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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

#61

Post by nitrogen »

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…

While you're considering alternatives, what would the massive wealth dedicated to the DOD have done in the hands of NASA and private non-military researchers?

Re: World record solar cell with 44.7% efficiency

#62

Post by scarmig »

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…

A couple points:

1) It's not like the Soviet Union was a terrible hellhole for research. It had impressive research output for decades.

2) That's almost beside the point, however. Let's take it as a given that more good research, whatever that is, is a worthy goal for a society, and that the market under-invests in it in favor of short term profits. It's obviously not a binary of either 100% government funding or 100% private; it's not even really a one-dimensional continuum, because for the large capital expenditures typically involved in research, the government always has a heavy involvement, either in tax breaks or grants or collaboration. The question is, how do we allocate money to produce the best research? It's undoubtedly at some value that's somewhere between 0% and 100%.

3) There's a whole lot of money floating around now that makes endeavors like SpaceX practicable. That wasn't the case in, say, the Sixties. Even if the arguments for government spending on research were weak now, they'd be stronger in the 1960's, particularly for things like space exploration that required substantial concentrations of capital.

Re: World record solar cell with 44.7% efficiency

#63

Post by asab »

nazgulnarsil wrote: post #31
greglindahl wrote: post #9

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

There aren't even error bars in the article's graphs

Re: World record solar cell with 44.7% efficiency

#64

Post by snippyhollow »

scarmig wrote: post #62
dpatru wrote: post #54

Earlier quoted context omitted.

> 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…

A couple points: 1) It's not like the Soviet Union was a terrible hellhole for research. It had impressive research output for decades. 2) That's almost beside the point, however. Let's take it as a given that more good research, whatever that is, is a worthy goal for a society, and that the market under-invests in it in favor of short term profits. It's obviously not a binary of either 100% government funding or 100…

As great as SpaceX is, at least half of its funding comes from NASA https://en.wikipedia.org/wiki/SpaceX#Funding

Re: World record solar cell with 44.7% efficiency

#66

Post by reitzensteinm »

tsotha wrote: post #59
evolve2k wrote: post #57

Earlier quoted context omitted.

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. Th…

In addition, the home owners are selling a electricity at a fixed time and buying it back with flexibility, not taking into account the spot price of the electricity (which is going to lower drastically during peak solar times over the next few decades).

If every home owner installed sufficient solar power to be neutral under net metering, the grid would have to be maintained, with traditional generation supplied at off peak solar times at no cost to the home owner.

If that doesn't show how heavy a subsidy net metering is, I don't know what will. It's not sustainable and should never be used to price out solar.

Re: World record solar cell with 44.7% efficiency

#67

Post by kyberias »

nazgulnarsil wrote: post #31
greglindahl wrote: post #9

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

Care to elaborate?

Re: World record solar cell with 44.7% efficiency

#68

Post by bsullivan01 »

ars wrote: post #46
bsullivan01 wrote: post #37

Earlier quoted context omitted.

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 :-)

Less space means less installation costs, and it means less raw materials. Silicon is OK, but some of the other stuff doesn't exist on earth in sufficient quantity to use solar energy in quantity.

I was thinking in terms of doing more. Not just heating water for example, but maybe even cook or heat a few rooms during the daytime.

Re: World record solar cell with 44.7% efficiency

#69

Post by regularfry »

rocco wrote: post #58

Guys, anyone knows the sense of "measured at a concentration of 297 suns."? is sufficient much less energy to transform the earth in a giant BBQ.

It's a concentrator cell, so it's designed to be used with reflectors or lenses to increase the sunlight capture area.

A rough rule of thumb is that you get 1kW/m^2 of raw sunlight, so to get reasonable powers (in the MW+ range) out of a solar installation without needing an enormous solar cell budget, you need cheap concentrators of some sort.

Re: World record solar cell with 44.7% efficiency

#70

Post by regularfry »

tomasien wrote: post #5

I'm going to turn to Hacker News, as I always do, for context: what would 50% efficiency mean?

Where nowadays you might put a 2kW installation on your roof (using 14%-ish efficient cells as are currently available), you'd be able to fit a 7kW installation in the same space, start putting 2kW installations on houses with much smaller available roof area, or start using solar effectively in much more overcast areas.

2kW is a usable approximation for the total power usage of an "average" house.

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