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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

#71

Post by twelvechairs »

scythe wrote: post #55
jws wrote: post #29

Earlier quoted context omitted.

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 examp…

where are these figures from? seems incredible for installation to be substantially more than the panels in my rxperience. unless 'installation' is including the price of other fixed components (batteries and inverter).

Also 1/3 size does not mean 1/3 installation costs. lots of the underlying figures don't change (truck call out, overhead, installation of other elements, cost of permits, electrical wiring, etc).

Re: World record solar cell with 44.7% efficiency

#72

Post by JanezStupar »

snippyhollow wrote: post #64
scarmig wrote: post #62

Earlier quoted context omitted.

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

I believe that SpaceX would have no problem securing funds from either BRIC, Arabs or even AlQuaeda for that matter.

Re: World record solar cell with 44.7% efficiency

#73

Post by dredmorbius »

For those wondering about the significance of this announcement:

As several people have noted, what matters for solar PV isn't efficiency but cost per Watt. The maximum available energy is 1W/meter^2 at ground. Single-layer PV efficiency is on the order of about 40%. Mutliple-layer cells can reach a maximum of around 80%.

Even with existing efficiencies, the land space necessary to dedicate to solar power for all electrical energy needs is reasonably small. A percent or so of the Earth's surface. The hard part will be fabricating the PV and/or CSP (concentrated solar thermal power) plants to collect that energy, estimates run well over $100 trillion globally (Jacobson & Delucchi).

A key limiting factor in solar, wind, and other intermittent renewables is storage (or baseload / standby power). Assuming you'd want 7 days' total energy output on reserve, there's quite literally not enough lead in the world to build storage for just the US, let alone the rest of the world. Pumped hydro storage is very efficient, but sites are limited. Biomass similarly doesn't scale to present populations. Geothermal is good for 5-20% of power demands depending on locations (and some places such as Iceland might be able to export energy). Thorium reactors look like a plausible bet but require development. Liquid metal / molten salt batteries (such as Donald Sadoway's designs) look like they're both cheap and abundant enough to make the grade, though they're still under development as well.

Solar power does have its equivalent of Moore's Law: Swanson's Law. Solar PV costs fall by 20% with each doubling of capacity. It's held since the 1970s and looks likely to continue. Effectively, costs half about every 3 years. http://www.economist.com/blogs/graphicdetail/2012/12/daily-c...

In short: this is mostly of significance for applications in which space and/or weight are at a premium: satellite or possibly solar-powered aircraft (ultralights or airships most likely). For ground-based generation, look for costs to come down further.

And pray for highly effective storage solutions.

Re: World record solar cell with 44.7% efficiency

#74

Post by anovikov »

dredmorbius wrote: post #73

For those wondering about the significance of this announcement: As several people have noted, what matters for solar PV isn't efficiency but cost per Watt . The maximum available energy is 1W/meter^2 at ground. Single-layer PV efficiency is on the order of about 40%. Mutliple-layer cells can reach a maximum of around 80%. Even with existing efficiencies, the land space necessary to dedicate to solar power for all el…

Not true at all. Your statement about available land is correct of course, but the important part of picture is that the soft costs for construction of solar electric power plants are already much higher than hard costs. And, improving efficiency is a great way to cut them.

Imagine a 10 MW power plant built out of panels with 10% efficiency. If you replace them with 20% efficient panels, you increase output 2x without measurably increasing soft costs - like land provision, fixtures on which the panels stand, installation work, insurance, etc. Only part that will increase will be inverters (not a particulary big item) and thicker cables connecting it to the grid. So, soft costs per watt will fall by 40-45%.

So, given that the wholesale price of solar panels now stand at 40 cent per watt, and even in cheapest countries the complete plant is $2 per watt, increasing efficiencies 2x means building a 2x more powerful plant for about $1.4 per watt (soft costs fall from $1.6 to $1.0 - i.e. they slightly increase but power output doubles) and hard costs stay the same. Big deal.

And almost all of the progress in solar power costs we can have now lies in this field - increase of panel efficiency, not decreasing their costs. Even if panels were free, costs won't fall much...

