Cheap, Superefficient Solar

Cheap, Superefficient Solar

"Solar-power modules that concentrate the power of the sun are becoming more viable.

Technologies collectively known as concentrating photovoltaics are starting to enjoy their day in the sun, thanks to advances in solar cells, which absorb light and convert it into electricity, and the mirror- or lens-based concentrator systems that focus light on them. The technology could soon make solar power as cheap as electricity from the grid.

The idea of concentrating sunlight to reduce the size of solar cells--and therefore to cut costs--has been around for decades. But interest in the technology has picked up in the past year. Last month, Japanese electronics giant Sharp Corporation showed off its new system for focusing sunlight with a fresnel lens (like the one used in lighthouses) onto superefficient solar cells, which are about twice as efficient as conventional silicon cells. Other companies, such as SolFocus, based in Palo Alto, CA, and Energy Innovations, based in Pasadena, CA, are rolling out new concentrators. And the company that supplied the long-lived photovoltaic cells for the Mars rovers, Boeing subsidiary Spectrolab, based in Sylmar, CA, is supplying more than a million cells for concentrator projects, including one in Australia that will generate enough power for 3,500 homes."

http://www.technologyreview.com/read_article.aspx?id=17774&ch=energy

I would add that I read a story several months ago about Universty research into solar cells (I forget which school.) They had developed an infrared solar panel that will use the heat energy from the sun to generate electricity. I believe the article mentioned the possibility of solar cells that use this new technology plus existing types to harvest as much as 35% of the total solar energy falling on the panels.

Makes me think I should hold off for another year or two before I install these on my next house. At that efficiency level, solar will trump most centrally produced energy alternatives.

'Off-the-grid' is becoming more and more practical every day. :thumbsup:

A lot of solar technology is sitting on the shelf because government policy under Republicans and Democrats has directed massive subsidies to competing energy sources, such as nuclear, coal and oil, making it difficult for solar and wind to compete because the playing field is not level. Dr. Lewis Fraas, a former top scientist for Boeing, builds super efficient solar panels using mirrors and telescope technologies. In the solar panel Dr. Fraas is standing behind, he replaced some of the expensive PV crystals with inexpensive mirrors. With the mirrors, each PV crystal sees the equivalent energy of 3 suns, making more energy will fewer silicone PV cells. This is a cheap technology advance that China has purchased (long-ter costs of 8 cents/kWh). Dr. Fraas also has a cassegrainian model that uses telescope technology to focus the equivalent of 500 suns on each solar panel.

But even back in the 1980s, Dr. Fraas invented a super efficient solar panel that is able to convert both visible-light radiation and infrared radiation into electricity. The sun's energy at noon is about 970 watts per square meter. About half that energy (490 watts) comes from visible light, which is what today's solar panels (Photovoltaic, or PV panels) use. The rest of that energy is mostly infrared energy that can be captured with Thermophotovoltaic (TPV) cells made out of gallium antimonide (GaSb). Dr. Fraas makes a panel with PV cells on top and TPV cells underneath, allowing it to capture energy from both the visible and infrared spectrum and making it 35 percent (340 watts per square meter) efficient. Most PV cells today are between 6 percent and 15 percent efficient, although Sunpower makes a 20 percent efficient PV cell. The photo with Dr. Fraas and the lamp is simply a candle flame surrounded by GaSb crystals that convert the heat to electricity and run a small radio.

If this country ever gets serious about energy policy, we will find the solution to both cheap energy and environmentally responsible energy is right under our noses.

If we want to get serious about saving energy - how about a legal requirement through the "sunbelt" that any new construction or major renovation MUST include solar water heaters on the roof? It's amazing how much energy is used keeping a tankful of water hot and ready for use. Solar water heaters are low-tech, "mature" designs, and cheap considering how much energy they can save.

Yup.

We have many technologies ready to deploy. Time to wake up America, start getting off of fossil fuels. There are several thin film solar panel companies poised to provide really cheap solar electric panels for our homes.

We'll need standard grid interconnect equipment to mass produce at low prices and national standards for that interconnect and national policies requiring the grid monopoly utilities to make "home generated electricity interconnect" simple, easy and cheap.

:bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow:

if this new stuff is anywhere close why are regular solar panels still so expensive..?
this place http://www.nanosolar.com/ is about to produce "regular" tech panels but on a much cheaper mass-production basis in California..
I wonder whose new technology will be available first..?

which solar hot water system do you recommend?

I've changed over to primary wood heating for entire house. I'd get off gas grid completely if I could. don't know about your part of country, but our prices have gone up by 3x-4x. absolute gouging!

Biker Bear said:

If we want to get serious about saving energy - how about a legal requirement through the "sunbelt" that any new construction or major renovation MUST include solar water heaters on the roof? It's amazing how much energy is used keeping a tankful of water hot and ready for use. Solar water heaters are low-tech, "mature" designs, and cheap considering how much energy they can save.

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TedTheLed said:

if this new stuff is anywhere close why are regular solar panels still so expensive..?

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Lots of small R&D companies or a scientists come up with a new, cheaper solutions, but they still have to go through qualification trials to become eligible for subsidy programs, like those in California. But those trials can cost millions or tens of millions of dollars or more. Small companies can't afford it, so their panels are not eligible for subsidy programs and so no one is going to buy them. China is buying these technologies, but not the US. And a lot of the big solar companies -- BP and Shell -- are oil companies that get one zillionth of their income from their solar business, so they have no incentive for innovation, but they can still undercut independent companies on price so the solar industry's growth is held back.

cy said:

which solar hot water system do you recommend?

I've changed over to primary wood heating for entire house. I'd get off gas grid completely if I could.

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One easier step, if you have gas, is to switch from a conventional water heater to a tankless gas hot water heater. You'll save about $250 a year if you use the typical amount of hot water, and you'll pay for the heater in maybe 3 years. Plus, this heating system can be plugged into a solar-hot water heating system as a back up on cold, cloudy days. And because you have no hot-water tank, you never run out of hot water.

Natural Gas heating still seems pretty inexspensive in my area but I guess it depends on what you do with it. We mostly use it for cooking and hot water. Cooking dosen't seem to use too much gas and my water heater, although 16 years old now, actually has some very thick insulation built in. I rarely hear the burner operating unless it's just right after someone using the shower or other hot water faucet. There's also the clothes dryer but I do laundry mostly on the weekends and it probably drys 4-5 loads. I don't run the furnace unless it is raining and/or the temperature outside dips below 55 F.

Using electric heating in my area is more expensive. I'll have to compare my bills with people I know who have and electric range and clothes dryer to figure out the increase though.


Speaking of solar power (and other renewable sources), I'm still waiting for the price of solar panels to come down as well. I've been looking at obtaining some of the Siemens (Shell) Copper Indium DiSelenide (CIdiS) Thin Film cells for a while due to the efficiency (around 13% I heard, but comparable to a polycrystaline cell) and low production costs but they suddenly stopped producing them for some reason.

I already have a SLA battery and 12 volt wiring with cigarette lighter sockets and Anderson PowerPole connectors for outlets in my room. All it needs is just a charge controller and a panel.

TedTheLed said:

if this new stuff is anywhere close why are regular solar panels still so expensive..?
this place http://www.nanosolar.com/ is about to produce "regular" tech panels but on a much cheaper mass-production basis in California..
I wonder whose new technology will be available first..?

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Because they still cost a lot to build. It's only been recently that the solar cell has gone positive in terms of energy cost, that is, they used to use more energy to produce than they produced over their life time.

I don't see any great advantage using mirrors and lens. They will remain expensive and things like rain and dirt will always reduce efficency.
If you want mirrors build a big array (a few acres worth) and boil water.

Another tact that has been examined is arrays under water or brine solutions. They are almost as efficent and the heat collected by the ponds can be used for other heating needs.

Look up "solar cell ink jet" for a less efficent but very cheap method of production.

