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Towards a 50% Efficient Solar Cell
necro81 writes "IEEE Spectrum magazine has a feature article describing DARPA-funded work towards developing a solar cell that's 50% efficient, for a finished module that's 40% efficient — suitable for charging a soldier's gadgets in the field. Conventional silicon and thin-film PV tech can hit cell efficiencies of upwards of 20%, with finished modules hovering in the teens. Triple-junction cells can top 40%, but are expensive to produce and not practical in most applications. Current work by the Very High Efficiency Solar Cell program uses optics (dichroic films) to concentrate incoming sunlight by 20-200x, and split it into constituent spectra, which fall on many small solar cells of different chemistries, each tuned to maximize the conversion of different wavelengths."
There's basically two ways to get power in space. One involves plutonium, the other high efficiency solar cells.
Since launch costs are related to weight, anything that increases panel efficiency, even if expensive, is great
for solar applications.
Governments do not "invest", Governments move money from one place to another... VERY inefficiently.
How are Obama's solar investments doing? Oh, that's right, they taxed you... took your money, then gave it to some businessmen that promptly filed bankruptcy and drove off in their BMWs. Congrats.
In this list of recipients of the DOE's 1705 Loan program, 5 of out 26 are listed as being in serious financial difficulty, the majority of the projects on the list are on-track.
Direct costs of the war in Iraq were $800B, by the time all direct and indirect costs are accounted for (interest, injured and wounded, veteran care and pay), it could hit $4T. The Loan Program cost $34B (and that's only if all $34B loans are defaulted on).
So, for somewhere between 5% and 0.8% of the cost of war that we shouldn't have started, the US Government can help to move us toward alternative energy sources, and off of foreign oil (I know we have domestic sources for much of the oil we use, but since it's a global commodity, any oil we consume means more that volatile middle eastern states will sell)
I'm not sure that the vetting process for all companies is fair and balanced, but I do think it's a useful program.
So, for somewhere between 5% and 0.8% of the cost of war that we shouldn't have started, the US Government can help to move us toward alternative energy sources, and off of foreign oil...
This may become a reasonable argument when you find a way to ensure that spending on alternative energy sources (and other projects) comes instead of, rather than in addition to, the money wasted on war. The "balanced budget amendment" proposal would be a reasonable place to start. Until then, massive overspending in one area cannot possibly justify spending other areas, no matter how small the latter might be by comparison. Quite the opposite, really; when you're that far over budget to begin with, any additional spending requires more justification, not less.
"The state is that great fiction by which everyone tries to live at the expense of everyone else." - Bastiat
Is science just filled will bullshit these days? Here's an idea, instead dreaming of the 50% solar cellfor the year 2030, just focus on better manufacturing methods for the 20% cells? How about increasing the durability of the 20% cells?
Lets try the old car analogy... heck, it almost fits.
Instead of working hard toward developing more fuel efficient cars, we should have found better ways to manufacture the 60's vintage cars and continued to accept the 8mpg that was common then.
See how dumb that sounds?
What's wrong with research? It is after all what got solar from 5% efficiency to where it is today.
I'm not convinced its wise to build massive amounts of not-very-cost-effective solar installations when twice the capacity might be available in 5 years. (Finished and installed Solar is in the mid teens, not the laboratory figure of 20%).
Sig Battery depleted. Reverting to safe mode.
The simple fact is, whether anybody likes it or not, is that we simply haven't found ANY tech that can replace oil when it comes to the amount of energy per unit. Last I checked oil gives you a return of something like 30 to 1, most of the other techs are around 3-5 to 1. that isn't even close folks.
Then there is the problem of the NIMBYs, that frankly have a living shitfit if you do ANYTHING anywhere near them. Look at China, they are gonna have a good 25 nuclear reactors online in the time it takes the USA to get ONE through the 560 levels of paperwork and NIMBY bullshit. The smart way to go would be a combination of nuclear, molten salt and solar panels, wind and tide power generation cutting the living hell out of fossil fuel usage so pretty much the only thing we'd need it for is vehicles, but that will never happen here thanks to NIMBY.
Frankly I truly believe we could solve our energy problems within the next 15 years but sadly the whole damned thing has gotten too political. Instead of doing what will be best for the country you have lobbyists pushing blank checks for pointless programs like cap&trade, you've got NIMBYs having a shitfit if you build ANYTHING and the greenies are nearly as bad only they'll claim your new plant is gonna kill a frog or something. The whole damned thing here is so fucked up.
ACs don't waste your time replying, your posts are never seen by me.
Don't be a price snob, either.
If we wanted to go 100% solar for electricity generation over the next 50 years, it'd only take about as much as we're currently spending on federal government pensions. No small chunk of change, to be sure, but peanuts compared to the other big projects our society doesn't even bat an eye on.
(Assume $2 / watt installed, not much below the current bottom end but well above what such huge economies of scale would push it to. Assume 1 MWH per year per kW of panels, quite pessimistic -- I'm in Arizona, and I'm getting 2 MWH / year / kW, and Olympia, the dreariest part of the country, gets more than half the sun-hours we do here. Now plug in the Wikipedia figures for annual US electricity consumption, divide by 50, and compare with budget figures.)
Cheers,
b&
All but God can prove this sentence true.
It's not just solar, they are also very interested in wind, geothermal/ground source, and biofuels. But they think solar and wind have the most potential for their purposes (it's mostly only the Air Force interested in biofuels, for fueling their planes).
As for why, well, 80% of the convoys run in Iraq and Afghanistan are fuel convoys. On average, a soldier died or was wounded in one of every 46 of those convoys in 2010. And by the time you take into account the cost of the fuel and the expense of moving it, the military is paying something like 5-10 times the price you pay at the pump when you fill your gas tank.
What is this fuel used for? Some of it is used to power vehicles, of course, but the vast majority of it is used to provide electricity at remote and forward bases. They dump it in a generator, burn it, and wait for another convoy. On the other hand, the sun and the wind come to many of their locations without the need for a convoy.
The upshot of all of this is that with sufficient energy densities, the military could spend a whole lot more on solar panels and wind turbines that would seem justifiable to the average homeowner and still have it be economical -- I mean, just think of the money and lives that could be saved if a base could reduce the number of convoys it needs by 80%.
For all of that, you probably don't need cells with 50% efficiency, and I guess that's why TFA focuses on soldiers' gear instead of base power.
Your concern about a soldier contending with solar panels hanging off his back is a bit misplaced, I think. TFA says that at 50% efficiency, a 10-cm square panel is all that would be needed. That is already smaller than a single standard silicon cell in production today (standard is 15-cm square). And if you're worried about bad weather, sandstorms, and distractions then I would think that the last thing you want is a mechanical device with moving parts like foot pedals.