Of course this article bears no relation to that - these are high concentration cells, and cost to build collectors is already much higher than just buying enough of flat panels... better show me a non-concentrated cell with at least 35% efficiency.

Re: World record solar cell with 44.7% efficiency

#75

Post by pcowans »

dredmorbius wrote: post #73

For those wondering about the significance of this announcement: As several people have noted, what matters for solar PV isn't efficiency but cost per Watt . The maximum available energy is 1W/meter^2 at ground. Single-layer PV efficiency is on the order of about 40%. Mutliple-layer cells can reach a maximum of around 80%. Even with existing efficiencies, the land space necessary to dedicate to solar power for all el…

I think the total energy available at ground level is something closer to 250W/m^2.

Re: World record solar cell with 44.7% efficiency

#76

Post by rorrr2 »

dredmorbius wrote: post #73

For those wondering about the significance of this announcement: As several people have noted, what matters for solar PV isn't efficiency but cost per Watt . The maximum available energy is 1W/meter^2 at ground. Single-layer PV efficiency is on the order of about 40%. Mutliple-layer cells can reach a maximum of around 80%. Even with existing efficiencies, the land space necessary to dedicate to solar power for all el…

Flywheel storage with magnetic bearings in vacuum is very efficient and can be scaled to almost any size.

Beacon Power has been building them on a commercial scale in NY:

https://www.youtube.com/watch?v=ay_NiGu7mis

Re: World record solar cell with 44.7% efficiency

#78

Post by forgottenpaswrd »

dredmorbius wrote: post #73

For those wondering about the significance of this announcement: As several people have noted, what matters for solar PV isn't efficiency but cost per Watt . The maximum available energy is 1W/meter^2 at ground. Single-layer PV efficiency is on the order of about 40%. Mutliple-layer cells can reach a maximum of around 80%. Even with existing efficiencies, the land space necessary to dedicate to solar power for all el…

"The maximum available energy is 1W/meter^2 at ground"

Where are you from, Britain?

http://en.wikipedia.org/wiki/Sunlight

""sunshine duration" to mean the cumulative time during which an area receives direct irradiance from the Sun of at least 120 watts per meter"

"The total amount of energy received at ground level from the sun at the zenith is 1004 watts per square meter"

This depends on altitude of course, the maximum is over 1300W in space.

Re: World record solar cell with 44.7% efficiency

#79

Post by yungchin »

forgottenpaswrd wrote: post #78
dredmorbius wrote: post #73

For those wondering about the significance of this announcement: As several people have noted, what matters for solar PV isn't efficiency but cost per Watt . The maximum available energy is 1W/meter^2 at ground. Single-layer PV efficiency is on the order of about 40%. Mutliple-layer cells can reach a maximum of around 80%. Even with existing efficiencies, the land space necessary to dedicate to solar power for all el…

"The maximum available energy is 1W/meter^2 at ground" Where are you from, Britain? http://en.wikipedia.org/wiki/Sunlight ""sunshine duration" to mean the cumulative time during which an area receives direct irradiance from the Sun of at least 120 watts per meter" "The total amount of energy received at ground level from the sun at the zenith is 1004 watts per square meter" This depends on altitude of course, the max…

Hah, not even in Britain does it get that bad :) http://www.withouthotair.com/c6/page_38.shtml - see fig 6.2

Re: World record solar cell with 44.7% efficiency

#80

Post by JoeAltmaier »

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…

The real reason is, all the solar cell numbers are fake. Its dark around here (and everywhere else) an average of 50% of the time. In space, its bright (brighter than on the ground) around 90% of the time.

Terrestrial solar cells MUST account for this when comparing efficiencies. So this new cell is 23% efficient, versus 46% if deployed orbitally, before accounting for the increased solar intensity in space.

Elon Musk is famously quoted as criticizing space-based solar plants because of the supposed inefficiencies in transmitting power to the ground. Somehow he missed this massive difference due to the unavoidable daily 'terrestrial eclipse' e.g. night. Also he failed to consider social/political costs (securing land rights near where the power is needed, the ecological impact of killing millions of acres of vegetation etc) but he's good at ignoring that it appears, recall the HyperLoop plan.

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