Miles of pipes? Just aim them lenses at Hillary's arse... 
heat that big sucker up and it will take months for that large a mass to cool back down!
Posted on 04/20/2008 12:54:45 AM PDT by neverdem
Solar power, the holy grail of renewable energy, has always faced the problem of how to store the energy captured from the sun’s rays so that demand for electricity can be met at night or whenever the sun is not shining.
The difficulty is that electricity is hard to store. Batteries are not up to efficiently storing energy on a large scale. A different approach being tried by the solar power industry could eliminate the problem.
The idea is to capture the sun’s heat. Heat, unlike electric current, is something that industry knows how to store cost-effectively. For example, a coffee thermos and a laptop computer’s battery store about the same amount of energy, said John S. O’Donnell, executive vice president of a company in the solar thermal business, Ausra. The thermos costs about $5 and the laptop battery $150, he said, and “that’s why solar thermal is going to be the dominant form.”
Solar thermal systems are built to gather heat from the sun, boil water into steam, spin a turbine and make power, as existing solar thermal power plants do — but not immediately. The heat would be stored for hours or even days, like water behind a dam.
A plant that could store its output could pick the time to sell the production based on expected price, as wheat farmers and cattle ranchers do. Ausra, of Palo Alto, Calif., is making components for plants to which thermal storage could be added, if the cost were justified by higher prices after sunset or for production that could be realistically promised even if the weather forecast was iffy. Ausra uses Fresnel lenses, which have a short focal length but focus light intensely, to heat miles of black-painted pipe with a fluid inside.
A competitor a step behind in signing...
(Excerpt) Read more at nytimes.com ...
The solar tower plant outside Seville, Spain, can provide electricity for up to 6,000 homes.
Denis Doyle/Getty Images
Denis Doyle/Getty Images
If a thermos is good for storing heat, please explain why after I take the first cup of coffee the rest of the thermos goes cold quickly. My thermos is a good one, with one of those push-button tops that isn’t supposed to let out the heat. Hmmm....this whole thing sounds like wishful thinking.
New Rules For Food And Drugs Imports
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FReepmail me if you want on or off my health and science ping list.
Miles of pipes? Just aim them lenses at Hillary's arse... heat that big sucker up and it will take months for that large a mass to cool back down!
Because you let in cold air when you open it the first time.
IF these were designed for good efficiency, they would have a valve that would let out the hot liquid without letting in the cold air. Means that bottle would have to be pressurized to some extend, or it could not dispense completely
Not important for coffee, but critical for efficient energy storage.
It sounds better than subsidized, corn derived ethanol from fermentation and distillation. There's more than one way to skin a cat. Other than than the conversion infrastructure, solar power is a FReebie. One of the ways to stop the falling dollar is to stop importing energy. The U.S. should be energy self sufficient, and sell energy and energy harvesting technology abroad as a national strategy to defund our enemies and adversaries.
In 1980 a friend of the family heated his 3300 square foot home this way in Pennsylvania. In January/February he also used a woodstove with a hot water heat exchanger jacketed in the stove. About four hours of burn time stored all the heat he needed for cold, cloudy days in the worst of winter.
The largest demand comes from air conditioning units which are operating at the highest levels in hot climates, the same climates where solar thermal plants are placed. Reserve thermal capacity to sell after peek demand would simply ensure that the operator consistently missed the peak prices for his product.
The only feasible way I see this working is storing up thermal energy to operate the plant at high output during the early daylight hours before the system is fully up and running efficiently, thus providing a more consistent daytime output.
But really, if it’s hot and sunny enough to provide maximum output, it’s probably the best time to actually /be/ at maximum output.
That's enough energy to raise the temp of 1 liter of water by 50 C. OK. But is the converse true? Can you charge a 50 Wh battery with 1 liter of water 50 C above ambient? No! Not even close! A thermal engine running between 300C and 350C has maximum efficiency of 1/6, and this assumes an infinite reservoir of coffee at 350C. With a finite reservoir, the efficiency drops linearly as the thermal energy is depleted. Integrating, I get a result a little better than 1/2 the infinite reservoir value, so say 1/10.
