had NASA scientists not been working for the government, they would have been working for private companies engaged doing useful work. The Soviet Union had similar resources to the US, yet their research budget was spent wholly by government, whereas a large portion of the US research during that time was directed by private companies. If you want to restrict the comparison just to the US, ask yourself what would the massive wealth that was dedicated to NASA had produced had it been directed by private interests? What would NASA engineers have produced had they been employed by in Y-Combinator-style startups? (or even big private companies like Google, Apple, Facebook, Amazon, etc.)

Re: World record solar cell with 44.7% efficiency

#55

Post by scythe »

jws wrote: post #29
twelvechairs wrote: post #17

this is great but its worth noting that efficiency isn't really what's holding solar production back, its price. few peoples roofs are crammed with PV to the point where they can't fit more in.

Gains in efficiency can also be looked at as reductions in installation costs, for a given capacity. They can support a greater price premium than just the extra power would command.

The cost of solar today is dominated not by panels, but by conversion and installation. Typical solar panels these days are about $0.80/watt, but installation hovers around $3/watt. The former is competitive with fossil fuels; the latter is not.

So the efficiency gain is actually very good, because current panels are on average 14% (iirc) efficient. If that can be raised to 42% the installation drops to $1, for example; with a few more gains here and there you're golden. The difficulty is in manufacturing these things; thin films are easy, this is not.

Re: World record solar cell with 44.7% efficiency

#56

Post by dmckeon »

ck2 wrote: post #47

While nearly 45% is impressive, I'd rather see "cheap as paint" solar cells at 10% efficiency that are football fields in size. Put them on every commercial rooftop and all that free space we have out west in the USA.

It is an interesting challenge for a PV-curious homeowner - if efficiency is increasing, and capital costs are dropping, and assuming that rooftop cells might eventually need replacing - it is better to cover one's roof all at once with current tech, or to start smaller and plan to add new panels over time until the roof is full, and then start replacing old panels?

Local variables would probably predominate, along with loan/lease/financing and ability to resell.

Re: World record solar cell with 44.7% efficiency

#57

Post by evolve2k »

tsotha wrote: post #50
dgreensp wrote: post #39

So 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.

Solar is already cheaper in most places provided you have net metering, which is a subsidy. But there's a limit to how many people can use the grid for free.

Don't forget to take into account that grid connected solar houses feed excess power produced into the grid, there's no free about it, these are essentially micro power stations which enhance the grid.

Re: World record solar cell with 44.7% efficiency

#59

Post by tsotha »

evolve2k wrote: post #57
tsotha wrote: post #50

Earlier quoted context omitted.

Solar is already cheaper in most places provided you have net metering, which is a subsidy. But there's a limit to how many people can use the grid for free.

Don't forget to take into account that grid connected solar houses feed excess power produced into the grid, there's no free about it, these are essentially micro power stations which enhance the grid.

You're missing the point. The free part is they're selling back power at retail rates. In net metering if you generate as much power as you use you don't pay any per kWh charges. Where I live the power company is selling power to consumers for about 22 cents per kWh. From normal wholesale vendors it's buying power for somewhere around seven cents, but it's buying buying power from net metering people for 22 cents.

That's where the "using the grid for free" part comes in. People who purchase wholesale-generated power are paying the power company's overhead, whereas the net metering people aren't.

Re: World record solar cell with 44.7% efficiency

#60

Post by eru »

dpatru wrote: post #54
TheLegace wrote: post #2

"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…

> If that isn't a reason to be investing in Space, I don't know what is. To justify government research, the results need to be compared to the alternative. Had NASA scientists not been working for the government, they would have been working for private companies engaged doing useful work. The Soviet Union had similar resources to the US, yet their research budget was spent wholly by government, whereas a large port…

> (or even big private companies like Google, Apple, Facebook, Amazon, etc.)

Or IBM, or everyone's favourite, Tesla.

A similar argument always crops up with people always looking at how much technology came out of war-time efforts. The opportunity costs are huge.

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