Wind, Water and the Problem with Too Much Energy

Bonneville Power Administration's John Williams briefed the Energy, Environment and Technology interim legislative committee last week on the challenges presented by over generation caused by high water and wind energy integration.

High water years such as this one create a need for environmental redispatch, or the release of excess energy in a way that is sensitive to environmental objectives. When system conditions trigger environmental redispatch to reduce the load, Williams said, BPA prioritizes energy production reliability, fish protection, mitigating increased costs to BPA customers, and supporting integration of renewable energy sources such as wind power.

Williams noted that, for some, the current over generation situation raises the question of the relevance of the four lower Snake River dams. Replacing these energy sources, he says, is a question of replacing the generation of power valued at half a billion dollars in load peak demand support and transmission support as we take power from other states and move it to the load centers.

If the lower Snake River dams were to be removed, Williams said, natural gas would be the most likely solution for replacing the power they generate.

BPA has created a wind integration team to find and develop creative solutions to integrating and supporting wind development in the region. Transmission plays a huge role in wind integration, and BPA is looking toward improving transmission throughout the Northwest, Williams said.

While integration of wind power has contributed to the need for environmental redispatch recently, Williams said excess generation from water conditions alone has created the same situation in the past.

High water years, in short, produce problems. Water must be moved through turbines rather than spilled over dams to reduce harm to fish. Spill produces a higher quantity of Total Dissolved Gas (TDG) in the water, which harms fish. Still, reduction of wind power for environmental redispatch is a last resort after TDG caps are reached and thermal power is reduced.

Williams stressed the need to reach some type of balance with all interested parties including other energy suppliers, users, and elected officials. The general public is becoming more aware of issues and is questioning - and sometimes criticizing - the reduction in wind power due to over generation.

Idaho does not have a renewable portfolio standard (RPS)like other states have. The renewable portfolio standards are driving wind development in the Northwest. Economics are a big part of why states went to mandatory renewable energy portfolios. There is a cost for increasing wind power. For example, in the case of redispatch, compensating wind generators for losses would increase costs to BPA customers, and be an incentive for other energy producers to seek compensation for reducing their generation.

In the past, BPA was able to sell its excess power to California, resulting in cost savings to its customers. As wind power has increased, secondary revenue sources like this have dried up. Wind developers are also purchasing transmission rights, which decreases BPA's ability to transmit power to other states.

Williams noted that wind power has far exceeded initial analyses of integration needs. Compared to hydro power, wind generation load is still one fifth to one fourth as much generation, with a lower level of consistency.