BATTERY TO STORE WIND

Clearly a new era is dawning. The wind energy industry is growing so big so fast it can now support the testing of technologies long around and waiting to be perfected. Perhaps wind energy’s biggest “bugaboo” is its intermittency. It doesn’t take an engineer to observe that there are times when the wind doesn’t blow.

A Stanford research paper from last fall concluded it merely takes a grid-tied system of 19 wind farms over a 500 square mile region to overcome a local intermittency (see WIND ENERGY: HOW IT’S DOING NOW) but attacks on wind energy for its intermittency persist. As a result, reports are emerging of various storage concepts. Many, like the battery system described below, are ready for field-testing. Others soon will be. (See BIG WIND TO BE STORED, USED ON DEMAND IN TEXAS)

An Xcel Energy test project will use a linked system of 20 NGK Insulators 50-kilowatt sodium-sulfur batteries to store 1-megawatt of power generated by turbines at Xcel's western Minnesota wind farm near Buffalo Ridge. The stored power can then be called on during periods of peak demand or when the winds fade.

Battery storage is one method for wind to smooth out its intermittency. (click to enlarge)

This battery test is the kind of innovation most likely to emerge when a state pushes its power producers. Ex: Minnesota last year passed a Renewable Electricity Standard (RES) requiring 30% of utilities’ electricity to come from New Energy by 2020. This year Xcel Energy, the state's most ambitious utility, expanded wind energy production and acquisition, began pushing harder for new transmission and initiated these storage tests. (And it's only March.)

Xcel Energy to store wind power with new battery
Nicola Groom (w/ Andre Grenon), February 28, 2008 (Reuters)
and
Xcel will test storing wind power in batteries
Doug Hamlin, February 28, 2008 (Minneapolis/St. Paul Business Journal)

WHO
Xcel Energy (Frank Novacheck, Director of Corporate Planning) ; American Electric Power Co Inc (AEP); NGK Insulators Ltd

NGK Insulators' sodium-sulfur 50 kilowatt battery. (click to enlarge)

WHAT
Xcel will test a 1-megawatt battery system for its efficacy in storing wind energy-generated electricity.

WHEN
- The 1-megawatt system is described as capable of storing power for 500 homes for 7 hours.
- The testing process will begin in October 2008.

It is one thing when NewEnergyNews insists the Renewable Electricity Standard (RES) offers opportunity. It is another when a major utility says it. (click to enlarge)

WHERE
- NGK Insulators, based in Japan, is making the battery system for Xcel.
- The pilot project will be at an 11-megawatt wind farm in Luverne, Minnesota, near Buffalo Ridge, Minnesota’s highest-potential wind energy region, east of Sioux Falls, South Dakota.
- Xcel is based in Minneapolis and distributes electricity and natural gas across 10 Midwestern and Western states.

WHY
- An Xcel exec described the battery system as a sort of “shock absorber” to smooth out variations in wind farm production.
- AEP is also using battery systems to increase wind’s reliability, but not on this scale.
- Financing will be from a Minnesota Renewable Development Fund grant of $1 million. (The grant must be approved by the Minnesota Public Utilities Commission.)
- Xcel currently has 15, 000 megawatts of electricity generating capacity.
- Minnesota is the U.S.’ 3rd biggest wind power producer, after Texas and California.

Xcel Energy is serious about wind. (click to enlarge)

QUOTES
Novacheck, Xcel: "We are going to use it to shape the output of the wind farm…The variability of the wind causes other supply resources on the system to have to vary to accommodate that wind…Because of the amount of wind we are going to be putting in our systems, those higher penetrations of wind can cause some problems in cycling of our systems, so we are looking at storage to provide that shock absorption to help us manage taking as much wind as we possibly can."