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Monday, April 12, 2010

Why wind power is not the (only) answer

I don't even remember who brought it up last time, but periodically someone finds out what I do and the discussion seems to eventually go towards the trendy topic of green power, and wind power in particular.

They almost always seem surprised at my less-than-enthusiastic response. Wind power is not the answer to life's problems and the solution to the greenhouse gas apocalypse.

Don't get me wrong. Just because I work for The Man on the power side, I am not at all interested in ruining the environment by running more coal steamers just because coal is cheap. The reality is, though, that wind power is still indirectly harmful to the environment in the half-assed way that our government is implementing it.

You've got state and federal lawmakers wanting to please the ignorant constituency, themselves fueled by Saturday-morning cartoon feel-good PSAs about saving the environment and the world, symbolized more and more as late by the ubiquitous wind power turbine that will save us all. Mandate more wind, force the big bad power companies to install more green sources, because if they won't save the environment, by golly we in Congress will force them to.

Hold on there, Spike.

If necessary, review Tutorial 2 - AC Supply and Demand, Tutorial 3 - Generation Supply, Control and Scheduling, and maybe even Tutorial 4: Basic ACE, and Reserve Sharing.

Sorry for the big assignment review, but this won't make sense unless you understand what is going on behind this topic.

The short version is this: The AC system is instantaneously supplying demand with supply. There is no practical storage capability with current technologies.

Power plants run up and down all day to match the demand curve as people wake up, turn things on, go through their lives, end the day, turn things off, etc.

It's pretty hard for some systems to regulate. And wind power is largely uncontrollable, and on the supply side the forecasting of wind resources is still hazy and new.

So what happens when you've got a lot of wind blowing, sending you hundreds of megawatts.... then morning comes, people start turning on furnaces, ovens, coffee pots. Demand takes off fast. Then.... the wind stops blowing.

Your regulating power plants who are tasked with matching demand suddenly have to keep up with the load pickup AND replace the dying wind output.

Then the wind picks up, and they have to back out of the way. In a severe case, the wind picks up too far, and the wind farms cut out on overspeed. Now the regulation power plants have to recover the loss, and about the time they get there, the wind dies off, allowing the turbine farms to re-sync at near the maximum output. Suddenly there's way too much power, and you're backing the other plants out of the way. Again.

This is an extreme scenario, but not at all unrealistic. Less severe but still significant plotlines of this type play out every single day, all over.

If your regulating plants are hydroelectric, you can probably manage OK as long as you have the water to do it and are staying within FERC/DOE/DNR/Tribal/etc. flow requirements. If your regulation is coal plants, all that running up and down is beating the crap out of them, repeatedly causing thermal flexing and wearing them out decades ahead of their life span. Not to mention, coal steamers running at anything more or less than their highest-efficiency base loading (generally about 85-90% of capacity) are relatively speaking producing more pollution in proportion to their energy output than a base-loaded plant at maximum efficiency.

Yeah. When your wind turbines are running up and down, you are killing your steamers (costing more money in the long run) and creating more pollution with them than they would if wind wasn't messing with the supply/demand equation.

There is so much more to this story, but this post is already too long. I'll come back to this later. In fact, this will be a new running subject, under the tag "energy future." We'll talk current resources, green power, smart grid, nuclear, and whatever comes up that seems relevant.

If you have questions or want me to elaborate on anything, just pounce on that comment button.

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