Monday, July 09, 2007

Sodium-Sulfur Batteries

A new type of a room-size battery, however, may be poised to store energy for the nation's vast electric grid almost as easily as a reservoir stockpiles water, transforming the way power is delivered to homes and businesses. Compared with other utility-scale batteries plagued by limited life spans or unwieldy bulk, the sodium-sulfur battery is compact, long-lasting and efficient.

Using so-called NaS batteries, utilities could defer for years, and possibly even avoid, construction of new transmission lines, substations and power plants, says analyst Stow Walker of Cambridge Energy Research Associates. They make wind power — wildly popular but frustratingly intermittent — a more reliable resource.

American Electric Power (AEP), one of the largest U.S. utilities, has been using a 1.2 megawatt NaS battery in Charleston, W.Va., the past year and plans to install one twice the size elsewhere in the state next year. Dozens of utilities are considering the battery, says Dan Mears, a consultant for NGK Insulators, the Japanese company that makes the devices.
I think batteries are going to be crucial to transition to renewable energy as solar and wind power are both intermittent. Hopefully these NaS batteries will help make it happen.

The key question of course is price. How does this battery look?
The biggest drawback is price. The battery costs about $2,500 per kilowatt, about 10% more than a new coal-fired plant. That discourages independent wind farm developers from embracing the battery on fears it will drive the wholesale electricity prices they charge utilities above competing rates, says Christine Real de Azua, spokeswoman for the American Wind Energy Association.
Ok, this paragraph makes absolutely no sense to me.

First, shouldn't batteries be priced in kWh not kW? Reporters always screw that up.

Second, why is it being compared to a coal-fired plant? The battery will be discharging its energy at peak energy times which is provided by natural gas plants, not coal which is typically baseload. And is this comparison looking at the cost of fuel, or just of making the plant?

Third, why would using batteries make wind energy more expensive? Unless currently wind power does not get discounted for the fact it is an intermittent source of energy.

What about other solutions to the energy storage problem?
Meanwhile, other storage devices are gaining traction, too. A group of Iowa municipal utilities plans to use wind turbines to compress air during off-peak hours that will be stored in an underground cavern. The air would be released at peak periods to run turbines and generate power for about 200,000 homes. Another technology, the flywheel, has a massive cylinder that can spin for days after being started by a generator. The cylinder can then activate a turbine to supply electricity for a few seconds or minutes when it's needed, for instance, to head off an interruption to a computer center from a lightning strike.
I wish they would have done a cost comparison between the NaS batteries and these other forms of storage.

But, if this technology is as promising as the article makes it out to be, it is one to keep your eyes on.

via USA Today via Instapundit


Anonymous said...

I assume that the 10% cost figure is based on current coal fired plants costs which are certain to go up as carbon capture becomes required. Other costs are likely to rise also. I wonder what a future cost comparison will be like, say in 5 to 10 years. Also, all the activity seems to be large scale and home or small business scale and solar or wind isn't being pursued. Isn't that a "vast" potential market? I would think a chicken farm could go solar/wind with this and always have the fans going and never worry about a power line or plant going down.

Fat Knowledge said...


Yeah, I too wonder what the numbers will look like in 5-10 years.

Good question about using these on the home or small business front. Article didn't mention them, but I am not sure why.

Post a Comment

Note: Only a member of this blog may post a comment.