Tuesday, June 05, 2012

Transforming how we use energy - Part 2

I listened to a very educational talk by Maggie Koerth-Baker about our energy future. She wrote a book: "Before the Lights Go Out: Conquering the Energy Crisis Before it Conquers Us". It was a great talk and I took the liberty of distilling more of the salient points. This is part 2.

"Shared systems, like our transportation infrastructure and the infrastructure of how your house is built, all end up influencing how you use energy and the decisions that we make. The average American uses twice as much energy as the average European, but it's got nothing to do with Europeans being better than we are or more moral. It's because their infrastructures are set up in a way that it's easier for them to make these choices, often without having to think about it. The example I use is that I live in Minneapolis. I live right near a bus line that takes me anywhere in the city. Between that and a great bicycle infrastructure, my husband and I get away with only having one car between the two of us. But if I went down to Kansas City, they don't have a bus system like mine. They don't have that transportation oriented bicycle path system. So if I said, "You should just own one car and you should drive less," I'm telling them, "You can't access your job very easily. You can't get to the services you need and want. You can't participate in your community in the way that you want to participate." That's not fair.

The electric infrastructure is not a perfect system. It evolved, rather than was designed, pieced together from this little patchwork of individual grids that weren't connected to each other in some cases until the 1970s. We haven't had a national grid system for very long. All of these grids came together with priorities of being built quickly and being built cheaply, with the priority of being the best system it could be or to plan for the future. A system that evolved to be used with coal, natural gas, nuclear power and hydroelectric power, all of which to varying degrees can be controlled. Wind and solar are different. You can't ask that wind farm to make more electricity. The grid is not a stable system. There is no storage. We have to balance supply and demand, perfectly every minute of every day, forever, and all manually. If we have too much wind and no demand for it, we can't do anything with it.

There are ways to store energy that don't involve building giant batteries. One of those things is called pumped hydro. You build a couple of reservoirs at different elevations. At night, when electricity is really cheap because there's not much demand for it, you use electricity to pump water up from the lower one to the higher one. The next day when demand is rising, you run that water down the hill and create electricity. One of the fun things about wind is that in a lot of places where we get most of wind from in the US, wind blows more at night than it does during the day, but electricity demand is lowest at night than at any other time. Another thing is called compressed air energy storage. At night you use the wind turbines to generate electricity that powers an air compressor, which fills porous rock underground with compressed air. The next day when wind demand rises, you basically just run the system backwards and let that compressed air out, which runs a generator."

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