Even though wind energy is a clean and cost-effective source of energy, it does have one slight drawback: no one can control when the wind blows. This occasionally leads to difficulties in matching consumers’ demand for energy with the available supply. For instance, when the wind is strong but demand for electricity is low (i.e., late at night), wind farm operators may have to turn turbines away from the wind to avoid overwhelming the electrical grid. Of course, the opposite scenario can also occur, in which the wind is not strong enough to meet demand for electricity during a peak period.

One potential solution for this problem has been the subject of much attention and research lately, and that solution is the use of batteries. Really, really, big batteries, that is. Batteries could help by allowing wind farms to store energy during periods of low demand and then transfer it to the grid when demand is high. These batteries would also come equipped with computers that could ensure the electricity is released at a fixed rate, making wind power similar to natural gas and other power sources which can start or stop production at a moment’s notice. Such a system would allow utility operators to schedule the supply of wind energy precisely according to need, increasing dependability.

Now, when I think of batteries, I inevitably imagine a sleek-looking pair of AA’s. However, it turns out batteries can come in all sorts of shapes and sizes if you look in the right places. A team at the University of Minnesota recently completed a study in partnership with Xcel Energy to determine whether a battery system could, in fact, be effective at transferring energy from off-peak to on-peak availability. Sure enough, the experiment was a success, but the battery they used (manufactured by NaS) was the size of two 18-wheelers and weighed a whopping 80 tons! And this is just one kind of exotic battery that may eventually be used in conjunction with wind farms; another is a flywheel system in which energy is transferred to a free-spinning rotor on an axis and stored kinetically. Pretty cool, if you ask me.

As you might expect for such bulky batteries (even the flywheels are the size of water heaters, and you need lots of them), the main drawback is that they’re not yet cost-effective. But as the American Wind Energy Association’s (AWEA) Into the Wind blog reminds us, that’s okay, because grid operators can account for the variability of wind by utilizing other sources of flexibility in the grid:

“Every day, grid operators constantly accommodate variability in electricity demand and supply by increasing and decreasing the output of flexible generators – power plants like hydroelectric dams or natural gas plants that can rapidly change their level of generation.”

In fact, AWEA estimates that the US could increase its wind capacity tenfold before battery storage would really be necessary.

In the meantime though, battery storage is a neat trick that would have its uses. For instance, many small towns in isolated areas are not well-served by transmission lines. If the transmission were to fail for some reason, batteries could allow the town to keep an emergency center open until power was restored. It’s safe to say the Energizer Bunny would be proud.

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