"gone positive" ? why judge them this way, and not other tools, like cars? or houses? if you are translating the tools efficiency into money, and say the car aids in the production of money (to get yoy to work etc.) you must take into account the over all effect of using solar panels over oil..the costs of pollution and war on human health and the vitality of the planet..
it's difficult to say the least to quantify "production" in a tools lifetime, or a person's for that matter..besides I figure a 75 watt panel that cost $350 each when I bought mine, even figuring at 10 cents a kilowatt hour, (artificially cheap imo) will produce it's own monetary cost in electricity in less than twenty years (at 7 hours a day sunshine..) -- and it will continue to produce beyond that point.

cy said:

which solar hot water system do you recommend?

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I installed a system from Solarroofs.com in June. My overall eletric bill (all electric house) was down about 20-25% comparied to last year for the last couple of months.
Of course you have to be careful, the solar stuff can be worse than flashlights in that you always want to improve($), monitor performance($$), improve($$$), etc.

TedTheLed said:

"gone positive" ? why judge them this way, and not other tools, like cars? or houses? if you are translating the tools efficiency into money, and say the car aids in the production of money (to get yoy to work etc.) you must take into account the over all effect of using solar panels over oil..the costs of pollution and war on human health and the vitality of the planet..
it's difficult to say the least to quantify "production" in a tools lifetime, or a person's for that matter..besides I figure a 75 watt panel that cost $350 each when I bought mine, even figuring at 10 cents a kilowatt hour, (artificially cheap imo) will produce it's own monetary cost in electricity in less than twenty years (at 7 hours a day sunshine..) -- and it will continue to produce beyond that point.

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If it costs 100 gallons of oil to produce something that will, over it's entire life span, produce the equivilant of 70 gallons of oil, then there is a net loss.

You save no energy and that is the issue, not how many dollars it costs.

Josey said:

One easier step, if you have gas, is to switch from a conventional water heater to a tankless gas hot water heater. You'll save about $250 a year if you use the typical amount of hot water, and you'll pay for the heater in maybe 3 years. Plus, this heating system can be plugged into a solar-hot water heating system as a back up on cold, cloudy days. And because you have no hot-water tank, you never run out of hot water.

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Three years sounds a bit optomistic. In any event be aware that if these units are not sized properly and you have a family, it may be fun.
You can wash dishes OR take a single shower OR wash clothes and those are exclusive "OR"s.

Mike, it's not only whether or not you save energy-- (and I pointed out that you do with a solar panel, with the value of electricity figerred at only 10cents a kwh! just double that to 20cents and you start coming out way further ahead..and the price per kwh is a lot higher than that in many places..) -- but how you save energy. The idea is to avoid using oil. Eventually, solar panels could beget solar panels.. at the present state of panel technology a panel 70 miles on each side could supply all the US electrical needs..

Mike Painter said:

If it costs 100 gallons of oil to produce something that will, over it's entire life span, produce the equivilant of 70 gallons of oil, then there is a net loss.

You save no energy and that is the issue, not how many dollars it costs.

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Are you aware of any such solar technologies?

The numbers I've seen is that solar panels pay back their creation energy in 3-5 years.

re: tankless heaters; you can get over 5 gallons a minute of up to 180 degree F (!!) water out of these units (that's what the idiot plumber set mine at when he installed it wrong.) ..mix that down with cold water and you can shower, wash clothes, and dishes simultaneously.. check out Tagaki.

metalhed said:

I would add that I read a story several months ago about Universty research into solar cells (I forget which school.) They had developed an infrared solar panel that will use the heat energy from the sun to generate electricity. I believe the article mentioned the possibility of solar cells that use this new technology plus existing types to harvest as much as 35% of the total solar energy falling on the panels.

Makes me think I should hold off for another year or two before I install these on my next house. At that efficiency level, solar will trump most centrally produced energy alternatives.

'Off-the-grid' is becoming more and more practical every day. :thumbsup:

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Using a small portion of the IR is a great idea, it should help with the global warming problems caused by solar farms, which cause temperatures in the area to typically heat up 5 to 7 degrees. The extra absorbed energy should help reduce this by a degree or two.

Wonderful idea to fix some of the drawbacks of solar cells!

Now if they could just harness the other 65%, and it would lower the local temperatures, and reduce the effect on global warming.