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Efficient Solar Power Using Stirling Engines
tscola writes "The EE Times is reporting that the U.S. Energy department believes it can make solar collectors that generate electricity at efficiency levels that rival other methods. Instead of using photovoltaics, they want to use Stirling engines to convert the heat of the sun into electricity."
> Why so big scale?
Why not make it easy for everyone to have in his home?
Simple: It would be more difficult to tax.
Any reason why not?
Assuming that the guys designing this stuff aren't total idiots, rest assured that they looked into something like your proposal. Apparently they came to the solution that using grid power and software to control the staggered startup is cheaper than adding a battery to each dish.
Na, that just adds to the cost when having to purchase extra dishs. A better idea would to have just ONE dish pull from the grid to start up. Then, have all the other dishes start up from that first dish. Simple yet effective :)
Life is not for the lazy.
[blockquote][i]By storing the energy in hydrogen fuel cells during the day, Stirling solar-dish farms could supply U.S. electrical-energy needs at night too, as well as enough juice for future fuel-cell-powered automobiles, the DOE believes.[/i][/blockquote]
So, they're arguing around the limitations of the system by promising another completely different undeveloped system? I call bullshit.
If you wanted to store energy, the best way that's actually developed and in use would be to pump water up into a reservior, then run hydroelectic generators during peak usage. Especially since the motion of a Stirling engine is well suited to running a piston pump.
Jon Acheson
All opinions expressed herein are my own, and not those of my employers, who are appalled.
You have to figure the cost of the real estate these items sit on, versus what other purposes the land could be used for.
In the case of other power technologies, the land use is relatively concentrated. Mines, transport routes, powerplants, refineries, etc. don't take up nearly as much space.
If the corporations profiting from fossil fuels were required to pay the real estate costs for the production of their products then solar would come out way ahead.
Hundreds of miles of streams have been burried by mountaintop removal/valley fill coal mining (no charge) -- Thousands of acres of lakes and rivers mangled by acid rain (no charge) -- Millions of acres of forests damaged by acid rain (no charge) -- Thousands of miles of streams and millions of acres of ocean polluted with mercury (no charge) -- All the air on the planet altered in compostion by CO2 exaust with unpredictable consequences (no charge)
They get away with it because we let them. We want "cheap" energy but we only get it by ignoring the real costs.
- Hail to our fearless misleader! Fool speed ahead!
- Adding a battery doesn't eliminate the need for software to control array startup to prevent swamping the various control and distribution systems within the array, as well as to prevent causing problems with the grid the array is attached to.
- Adding a battery (and it's associated charging and monitoring equipment/software) increases the capital and maintenance costs of the system without providing significant benefit. (See reason 1.)
That being said; If I were designing/specifying/building/buying such an array, I'd have one or two dishes that could started via the control centers backup power supplies. Those dishes could then be used to 'bootstrap' the remainder of the array.Oh, and where do you suggest we get this "tar" to make gasoline from? Do you even know how we make tar?
If all this should have a reason, we would be the last to know.
Remembering that the actual heat isn't going very far, the cooling isn't *that* interesting.
.5 to 2 times the size of the farm. The thermal might cast a rain shadow but not for more than twice (?) the length of the chord distance that the prevailing wind passes over the farm.
We arn't reflecting the heat off into space (a la snow-cover), we are reflecting it to a heat sink about 20 feet off the ground.
The heat passes through that heat-sink and into the air. The air temprature will probably *rise* during the day because the ground isn't soaking it up _directly_. Any given square-inch of ground will be in shdow for about two extra hours a day per dish (wild-ass geuss from just looking at the thing) and will be subject to the shadows of three dishes max. So any given square inch will be "shaded" for half the day.
A good bit of that heat will get back into the ground anyway.
The net environmental impact would be about the same as for sparse tree cover (But without the water use and with a dissimilar habatat provision).
Soil water retention would go up just a tiny bit.
The most liekly impact woudl be changes in midle-size air masses within a range of about
So worst case, (total wog again here) about the same climatological impact as if say one-third the same area were covered with "water that couldn't evaporate" or concrete sculptures of trees.
A similar area covered with buildings would probably be worse in general. It would be the classic "downtown effect" (where it is hotter downtown during the day and colder downtown at night).
Innocent people shouldn't be forced to pay for inferior software development.
--"Code Complete" Microsoft Press