Wind Drives Growing Use of Batteries

[jpak]

http://www.nytimes.com/2010/07/28/business/energy-environment/28storage.html?_r=1&src=me

The rapid growth of wind farms, whose output is hard to schedule reliably or even predict, has the nation’s electricity providers scrambling to develop energy storage to ensure stability and improve profits.

A battery system in Presidio, Tex., is intended to improve reliability in the town, served by only one major transmission line.
As the wind installations multiply, companies have found themselves dumping energy late at night, adjusting the blades so they do not catch the wind, because there is no demand for the power. And grid operators, accustomed to meeting demand by adjusting supplies, are now struggling to maintain stability as supplies fluctuate.

On the cutting edge of a potential solution is Hawaii, where state officials want 70 percent of energy needs to be met by renewable sources like the wind, sun or biomass by 2030. A major problem is that it is impossible for generators on the islands to export surpluses to neighboring companies or to import power when the wind towers are becalmed.

On Maui, for example, wind generating capacity over all will soon be equal to one-fourth of the island’s peak demand. But peak wind and peak demand times do not coincide, raising questions about how Hawaii can reach its 70 percent goal. For now, the best option seems to be storage batteries.

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[zipplewrath]

1. Been known for a long time

Wind, solar, truth is even nuclear has a "throttle" problem. The load demands of the grid vary wildly from moment to moment. The power company needs to be able to "throttle" their production to adjust. They use all manner of methods, depending upon the size and speed, but it is why we all have "surge" protectors, and why we occasionally have "brown outs". They can't always keep up.

Coal, gas, and oil can be throttle very quickly. Hydro-electric is apparently only slightly slower, but nuclear, solar, and wind are very slow, bordering on useless in the short term sense. And the need to be able to handle the highest loads, means there are very frequent times when there is huge excess capacity and idle production. I've heard it proposed that ultimately, even when the vast majority of power comes from renewable sources, they will still probably have to have some coal/gas/oil plants on a grid to be able to handle large swings in demand.

"Battery" is a fairly vauge term, and I was happy to see all the technologies mentioned here, from flywheels to compressed air. Fuel cells should also be mentioned in this context. And the happy outcome is that ultimately it may lead to better energy storage devices for automobiles.

[TheWraith]

5. Some storage is necessary, but there's also other things that we can do.

For instance, electric vehicles will mostly be charged at night when demand is low and surplus is high. It's been estimated that our electrical grid produces enough surplus power right now to drive 80 million electric cars.

[zipplewrath]

6. Those batteries could be used too

There have been proposals to let a smart grid "use" those batteries in the cars to store electricity to manage the short term variations in the power grid (measured in minutes and seconds not hours). There have also been suggestions to have batteries as part of the standard home build. They act as a great surge protector, as well as moderating those irritating short term power losses. A true smart grid that extends into the home could even send a signal to suggest that certain appliances power down thru the surge.

[FBaggins]

7. Nuclear's problem is in the other direction however

and is rarely an issue.

With nuclear, the problem is that it's a great big generator that (with some exceptions) is either "on" or "off" - so you can't "throttle" (as you said) back very easily. However, that's not much of an issue in most cases since you don't save any money by cutting it back in the first place. There's almost always some other form of generation that you're going to turn off before you cut the reactor out of the mix.

And, of course, nuclear doesn't benefit from batteries since "can't turn it off" and "can't turn it on" are very different problems.

[zipplewrath]

8. Yes it is

I've usually heard that nuclear is used almost exclusively as "base power". The reasons vary, some suggesting that because they are so expensive, they want them to produce the most. But the more common explanation is once it's running, you're not going to vary the heat output much. You can literally "blow off steam" if you have to, but they are loath to vary the output much. I suppose if pressed, they might work on that technology, but currently that isn't used very much. I'm curious to know what they do on nuclear powered ships. I'd suspect they just dump heat overboard.

[MineralMan]

2. Interesting. Back in the old days before 1936, farmers used windmills and

batteries to electrify farms that were not on the grid. Windmills charged a bank of storage batteries, so power could be used continuously and stored when there was no wind.

A wind generator produced 40 volts DC, which was used to charge a 32 volt bank of batteries. Everything from lighting to radios was produced to be operated by that 32 volt DC power. I have an old 32 volt light bulb from that period.

In 1936, rural electrification was introduced and, slowly, grid power was delivered to the farm communities. But, the old 32 volt DC systems survived for a long time. Old Sears catalogs from the 20s and 30s had all the equipment needed for these 32 volt systems.

Everything old is new again, it seems.

http://en.wikipedia.org/wiki/Rural_electrification

[jwirr]

3. Thank you for the link. I am old enough to remember those good old

days. I knew it could be done with those simple windmills just not how.

[MineralMan]

4. Well, I can't remember anything before about 1950, when I was

five years old, but I did visit a farm that was still using 32-volt wind and battery power on the farm. I was 10 years old in 1955, and was very, very interested in that. My uncle explained it all to me, and showed me how he had to add water to the batteries and so forth. He actually was connected to the grid by that time, but still used the old wind-power system to power the barn and workshop area with lights. He had an old 32-volt radio in the barn, too.

He died a few years later, and I bagged one of the light bulbs after the funeral. I still have it.

The thing about those systems is that it wasn't up to today's energy usage. A few light bulbs, a radio, and maybe a washing machine motor. That was about the extent of what it would power. We wouldn't be happy with its capabilities. For those old farmers, though, it was miraculous.

Today, a similar system is certainly possible for individual dwellings. In fact, you can buy all the components and install them yourself. It's being done again and people are unhooking from the grid. They still have to simplify their use of electricity, but that's all part of the good.