Slashdot Mirror
Old Electric-Car Batteries Put Into Service For Home Energy Storage
Hugh Pickens writes "Josie Garthwaite writes that old electric car batteries degraded below acceptable performance levels for autos still have enough life to serve the grid for at least ten years with a prototype announced by GM and ABB lashing five Chevy Volt battery packs together in an array with a capacity of 10 kilowatt-hours — enough to provide electricity for three to five average houses for two hours. 'In a car, you want immediate power, and you want a lot of it,' says Alexandra Goodson. 'We're discharging for two hours instead of immediately accelerating. It's not nearly as demanding on the system.'" (Read on, below.)
Pickens continues: "Deployed on the grid, community energy storage devices could help utilities integrate highly variable renewables like solar and wind into the power supply, while absorbing spikes in demand from electric-car charging. 'Wind, it's a nightmare for grid operators to manage,' says Britta Gross, director of global energy systems and infrastructure commercialization for GM. 'It's up, down, it doesn't blow for three days. It's very labor-intensive to manage.' The batteries would allow for storage of power during inexpensive periods for use during expensive peak demand, or help make up for gaps in solar, wind or other renewable power generation. One final advantage of re-using electric car batteries is that the battery — the most expensive part of an electric car — remains an asset beyond its useful life in the vehicle. 'If there is a market in stationary power for spent batteries, consumers could recognize this as an increased resale value at end of life, however small,' says Kevin See."
Your house uses more than 10kw? I really have to ask, what the heck are you doing??
I have a modest 4x2 house, with a stay-at-home wife and 2 kids. Big screen TV, and all the other creature comforts and I wouldn't even come close to use 10Kw.
In this instance I have to say 'you're doing it wrong'.
Anyone who needs emergency power isn't going to be using the inductive cooktop, air conditioner and three oil column heaters. This keeps the fridge, tv, radio, and microwave going.
In addition, if you are wanting to go solar or off-grid, then power supply is only half of the equation. The other half being how to reduce consumption. For example getting a LED based TV instead of a plasma based one or putting stuff into standby (or off) when not bring used.
As for 10KW per hour, that is huge. What is consuming that much? An industrial level hair dryer?
Jumpstart the tartan drive.
This is for grid-level storage, not in-your-home backup. Space and weight are a distant concern compared to cost.
There is an important concept called demand (or load) leveling. How much electricity the grid demands changes significantly over the course of the day, so you much design your power plants and infrastructure to handle the peak load. However the peak load is only experienced a small fraction of the time, meaning you are considerably overbuilt for maybe 16 to 18 hours of the day - especially late at night when most people sleep. The problem is so severe that many utility providers offer Time-Of-Use rates where electricity during off-peak hours is considerably cheaper (and on-peak considerably more expensive) to encourage people and businesses to use less during the day and more at night.
Batteries connect to the grid though a charge controlling inverter - a single piece of equipment. During the off-peak hours they absorb excess energy by charging, meaning the generation equipment runs more efficiently and more economically. During peak hours they release the energy decreasing the demand on the system so it doesn't have to be so overbuilt and therefore less expensive to maintain and operate.
The process of shifting load from peak to off-peak is sometimes referred to "filling the bathtub" and utility providers love it since it makes their lives much easier. Battery storage is a great way to achieve this at the grid level and anyone who manages to develop a cost effective solution stands to make a LOT of money selling and installing such systems.
=Smidge=
Geez. My house never hits 10 kW peak. Period. I suppose if my wife were baking something, we had the dryer on AND I was running the welder we might hit that.
I use a 2.5 kW generator for the house - works great except the electric stove and the dryer. If we are on generator because of a power outage, we can avoid baking, use the propane grill and just air dry clothes. That leaves the computers, lights and miscellaneous bits of civilization to work just spiffily.
I can't even imagine what he uses 10 kW for....
Faster! Faster! Faster would be better!
Yo' space ....
I monitor my power consumption using a Current Cost system (don't necessarily suggest this device, it's a bit wonky, but it works). I get 6 kW running the oven AND the dryer. The hot water heater fires a few minutes every hour during the day. I cannot see a sustained 10 kW load. Ever.
YMMV but if you're really pulling down that many amps, either you have a bunch of very, very clean people in your household.
Or you're doing it wrong.
Faster! Faster! Faster would be better!
That's an interesting solution. A Leaf's battery (24kWh at 400V) will actually power a whole house for a couple of days, but that would require getting direct access to the main battery output to sustain whole-house amperages. What he did was to connect his fridge to a small inverter, which he connected in turn to the Leaf's 12V battery. The 12V battery in a Leaf is pretty much an ordinary car battery (a little smaller than most), whose normal use is to power the interior amenities of the car. Like any other 12V car battery, it would be depleted before too long... but the Leaf automatically recharges the 12V battery from the main battery as needed.
Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.