But those aren’t suitable for thermal storage, so I’m not sure they are going to be long-term winners for utility scale generation. And they are too big for homes.

That said, if you want some solar thermal, you can get a water heater on your home (I have one) and in most parts of the country, this will have a good payback — especially if you’re old water heater need for placement or you are doing any new construction.

One comment I have about the Salon article… you imply that the water problem is a non-issue by stating that air cooling can be used. While true that air cooling can be used that is also true of any other power generating technology from coal to nuclear. The caveat is that air cooling increases capital costs and/or reduces efficiencies. Therefore the cost estimates for cents/kWh that you give would likely not hold for air cooled systems… I assume. A more complete coverage of this issue would be helpful.

Also, it would seem that the U.S. regulatory system favors local generation over long distance transmission. In addition to mechanisms such as tax credits and loan guarantees, are there regulatory or structural issues that must be addressed to enable the free flow of electricity on a country wide scale?

The government helped give us the railroad system, highway system, and the Internet. They are going to have to give us a HVDC system that connects to wind in the midwest and CSP in the SW.

http://www.energyfromthorium.com/ppt/thoriumPotential.ppt

especially slide 11.

CSP is commercial now, and will beat $.10 a kilowatt hour within 5 years.

The “nuclear” option is often dismissed on sites like these because they are fixed on the light-water reactor paradigm. So they get in the mode of saying things like “we can’t build them fast enough” or “we’ll have to build 10 Yucca Mountains” or “we’ll run out of uranium in 50 years anyway”. Those statements might be true for light-water reactors, but not for liquid-fluoride thorium reactors.

This reactor type went from an idea to a demonstration in 3 years in the 1950s, when we had practically no nuclear modeling capability like we do now. It doesn’t require large forged pressure vessels or huge containments. It get much better efficiency than LWRs and uses a tiny fraction of the resources. It can be built fast and super-safe, because the safety features are inherent to the design, not engineered in later like LWRs. Engineered safety can fail, inherent safety is immutable. This reactor CAN stop global warming AND lift the world’s standard of living at the same time. That’s worth working on.

http://peswiki.com/ index.php/ Directory:Geothermal_Oil_Wells

Traditional air cooling technology involves fans to drive sufficient air flow as an alternative to cooling towers. The primary problem with this is that it becomes inefficient on very hot days. This has led to what is sometimes called “hybrid cooling”: using air cooling most of the time, and wet cooling when air cooling becomes too inefficient. You can find out more in the EPRI Journal.

To get to paying perhaps $.10/kWh we have to start deploying this technology at a somewhat higher cost. The $.10 kWh for a fossil fuel replacement plant with storage is with 98% probability not going to just pop out of a laboratory but will come from economies of scale in manufacturing and construction. If Americans want to get a leg up on this they should be willing to pay somewhat more now to start catching up to the Spanish. Abengoa in its literature puts the crossover point for cost of CSP over natural gas plants at about 2018. But if we sit on our hands at higher per/kWH costs, we won’t get these deployed in time or remain dependent on countries (Spain primarily) with better renewable energy support structures to do the heavy lifting.

source:

cohesion.rice.edu/CentersAndInst/CNST/emplibrary/Hartley%2004May03%20NanoTechConf.ppt

see also

http://www.abb.com/ cawp/ GAD02181/ C1256D71001E0037C125683200658E0C.aspx

a) They’re clearly well beyond Research into development and Deployment, which is when something can get big enough to generate big $$.

b) They don’t depend on anything exotic in terms of materials or manufacturing. Although there’s plenty of sand on the planet, we’ve seen temporary impediments like insufficient supplies of solar-grade silicon hold PV back. But, it takes a while to build the factories to create that silicon. Still, CSP & windmills don’t need any of that, and I suspect there are a bunch of automobile-industry military-industry supplies who have useful capacity. one wonders, for example:

1 Abrams M1 tank & fuel it uses over its life = ?? CSP or windmills?

c) I’ve looked for home-size CSP with no luck, definitely hard to scale down, like wind turbines, although I’ve seen several companies trying that. We have too many trees around us for the latter, for sure.

d) For solar & home, besides solar hot water and solar PV (where that works), and just doing better insulation [we just put in some more thermal blinds over the big plate glass windows, and they really help], if I had a wish it would be for really smart window systems:

windows that are solar cells when then can be, reflective when they need to be, maybe with electrically-controlled blinds if needed, run by wireless sensor nets (temperature, light) that talk to programmable thermostats. Most of these pieces exist in some form or other, although I haven’t seen them all together.

