Company looks for ways to store wind power

By ERNEST SCHEYDER

NEW YORK — One problem perhaps more than any other has proven a drag on the long-term prospects for wind power: how do you turn on the lights when the wind isn’t blowing?

A New Jersey company said it has joined with Michael Nakhamkin, one of the top thinkers in energy storage, to develop new ways to trap wind-generated power in underground reservoirs.

Nakhamkin has helped develop technology that pulls excess energy off the power grid — usually at night — to run compressors that pump air into sealed, underground caverns that previously held oil, salt or natural gas.

When the grid needs power, air is released and heated to run air expansion turbines. The heating process uses about 100 megawatts of power from natural gas and 200 megawatts of power from the compressed air.

The announcement comes just as a drilling boom for natural gas heats up nationwide. Natural gas that can be reached with new technology has supporters in both the private sector and in Washington because it releases fewer of the greenhouse gases that can lead to global warming and because it has been found domestically in massive quantities.

In urban areas where underground storage isn’t feasible, or where bedrock makes drilling a hole expensive, ground-level pipes can be used to store the air, though the capacity is diminished.

The technology has been used at an Alabama plant since the early 1990s, but the latest version allows utilities to quickly generate power — at different levels — when needed, and to arbitrate between peak and off-peak hours.