On Friday night(3/7/08) there was a show called EcoTech(can't remember the station:redface where they did a story on solar generation of electricity. They used solar collectors which resembled radio telescopes with mirrors that focused the light/heat on a Stirling Engine that was attached to a generator. The collectors were computer guided to track the sun all day long and could each generate 25KW. They threw out a figure that with 100 square miles of these collectors they could power the entire country. Now if they could come up with some good storage batteries the cloudy days could be dealt with.
As Tripp said, it's not new. It was one of the first ways used to get electricity from the sun, if you don't count hydroelectric (which is driven by the sun, but one order removed). Tom
As for storage, they're already doing that for nuclear power. It seems that nuclear is either on or off, with very little control in between. So they have a lot of excess nuclear power during the night. The solution in California is pumped storage. They fill up San Luis Reservoir during the night, and then recover the power as hydroelectric during the day. Probably terribly inefficient, but they have to send the power somewhere. There is a large need for sunny weather power production. Air conditioning in the southwest is a major power user, and that usage goes down when the sun isn't out.
Here is another along the same line. Suns heat to steam, steam runs a turbine and also runs a desalination plant to make drinking water from sea water. Wizard Power Pty Ltd - Solar Technology There is potential to store the heat for all day electricity. I'd love to see these along side existing coal fired power stations to replace the coal.
You can run the desalinization during the off-peak periods, since water is easy to store. That's a good solution in areas requiring desalinization. Tom
I still believe that it would be worth looking into individual storage battery facilities. Each business/household can install and maintain their own batteries to store, use, and distribute the electricity as it is needed. The batteries can be charged via the grid (or personal methods) during the off-peak hours or anytime more electricity is generated than used. If a person chooses, their batteries could be used to supply the grid in times of power shortages. To me, the ability to distribute the storage facilities is much less prone to overwhelming blackouts caused by attack, technological or natural disaster. And it should also be applied to the generation of the power as well: 100 square miles is merely two square miles per state, all connected through a mesh network of power distribution.
It is cheaper and easier to store heat than electricity. These thermal solar power plants store the heat during times of good sunshine then draw the heat off when there is darkness or cloud. This also means high and low consumption demands can be accommodated. The Australian system uses ammonia like a absorption system refrigerator, the ammonia is stored and used in a reactor ready to be circulated through the system again in the morning. I don't really understand how it works but it does. This method has no loss over time as the gas and liquid can be stores indefinitely. Not only is the electricity used to desalinate the water but the heat too.
Heat storage in molten salt is the way these things are going. The salts are Sodium Nitrate and Potassium Nitrate in a 60/40 ratio I think. The Denver Post just ran a cool article about it yesterday. Pat's right, much cheaper to store heat. It might also be more efficient, but I'm not engineer... Having these CSP plants with on site NG backup will become more prevalent in areas with lots of sunshine. It looks like a smallish plant is going to be built here in CO. The capacity will be something around 300 MW if IIRC.
And at least it's not all going to waste. Too bad there aren't hundreds of thousands of PHEVs to suck up all of that power. Pumped storage is probably the next best thing. At least they're doing that.
