So I attended a lecture today on the state of the industry when it comes to solar power. The results were very interesting, and pretty non-biased, so I thought I'd post them ON THE INTARWEBS!!!
For everyone who's not in the know, solar power has two big problems: the construction expense, and storing energy during non-peak power times. The first one is pretty understandable: it's expensive to create mirrors, or photo-voltaic cells, and so on, which means that the power that comes from those plants has to be expensive to justify their operation. It's also a big cost out front for companies to foot, hoping for future profits, so development isn't as fast as many would like, and what does get constructed usually doesn't put out enough power to be a significant factor in a city's infrastructure.
The second is a little harder to comprehend. The power demand for a city varies with the time of day pretty substantially, so the power companies have to be able to deliver a lot of power at certain times of the day, and less power late into the night. With traditional power plants, you just start burning more fuel. With solar plants, you can't do that--the sun comes out when it wants to, and there's nothing you can do about it. So you have to somehow store the power from the sun, which is pretty difficult work, and ends up falling prey to the 2nd law of thermodynamics--you lose energy storing the energy, then lose energy getting the energy back out.
Enter German engineering. This solar power plant puts out 50 mega-watts (which is ~5% of what a typical city needs). The interesting thing is how it works: by heating up a special oil, and using that to melt salt. The salt is then stored in large silos, which are thermally insulated. The key here is that the molten salt doesn't need to do anything else to become storable energy--it's storable as it is! It cuts out the middle-man. Furthermore, using special engineering tricks, they're able to pump heat into these silos, as well as run a standard set of turbines at the same time. In essence, they've found a very good solution to the second problem.
You're asking about cost? The cost per kWh is ~.50 cents, which is ten times what standard US citizens pay now. However, this is much better than most other solar plants.
So this doesn't sound like a huge deal--after all, it's only 5% of a typical city's power needs, right? Well, the silos can be scaled up easily--they're just big tanks with salt in them. And the solar collectors don't mind if you add another row. And those engineering tricks? Just pipes and pumps, and those can be scaled up easily. So, what I'm saying is that we can easily scale this up into the giga-watt range.
As a bit of a further note, this still doesn't work everywhere--just where everything's bright and hot all the time. In particular, the Mojave desert is getting a lot of attention from power companies, who've seen the pretty tremendous success that the Andasol plant had. Now, I wouldn't expect plans for these types of power plants to show up on a casual google search, because all the technology is public domain, so the companies that would want to use this approach would have to do it as quietly as possible. But! I'm definitely interested in seeing where this goes, especially as the US power grid is starting to age.
Now, all that said, what do you think? Is the price jump reasonable? Are you for alternative energy at all costs? Would nuclear power be a better... herm, alternative? Do you just want to kill and burn as much of the environment as possible?
Discuss!
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Topic: Solar Power and alternative energy (Read 4193 times)