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Large Scale 24/7 Solar Power Plant To Be Built in Nevada
RayTomes writes "The Obama administration has provided a loan guarantee of $737 million to construct the first large-scale solar power plant that stores energy and provides electricity 24 hours a day, 7 days a week."
This solar power project, a heliostat rather than a photovoltaic system, with a molten salt system to store power as heat for times when the sun isn't shining, will be constructed in Nevada and, says the article, is expected to create "600 construction jobs and 45 permanent positions."
So the plant is suppose to produce 480,000 MWh per year which works out to an average capacity of 55 MW. So we get 0.8 permanent employees per MW. http://www.tonopahsolar.com/
At slashdot's favorite nuclear power plant Vermont Yankee, there are more that 650 employees for a plant that does not manage to run at 620 MW all that well. Let's give them 80% up time. That is 1.3 employees per MW.
Nuclear power seems less efficient than solar power by this measure. Maybe nuclear power is just a "make work" type jobs program which actually hurts the economy overall.
I 'm not certain about the numbers involved, but I'm happy to see the government doing what I believe it should: promoting things that are good for us that we wouldn't otherwise get. By that I mean buffering the long-term payoff on things that cost too much for the market to provide now.
This will use a combined solar thermal collector/salt storage, powering a thermal engine. Not a problem. However, what that does is use the solar thermal to heat the storage and then power it all nightlong. So, for example, if you want a 100 MW output 24x7, you will need 300-400 MW tower (a lot more money). Not an issue. BUT, the storage is what is important. It would be better for the companies going into this, to split out the storage portion and make it distributed. In particular, America has a large number of OLD coal-based power plants that are going to go away over the next 20-30 years. Many of these are currently inside of cities. They are typically 50-100 MW in size (which was large monsters in the day). They have power lines that emanate from them. They also have cooling plants (typically, water), combined with steam engines/generators. But all that is really needed to be changed is that piping re-upped, and the coal boiler dropped. Instead, put in a high temp salt storage system, and use electricity to bring the temp up. With this approach, you can have a large CHEAP battery. The argument against it will be the inefficiency of it. There will be a loss of energy of roughly 50%. However, current tech with CASE, Hydro, batteries, etc. all have losses of 20-40% or so, but have many drawbacks. Hydro and Case can only be used in certain areas and are expensive. Batteries are VERY expensive to install, though they have the advantage of going anywhere.
In the end, the question should not be how efficient it is, but how economical it is. A thermal storage that has little costs to set-up, but will last for 20-30 years (within 10-15 years, ultra-caps will become the dominant form of new storage, and would then replace this). That approach extends this equipment for very little costs. More importantly, it would enable ALL FORMS of Alternative Energy to provide power as they can, since the salt storage would act as a buffer for demand systems. Right now, America loses something like 12 GW yearly because they have to feather wind generators at night. Likewise, we have gas turbine generator that are built to handle the demand, esp. when AE falls. With a thermal storage, it provide our demand system, while allowing AE to run at full power.
I prefer the "u" in honour as it seems to be missing these days.
Granted - in Nevada they will need to ship lots of water out to the plant to keep the mirrors clean. But its still cheaper than coal or oil. But it won't be subject in any meaningful way to the whims of the coal or oil markets.