Slashdot Mirror
Store Your Own Juice
sfeinstein writes "Power companies using dynamic pricing models to charge more for electricity during hours of peak usage is nothing new. Now, however, one company has decided to take advantage of this by using technology to buy (and store) capacity when rates are low and use that capacity when rates are at their highest." From the article: "The device, called GridPoint Protect, is the size of a small file cabinet and connects to the circuitbreaker panel. (The company also offers a lower-capacity version designed for homes, which costs $10,000.) A built-in computer powered by a Pentium chip will make intelligent purchase decisions, buying when prices are low, then storing the electricity for later use. That will make it possible to run your company during the workday with cheaper electricity that you purchased at 3 A.M."
How does it know when prices are "low"? Does it have a hardcoded database that will be inaccurate in a few months, or does it observe-and-compare prices?
Doesn't this assume that the device can store power with 100% efficiency? Seems like a 15% cost savings would be lost upfront unless the charging efficiency is at least 85%. And this doesn't even take into account the capital investment in the device itself.
Why even bother offering a home product at $10k?
i e
Besides, people should be thinking about generating their own power and pumping the surplus back into the grid, running their meters backwards (a legally protected action in most states) at a cost to the power company.
These are called intertie systems, and power companies are federally mandated to allow them:
http://www.google.com/search?hl=en&q=solar+intert
Wow! This must be a PERSONAL letter, just for me!
Instead of playing games with the power company, you can buy small-scale wind turbines for roughly $1/W. That also pays off after about three years, except unlike a battery bank, it actually reduces the real load on the electric grid, and will keep working for 20-30 years rather than 5-10.
Oh, sorry, lost my head for a minute, forgot I live in the USA. Can I "upgrade" my >45MPG TDI (diesel) Beetle to a <10MPG Explorer? Uhhh... Go Yankees!
This is nothing big -- the Swiss have been doing it for years. They simply buy power off the French grid at night from the nuclear plants, and then use it to pipe water up a mountain. Once the peak hits, they let it down to power hydroelectric plants, selling energy back to the French -- for profit.
;)
Clever bastards those swiss
DYWYPI?
It's possible to bring up a gas turbine in seconds if you're prepared for it; you leave the turbine spinning but with no actual load.
There's also a special type of hydroelectric plant called a pumped storage power station. What you do is to connect two lakes at different levels via a set of turbines. When you have excess power on the grid, you pump water uphill; when you need power, you let it run downhill. They don't have a great deal of capacity, but you can bring them online from cold in only a slightly longer time than a hot gas turbine. The one I've visited, the Ben Cruachan power station, can generate 440MW for 22 hours and can come online in two minutes.
A while back I remembered seeing proposals for storing excess electricity during off-peak hours in huge supercooled superconducting storage rings, but I haven't heard any more about it in years, and don't even know how such a scheme would work.
The problem with superconducting storage rings is that if anything goes wrong all the energy gets liberated as heat... very, very suddenly. If you had a storage ring the size of the pumped storage station described above, you'd end up dissapating 6x10^11 joules of energy... about the equivalent of 150 kilotonnes. Yum!