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Thursday, November 13, 2008

Xcel Energy innovates, with a grid-scale battery storage project - a first of its kind in the nation.

I will excerpt from Strib's online report, but this Google gives other sources reporting on the same matter:

Xcel looks to harness wind energy for use even when there's no wind -- The project, which also includes the state and a tech firm, is installing a battery that is the first U.S. device that can store wind power.
By DEE DePASS, Star Tribune - Update: Nov. 12, 2008 - 10:20 PM

Next spring Xcel Energy Inc., the state of Minnesota and a Virginia-based technology firm will test the first battery in the country capable of storing wind energy.

The battery consists of a score of 50-kilowatt modules. When it is fully charged, the massive sodium-sulfur battery -- which weighs about 80 tons -- can store 7.2 megawatt-hours of electricity. That's enough to power 500 homes for about seven hours. It will cost more than $5.4 million to buy and install the battery and analyze its performance.

The technology could help allay critics of wind energy, who lament that no electricity is produced when there's no wind. If successful, the battery will store wind energy and release its power onto the electrical grid when the air is still.

Xcel, which invested $3.6 million in the project, expects the battery "to become very important to both us and our customers," [Xcel Chairman and CEO Dick] Kelly said.

Xcel, the largest wind-energy producer in the country, is working to make it easier to integrate renewable energy onto the electrical grid as part of its "Smart Grid" strategy. It has a mandate to generate 30 percent of all its energy from renewable sources by 2020.

Xcel bought the battery from Japan's NGK Insulators Ltd. The batteries are used in Japan to store wind energy, and are used in a few nonwind applications in the United States.

"But this is the first U.S. application of the battery as a direct wind-energy storage device," Kelly said.

In addition to Xcel, the Minnesota Renewable Development Fund is contributing $1 million to the project. GridPoint, a power grid management firm based in Arlington, Va., kicked in $750,000. The University of Minnesota will analyze the battery system and grid connections. Other participants in the project include the National Renewable Energy Laboratory [NREL is an abundant source of much high quality alternative energy information] and the Great Plains Institute.

Xcel announced this month that it will develop 351 megawatts of new wind-energy production by December 2011 -- enough to power about 110,000 homes. The company said it plans to increase its current wind resources by more than 10 percent.


There is more detail in the Strib online item, I only excerpted. See, also, here, here, here, and here. I would not use the term "groundbreaking" as much as the term "incremental innovation." It is a logical next step, but for the prices and risk involved, the fact nobody else went out on that limb, the company and collaborators deserve praise and respect. It is a major step, both for battery storage as a high-power grid regulatory addition, and specifically as a wind farm or wind power adjunct.

Respect Xcel for taking the step, and hope it is a trouble free and quickly utilized thing, industry wide. If economically and technologically a success, it means a lot for wind power, and for solar power on a shady, rainy day.

_________UPDATE________
For tech wonks, info on the battery technology from the manufacturer's website is here.

Clearly this is not simple technology. Operation at 300 Celsius with liquid sulfur and liquid sodium requires tight sealing to keep water and water vapor out. During earlier days sodium cooled nuclear reactor core technology was explored, with the sodium remaining liquid, but via a heat exchanger system producing the steam needed to drive a power turbine, in turn driving the geneartor. If that technology was ever comercialized I do not know of it, the high reactivity of liquid sodium being a safty worry from day one. For this battery the chemical reactivity is no different, but it is not used in any reactor core situation where damage and chemical reactivity would have been coupled with radiation exposure and radiation release worries. Still, I would never want any of this battery technology placed without due consideration of tampering and terror vulnerabilities. NIMBY. Understandably NIMBY. Out in the Dakotas, very rural Minnesota. Away from people and property, from stream contamination or soil contamination worry.

The manufacturer's website indicates a primary target market for peak demand smoothing and saving that way, with the interruptible/inconsistent power generation smoothing now being seen as a secondary market with Xcel Energy stepping to the plate to test it. If Xcel has good experiences, the secondary market could surpass the primary - although in essence it is peak smoothing either way, whether it smooths load demand irregularities or generation irregularities, it smooths variability to stabilize the grid in ways other options fail to offer an economical answer. Capacitor storage and transmission line field storage exist, but not on as persistently long a time frame as high-power battery technology promises, if successful.