Wind and gas

Wind turbines generate electricity very irregularly, because the wind itself is inconsistent. Therefore wind turbines always need backup power from fossil fuels to keep the electricity grid in balance. Gas turbines are the best way to do this. They are able to respond quickly and push power production when wind generators stop suddenly. They can be turned on and off almost instantly, whereas traditional coal-fired plants need to be maintained in a very inefficient standby mode if they are to respond to large fluctuations in power demand.

A proliferation of windmills, then, can become a windfall for gas sellers, as the cases of Spain and Germany, Europe’s leading producers of wind power, show.

By the end of 2007 Spain had 14,700 megawatts (MW) of installed wind capacity, according to Enagás, which manages the national gas network, producing 8.7% of the country’s total power supplies. Most of these wind generators are located in scarcely populated areas, while the power consumption is concentrated in big cities with their many air-conditioned buildings. The peak load of the Spanish power grid is thus in the hot summer months—but this is precisely the time of year when there usually isn’t much wind.

For this reason, more and more gas turbines are being installed near consumers in the suburbs of Spain’s cities. Only last year, Spanish power providers added 6,400 MW of gas-turbine power capacity, taking the total installed capacity of gas turbines to 21,000 MW. Natural gas has become the main source of electricity generation in Spain, and according to Enagás, 99.8% of the gas used in Spain is imported. Most of this comes via pipeline from Algeria, but the import of liquid natural gas (LNG) by ships will increase.

Germany has more than 20,000 wind turbines with a total capacity of 21,400 MW. Wind power’s share of total electricity generation has risen in line with that of natural gas since 1990. Germany’s gas consumption for power generation more than doubled between 1990 and 2007, and now represents 11.7% of the country’s total power generation. The country imported 83% of its natural gas supplies.

Source: WSJ, 11/09/08