Bob Pierce answers questions about energy efficiency, consumer products, and cooperative governance. He is Clearwater Power’s Chief Operating Officer and welcomes your questions on our Ask Bob page.
Can we replace the power we receive from the 4 lower Snake River dams with solar power?
Some might think if we simply install enough solar panels capable of generating the same amount of kilowatt hours as the 4 lower Snake River dams, then we could breach the dams without consequence to our power supply. However, operating a reliable power grid isn’t quite that simple.
The 4 lower Snake River dams provide reliable hydropower to Clearwater Power and other cooperatives. Hydropower is called a firm resource because it is readily available 24 hours a day, 7 days a week, and can be adjusted instantly to meet demand. Operators keep the turbines in a spinning reserve (spinning but not connected to the grid), so they can instantly be switched into the grid’s supply when needed. For example, if the wind speed at a wind turbine drops suddenly, operators use hydropower to jump in and keep our lights on. This is something that can happen in the middle of the night when solar panels are not generating power.
Batteries are available to store solar power for use during the night, but they have some drawbacks. They are expensive and would be needed in large quantities. Additionally, for solar power to replace hydropower, we would need to store more than 1 night’s worth of energy for longer periods than currently capable.
In our region, energy generated in the summertime would need to be stored for use in the wintertime.
Clearwater Power has a peak demand nearly 3 times higher during the Northwest’s winter cold snaps than during the summer months. Unfortunately, solar power has a generation profile opposite our local needs. It generates the most in the summer when our electric load is the lowest. Then, in the winter when heat is turned on in homes and businesses and the electric loads skyrocket, solar only produces about 20% to 25% of what it produces in the summer.
With the battery technology available today, it is simply not feasible to store energy long enough and in large enough quantities to replace hydropower, which currently supplies 85% of our power.