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DARPA Awards $53 Million for Solar Power Research
mygadgetbox writes "Defense Advanced Research Projects Agency (DARPA) will be giving a consortium led by the University of Delaware nearly $53 million in funding to more than double the efficiency of terrestrial solar cells within the next 50 months. DARPA wants the consortium to develop and produce 1,000 Very High Efficiency Solar Cell (VHESC) prototypes that are affordable and that operate at efficiencies of at least 50 percent. The goal is to create solar cells that operate at about 54 percent efficiency in the laboratory and 50 percent in production."
Not true. ROI is about 18 months. Expected lifetime is upwards of 15 years.
If we are talking about traditional p-n type solarcells, they physically can't do better than ~37% IIRC. There is just no way to avoid some (alot!) charge recombination. In addition there is a lot of solar energy that is not within the absorption curve. I really hate it when people throw numbers around without a reference. All photovoltaics should be referenced to AM 1.5 (the typical energy that reaches the earth). The solar people all talk about photosynthesis as 'near 50%' but that is only over the narrow absorption range of the special pair and does not include any further electron transfer steps. I have to concur that it is all about making them cheaper. That said, while you can trade effiency for cost, the who 'nanocrystal photovoltaics' died a quite death cause the charge transfer was just SO piss poor due to it being an amorphous device. Now if someone can figure out how to add some structure (chemical self assembly) then you might have something. As with most other hyped science I would not hold your breath. Engineers are damn cleaver people and my bet is on the thin film amorphous silicon and cadmium telleuride ribbons being developed. solarcell
Solar cells are not now, and will not in any near term (5-10 years) be a method for general electrical energy generation.
Generating electric energy with solar cells is a great idea, but they are still a speciality, because the price of the cells are so high. Prices are falling, and have been doing so for many years, but they still have a long way to go to be competitive to other large scale energy sources.
Solar cells needs more researching and funding for R&D. It will be great once it becomes affordable. Until then it is only a niche energy source for use in special locations and applcations.
For the time being the are luckily other sources for large scale non-polluting energy production, namely electrical energy from wind power. Wind power is a proven technology that is readily available and can be installed for large scale usage. It also has the benefit of being a decentralised, scaleable technology (start small then scale up).
The installed capacity for wind energy is like 20 times larger than solar power. In 2002 the world wide capacity for wind power was 32.0 GW, for solar cells it was 1.3GW. Numbers are from report by BP (the oil/energy company).
In many countries wind power is the fastest growing energy source. In Denmark 19% of electric energy is made by windmills. In Spain it is 6%, in Germany 5%. In actual numbers for installed capacity Germany is by far the leader in the field, then followed by Spain and USA. See ewea.org and gwec.net site for further numbers.
While most European countries are racing ahead and installing windmills on land and in the sea, not much progress has been done in USA in recent years. This is especially sad due to the population size of USA and the high energy usage per person.
I'd suspect he's referring to parmalot or some equivalent. That's treated milk, which doesn't go bad at room temperature as long as the carton is sealed. It is very popular in many other countries (eg the Philippines) when refrigeration is a problem. It comes in many different sized cartons, so that you can open only about as much as you need.
I have two solar powered businesses here (a computer consultancy, and a machine/plating shop), and two homes which run off the same systems. Square feet definitely matter, as I am nearly out of useful roof space now. The 1000 sq foot building that has the machine tools is covered, and could use twice what I have now (although with a 2kw array, it could also be worse - 8-10 kWh a day ain't bad). I've got room for one more rack of 4 panels (about 500w more in full sun). A 500 sq foot building has its roof completely covered as well, and usually I have to pump power from the larger system over there to back it up when things aren't ideal. Any well designed solar system has the problem of, well, February...The Solarex polycrystalline panels I have on both places (2 of the four buildings that aren't always in shade) do the best in "non full sun" or gray days of all the types and brands I've tried, and this MATTERS in real life, bigtime. Getting half or even a quarter of the full sun output is far better than nothing, for example, and there are times when one either lives on this or burns petroleum in a generator, which is very expensive. But employees expect to work and get paid no matter the weather, so one copes. Remember that lead acid batteries have lousy efficiency, down to 40%, so the generator or panels lose a lot there if you're not using the energy as it comes in. There is simply not enough room on the average building around here (SW VA) to handle the bad weather months. This is a system that can run air conditioning and BIG multi HP power tools on good days...and barely limps by on nightlights if we have a week of near darkness, which happens often enough.
True, but since you are getting it "for free" from the sun, a certain amount of inefficiency is tolerable. The lossage can be minimized by transmitting the power on the right frequencies.
It would also need to be very precisely targeted - at those sort of distances, a fraction of a degree off could result in blasting some poor shmucks house of the face of the earth
There are several simple ways to deal with that problem:
So the problems you mention are solvable IMHO. The real showstopper, for the moment, is getting the solar arrays into orbit: our current rockets have nowhere near the amount of lifting capacity required to make the economics practical. Possible solutions for this problem might be making the solar arrays on the moon, or (my personal favorite) the Space Elevator, which would make it practical to lift large amounts of mass to GEO.
I don't care if it's 90,000 hectares. That lake was not my doing.
It is in use all over the place here in Australia. Not along every main road, but it is used where there is no easy access to mains electricity. A location in the middle of a park, or on an isolated country road easily justifies solar power.
In my former job working on road transport systems we frequently installed solar and wireless traffic monitoring systems and emergency telephones.
You save on trenching this way, and also on maintenance because underground cables are forever being dug up by people.
http://michaelsmith.id.au