BPA tests the water heater's role in the smart grid

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The Bonneville Power Administration is working with a utility district in Washington to test a smart-grid concept that would use residential water heaters to help manage the fluctuations of wind energy generation.

The project will address two problems experienced on the grid: shortage of power during peak times and surges of power during windy periods.

Mason County Public Utility District Number 3 will install special devices on water heaters that will communicate with the electrical grid and tell the appliances to turn on or off, based on grid conditions and the amount of renewable energy that’s available.

While homeowners will be able to override the control device at any time, it's unlikely that they would even notice a change in temperature.

The water heaters in effect become energy storage devices — turning on to absorb excess power and shutting down when demand ramps up —leveling out the peaks and valleys of energy use.

Installation of the devices in the 100 participating homes should begin in October 2010.

A study presented to the Northwest Power and Conservation Council in 2009, estimated that 4.3 million water heaters can store 2,600 megawatt-hours by allowing the storage temperature to vary by five degrees.

According to BPA, by employing enough water heaters as storage units, the region can reduce the need to rely on the hydro system to maintain the power system balance of supply and demand, giving the power system more flexibility.

"Homeowners who choose to participate in this pilot project can help the region ease strain on the region’s electrical system," said Lee Hall, Bonneville Power’s smart grid program manager, in a press release. "They will also help the region make the best use of wind; a clean and renewable, yet variable power source."