Posted: Apr 01, 2013 12:41 pm
The_Metatron wrote:This is describing an engineering problem, not an economic problem.
I'm not sure what kind of meaningful distinction you're making there.
It has to do with balancing production with demand on the power grid. This balancing problem appears everywhere stochastic sources of power are used such as wind and solar power. Nuclear and coal plants don't have a volume control. That is, their power output is not particularly modulatable.
This means, they can't easily adjust to match demand on a grid that contains a bunch of uncontrolled stochastic generators, such has home solar and wind stations.
There are solutions, and the steampunk train idea is not far off. It just doesn't have a lot of capacity. What does the trick is pumped hydroelectric plants. It turns out there are more of these than I realized, a couple of them right here in Belgium.
When demand is low, use the excess nuclear power to fill up a big dam reservoir. When power demand is high, drain that reservoir back through the same equipment that pumped it up, using the power so produced to balance the grid.
Denmark does something similar with their wind turbines' power. They send excess over a DC link to Norway, which then simply dials down the demand on their own hydroelectric plants. When Denmark needs some power back, Norway simply opens up the valves a little farther on their hydroelectric plants. Hydroelectric is very modulatable, from nearly full shutdown to maximum capacity, and it can be done quickly.
Another approach is smart grid technology, which allows control of the stochastic solar and wind generators. While such a situation can't command power from a solar plant in the shade, it can shut down output from solar stations when it is causing a power imbalance on the grid.
I think the pumped hydroelectric is a better solution, but it's a hell of an infrastructure component to build.
That's all extremely interesting to me, thank you for the links. I'm under-informed when it comes to energy economics, but it's more intriguing the more I learn.
EDIT: And thanks NineBerry for the links, too. I wonder about the costs that go into these things. It's not enough to just say that there is a solution out there, if the solution is impractical or too expensive or whatever.