Anyway: Joe, have you any thoughts on windows in the built environment? and how much effieicny can be gained? [We’re working on local codes, so this is of broader interest.]

Also note that Stirling Energy Systems’ webpage already says the cost is less than 10 cents per kWh.

NREL’s estimates are that we should see 7 cents per kWh around 2010 and 5 cents per kWh around 2020. These estimates pre-date the rapid rise in commodity prices, but CSP is pretty low-tech, and may be less affected (Ausra likens their materials to Farm equipment).

http://www.sopogy.com/

Re: costs…don’t believe all you read. I’ll leave it at that.

Earl: I think “more valuable” is a little imprecise, i.e., it’s certainly true in CA right now by $, i.e., daylight power costs more than night power

But, I think windpower might be “more valuable” in the long term, in the sense that:

a) At least in CA and the Southwest, there’s enough sunlight for all the daylight power we need, given big CSP farms + PV for micro-scale help. Certainly some of the CSPs can do storage, and if someone invents really great batteries, we’d be done.

b) For baseload, though it seems like we could use a lot of windpower, given that big distributed windfarms can do that. See Prof. Jacobson’s page at Stanford (a lot of good stuff):

http://www.stanford.edu/group/efmh/jacobson/

and specifically, under I. b:

Cristina L. Archer and Mark Z. Jacobson, “Supplying baseload power and reducing transmission requirements by interconnectiing windfarms.” 2007.

http://www.stanford.edu/ group/ efmh/ winds/ aj07_jamc.pdf

Windmills seem like a bigger part of the solution outside the sunny Southwest, i.e., where they “lack” nice empty deserts. I especially like putting windmills on farmland, a nice dual-use.

I also recommend Mark’s testimony on April 9 to the US House of Representatives:

http://www.stanford.edu/ group/ efmh/ jacobson/ 040908_testimony.htm

“I will discuss the scientific findings on the effects of carbon dioxide, emitted during fossil-fuel combustion in California, the U.S. and the world, on air pollution and health in California relative to the U.S.”

See “Results from the studies and analyses are as follows:”

basically, more CO2 hurts CA health worse than it hurts most states.

http://www.popsci.com/ environment/ article/ 2008-02/ shocker-worlds-largest-solar-plant-use-solar-panels

The article said something about the need to keep the CPV at or below 60 degrees C at least for the metal holding the thing together.

Maybe they could make a hybrid out of these things.

First heating: CPV for the first heating of the water to get the water temp to 60 C.

Second heating: The rest of the heating with the Ausra cheaper system.

Third heating: With the more expensive system that Lutz and the Dept. of Energy developed in the 1980’s.

The thing I was wondering about with the Ausra system was the low water/steam temp they were using. Any increase in operating temps helps in the Carnot cycle.

If they could get electrical power out of the CPV, maybe that would help with their efficiencies and costs.

I am sure that additional advances will be made, but only 3% still seems a futuristic projection to me.

For land use, a wind farm takes approximately 8 times the land area as a CSP farm of the same energy output, but since only 5% of the wind farm area is occupied by the turbines, that means the land displaced is about 60% less than a CSP farm.

http://www.actewagl.com.au/Faqs/WindFarm.aspx
says 2%.

http://www.wel.co.nz/index.asp?pageID=2145843299 says 2-3%.

I think this is the difference between the footprint of the blades and the (smaller) footprint of the towers, plus roads, transformers, etc.

http://www.ucsusa.org/ clean_energy/ renewable_energy_basics/ farming-the-wind-wind-power-and-agriculture.html
has a good picture , with crops planted right up (close to) the base, since the baldes are normally high enough for tractors to pass underneath with no trouble.

How much land is needed for a utility-scale wind plant?

In open, flat terrain, a utility-scale wind plant will require about 60 acres per megawatt of installed capacity. However, only 5% (3 acres) or less of this area is actually occupied by turbines, access roads, and other equipment–95% remains free for other compatible uses such as farming or ranching. In California, Minnesota, Texas, and elsewhere, wind energy provides rural landowners and farmers with a supplementary source of income through leasing and royalty arrangements with wind power developers.

A wind plant located on a ridgeline in hilly terrain will require much less space, as little as two acres per megawatt.

http://www.flodesignwindturbine.org/cms/

It remains to be seen, but this is a spinoff of some serious aeronautical engineering folks with a good customer list. Of course, one must always apply the cautions in:

http://www.wind-works.org/ articles/ FantasyWindTurbines.html

Anyway, both CSP and wind turbines have a lot of merit.

www.desertec.org
www.trec-uk.org.uk
www.gezen.nl
www.trec-france.org

www.solarpower-home.com