Skagit needs utility-scale battery energy storage sites

Should Skagit County approve utility scale battery energy storage projects?

Yes. The size of the project, the type of battery and where, exactly, those projects should be located are subjects that will require public discussion. However, as their costs have fallen more than 99% over the last 20 years, large batteries have become very helpful in keeping electricity rates down. Here’s why:

The American electric generation system is significantly overbuilt. There’s more capacity to generate electricity than we can use, most of the time.

For instance, electric demand in northwest Washington is higher at 6:30 on a winter morning, when people get up and turn on water heating appliances and lights while electric heat is already running, than it is at 2 p.m. on a mild spring day.

To supply electricity during the “peak hours,” the system needs to be built to generate more than enough (to account for transmission losses and transient equipment startup surges) for the single hour during which demand is highest.

Depending on the specific location, demand during an average hour may be a third, or even a sixth, of the peak hour’s demand. During any given year, the lowest hour may only have a tenth the demand of the peak hour.

Currently, utilities rely on “peaker” generation plants to meet demand during the top 200 or so hours of an 8,760-hour year (24 hours for 365 days). Peakers are capable of operating for thousands of hours a year, but actually run for tens of hours a year. To pay for these underused assets, their operators have to charge utilities high prices – sometimes more than $10 per kilowatt-hour. A utility that has to buy energy from a peaker pays $10 for a kilowatt hour and then sells it for 13 cents. That cost eventually gets included in the average rate, and keeps rates up for everyone.

Inexpensive storage enables lower-cost generation assets that have already been built, to be used more. A battery storage system enables the utility to buy off-peak energy at normal wholesale costs of 2 or 3 cents a kilowatt-hour and store it. Sometimes, off-peak energy available in the western U.S. will include renewable energy available at near-zero cost. California is well into the process of building more solar generation capacity than it needs during some off-peak hours.

Even here in Washington, overnight wind power can be more than the grid needs. Without storage, this energy would be “curtailed.” The plants would be turned off and the otherwise-almost free energy wouldn’t be generated at all. A utility-scale battery allows this near-zero-cost, zero-emission electricity to be captured for use during peak hours.

If there’s a hot summer or a cold winter that would require more peaker use than average, a battery storage system can pay for itself, keeping rates down for everyone, within a year or two. That’s what happened with the first major utility battery system in south Australia a few years ago.

Batteries can also relieve local grid congestion, reducing the need to build new power lines and substations.

There’s been discussion about lithium batteries as fire hazards. Utility batteries will usually be lithium iron phosphate batteries, which aren’t hazardous. The lighter, higher-capacity lithium-ion (nickel, cobalt, manganese) batteries used in cars aren’t necessary for utilities, because utility batteries can be physically larger and heavier without performance consequences.

Lithium ion batteries do occasionally catch fire, but the risk is low. Some battery-powered car fires have gotten significant publicity, but the probability of a lithium battery car fire is less than 1% of the probability of a gasoline car fire. Gasoline is more flammable than batteries.