To be fair, we may note that they want to use molten sodium as the storage medium, meaning that their "delta T" and hence efficiency of extraction is much greater. The lesson here is, their example sucks.
As to your observation, I think the answer is evaporation. The heat of fusion for water is 80 cal/g, so the evaporation of 1 gram of water is enough to cool 80 grams of water by 1 C.
Always complicating things.
Huge, expensive, inefficient facilities trying to store electrical energy as heat then converting it back, when a single flux capacitor can store and efficiently transfer 1.21 gigawatts.
Oh, by the way.
This company wants the CUSTOMER to pay more for THEIR solar power - at times more inconvenient for the customer - than with conventional energy sources.
I hope solar can be made to work economically. But it doesn't. Yet.
I have a pile of batteries I’m testing now for electrical bicycle packs... (They are actually the ‘antique’ LiCo chemistry, not the good new nanotechnology ones)
They average 5.03AH at (nominal) 3.6v.... I paid $11.34 each for a hundred.
Significantly less $ per watt hour than the ones you found.
A couple more years and lithium batteries will be even more efficient and cheaper.
Heat is as an inefficient store of energy as hydrogen.
Wouldn’t this, ahem, actually heat up the globe, if manufactured on a large scale?
I mean, we’re talking about making the earth a better heat-sink here.
~sigh. Iraq you' a$$clown isn't the reason your technology can't compete.
I support any method to generate energy that does NOT require, a subsidy, laws that force their usage, and are cost effective, and most important, kicks OPEC to the curb forever....!
Ha! That’s funny right there.
The reason why you think this sounds better is because you haven’t been around long enough, or you believe the hype of the solar advocates (who are the used car salesmen of the energy industry).
Here’s a little info for you:
http://www.nrel.gov/csp/troughnet/power_plant_data.html
Look at each plant’s “Special Incentives” section. Every one of them has tax benefits. Many (most) of the earliest plants had DOE money showered on them as well. Big bucks subsidies in some cases. Solar plants that are going to sell their power generations into California will enjoy very tidy ongoing subsidies through California’s renewable energy power purchase tariffs.
Now let’s talk about efficiency. The typical heat-capture solar plant shoots for an efficiency of about 12 to 14%, usually achieves something less than 10%. The very latest PV technology has finally broken the 40% return barrier, but will take years to commercialize. Today’s typical PV cells have a solar efficiency of about 8 to 18%.
The aggregate estimates for the return on ethanol are about 30%.
You’re getting more bang for your subsidy buck with ethanol today.
Thermal mass is a better idea and it's been around a long time. Folks just don't use it much.
A friend of mine had a house in Colorado that had a thermal mass tank in the basement with solar collectors on the roof. The house was located at 10,100' msl with some south exposure and the system, although completely homemade, worked beautifully. The tank was simple concrete block construction with a plastic liner and it held about 1800 gallons of water. Heat exchangers, made from copper pipe, circulated hot water by way of a small pump from the collectors to inside the tank where the tank water absorbed the heat and stored it. Typically, the tank would stay at about 150F-170F, even in the dead of winter. The tank was well insulated and he could heat his home all but about 3 weeks a winter on sun power alone using radiant baseboard heaters. Radiant floor heat, as I have in my home, would have worked even better. He also had a loop going to a wood fired stove that could heat the water during extended cloudy periods, but he rarely used it.
If you added river rock to the tank to add additional mass, it would work even better. There really is no need for the added complexity of this thermos addition.
The concept is valid. The idea is good. Turning the idea into a practical means of storing the sun’s energy for use at night is worth pursuing.
The skepticism expressed by some posters shows ignorance.
For American business, anything "works economically" if it attracts a government subsidy.
One of the "magic" heat storage mediums for solar back in the 70's was Glauber salts.
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