HOW WIND TURBINES GENERATE ELECTRICITY

Integration with Hydropower and the Power Grid

The amount of power used by communities varies throughout the day and changes from season to season. For instance, more power is used in the morning when people wake up and start taking showers and using appliances. And more power is need on cold winter days and hot summer days when heaters and air conditioners are in peak use.

The load (amount of electricity) on the power grid, however, must always be equally to the amount demanded. Through sophisticated programs, electrical generation from all sources is balanced to assure there is neither too much nor too little available to consumers.

Integrating wind power into the power grid makes this balancing act even more difficult. The reason is that wind does not always blow consistently, which makes it a highly variable resource. If it's a cold day and there's no wind, where's the additional electricity going to come from? Likewise, if there's a lot of wind but not enough demand, what electrical generating resource should be idled?

And to make this dilemma even more difficult, some generating resources (like coal fire powered plants) can not be brought quickly on and off line.

Fortunately, hydropower is an energy resource that can brought on and off line quickly. And since hydropower represents over 60% of the Northwest's generating capacity, the Northwest is uniquely well suited to integrate wind power into its mix of power resources.

In a best case scenario, for instance, when wind turbines are operational more water can be stored in the reservoirs of hydropower projects. And when the wind is blowing poorly, water from these reservoirs can be used to generate more electricity.

Even with the good fortune of having hydropower available, engineers are quickly discovering how difficult this new balancing process is. To fully bring the benefits of wind power to the Northwest, teams of people are working on the following:

1. Additional transmission lines are being built to connect wind and other remote renewable resources to metropolitan communities.
2. New technologies and computer programs are being used to better manage bringing power on and off the grid. For instance, new wind stations will provide better forecasts for how much wind to expect and when; new computer programs will help operators respond more quickly to unexpected changes in the supply and demand of electricity; and better models will be developed to determine how much reserve capacity (additional power resources to meet unexpected demand) needs to be available.
3. New agreements and protocols are being put in place to better define when wind generators will quickly slow or stop operations when too much power is being generated.
4. In addition to hydropower, finding other sources of power that can be used when wind power is not as available as needed.

Working together, the Northwest is well positioned to use wind power as a primary means of meeting the region's new demands for electricity.