Friday, October 3, 2008

The Element That Could Change The World

Schematic depicts the inner workings of a vanadium battery, now in use in a Utah plant, that can supply 250 kilowatts for eight hours. VRB Power Systems

From Discover Magazine:

Making green energy work may depend on three unlikely heroes: an Australian engineer, a battery, and the element vanadium.

February 27, 2008, was a bad day for renewable energy. A cold front moved through West Texas, and the winds died in the evening just as electricity demand was peaking. Generation from wind power in the region rapidly plummeted from 1.7 gigawatts to only 300 megawatts (1 megawatt is enough to power about 250 average-size houses). The sudden loss of electricity supply forced grid operators to cut power to some offices and factories for several hours to prevent statewide blackouts.

By the next day everything was back to normal, but the Texas event highlights a huge, rarely discussed challenge to the adoption of wind and solar power on a large scale. Unlike fossil fuel plants, wind turbines and photovoltaic cells cannot be switched on and off at will: The wind blows when it blows and the sun shines when it shines, regardless of demand. Even though Texas relies on wind for just over 3 percent of its electricity, that is enough to inject uncertainty into the state’s power supplies. The problem is sure to grow more acute as states and utilities press for the expanded use of zero-carbon energy. Wind is the fastest-growing power source in the United States, solar is small but also building rapidly, and California is gearing up to source 20 percent of its power from renewables by 2017.

Read more ....

No comments: