Xcel Energy announced the preliminary results of the company's wind-to-battery test project being conducted in Minnesota, USA. According to these results the technology works. Xcel Energy started this project in 2008, using a 1 MW battery storage device to demonstrate the technology's ability to store excess wind energy, and pass that energy onto the power grid when necessary. This is the first of its kind technology used in the United States.

Early results show the following capabilities of the storage technology:

• effective wind energy shifting from off-peak to peak availability
• reduction in compensation for variable and limited predictability of wind power generation
• power grid stability achieved through provision of voltage support
• responding to real-time imbalances in the power grid between generation and load

The storage facility, however, is not very small – weighing at about 80 tons, and using 20 50 kW battery modules, it can store about 7.2 MWh of energy, and power about 500 homes for 7 hours.

Storing power generated from wind turbines is an important precondition for transitioning towards a more wind power dependant power grid. Renewable energy harnessing technologies such as wind and solar suffer from issues with intermittency of power generation, putting quite a bit of load on the power grid, but being able to store generated power during low-consumption periods, will greatly increase their reliability.

[source: Xcel Energy]