Largest Sodium Sulfur Battery Powers a Texas Town

separsons writes "The largest sodium sulfur battery in America, nicknamed 'BOB,' can provide enough electricity to power all of Presidio, Texas. Until now, the small town relied on a single 60-year-old transmission line to connect it to the grid, so the community frequently experienced power outages. BOB, which stands for 'Big-Old Battery,' began charging earlier this week. The house-sized battery can deliver four megawatts of power for up to eight hours. Utilities are looking into similar batteries to store power from solar and wind so that renewables can come online before the country implements a smart grid system."

Comments

Game of telephone

[Rufus211]

It's amazing the game of telephone that happens when blogs steal news stories from blogs that steal news stories from blogs.

Inhabitat: "Electric Transmission Texas ponied up $25 million to build the battery, and will add $60 million to build a second transmission line by 2012."

PopSci: "Electric Transmission Texas helped put the battery project together for around $25 million. But the utility has also agreed to build a second 60-mile transmission line to Presidio for about $44 million by 2012."

NPR: "The other solution for this town would be to build a second line, and that line would cost somewhere in the range of $40 to $50 million. And so a battery project in the $25 million range looks pretty attractive."

They all agree the battery costs $25mill, 2/3 agree that the 2nd transmission line will be built in 2012, and none of them agree on the price of the 2nd line.

Re:Game of telephone

[SpzToid]

Not to detract at all from your point, however there's something worth pointing out I learned while listening to NPR.

This particular city has a contract with a Mexican power company, to provide backup power during the all-too frequent times the lone cable to the US power is broken. However 'some time' is required to switch the city from US to the Mexican power grid. The purpose of this battery is to make the switch from US to Mexican power seamless to the end-user. Therefore, 8hrs is plenty of time for the battery power to last.

Perhaps the battery buys the town time in more ways than one. Now the town is less reliant on someone building out that spare US transmission line for awhile longer. And I'm sure that price varies on which year the 2ns US power line is built.

Leaky battery

[iliketrash]

"The house-sized battery can hold four megawatts of power for up to eight hours."

"Power" is not "held." Power is delivered. Energy is held. The unit of energy is joule.

NPR Link

[VTI9600]

This story originally came from an NPR interview. Here is a link.

Re:from the article

[marvinglenn]

Do you have a reference to the fact that the battery needs to run at 350C?

You could start with Wikipedia: http://en.wikipedia.org/wiki/Sodium-sulfur_battery

It seems a bit impractical to heat a house-sized building that much, especially when you have lost power.

Good insulation, and you don't heat the building, you heat the guts of the battery. Also, the lost energy is likely heating the battery.

I'm guessing a 4MW generator would take a couple of minutes, maybe 10s of minutes, to spin up to capacity.

Not the ones I've seen. (Hospital and nuke reactor backup.)

Re:Energy not Power and Batter Life

[uglyduckling]

They can last about 2,500 complete cycles or 4,800 80% discharge cycles. (From the wikipedia article linked elsewhere). Presuming a power outage once a week requiring 80% discharge, it would last about 90 years, if the number of cycles is the only thing determining its longevity.

Re:That's a great price!

[sFurbo]

No, Sodium-sulphur batteries scale down horribly. They need to run hot enough for the sulphur to be molten*, and keeping large things hot is easier than keeping small things hot, as the thermal energy scale with the cube of the size, but the escaped heat scales with the square. I don't know how small they can get, though.

*According to wikipedia, they need to run even hotter, 300-350 degree celsius

Re:from the article

[MichaelSmith]

Reportedly many communities in Alaska are serviced by power generated by massive diesel generators.

Well of course they are. Diesel is the default conservative power source for remote communities in Australia but photovoltaics are moving in. Solar power may not work as well in Alaska but wind power may do the job instead. Combine that with a BoB and you have a good reliable power supply.