18 May 2017 — 0121 mdt
Flathead Electric overstates the advantages of hydropower
In the May, 2017, issue of its newsletter, Light Reading, the Flathead Electric Cooperative presents a list entitled Advantages of hydropower. Some of the alleged advantages don’t make it past a quick fact check.
FEC Assertion: Hydropower has virtually no carbon footprint.
Fact check. Generally true.
FEC Assertion: Hydropower is reliable. Unlike solar or wind energy, it is unvarying and independent of weather and other factors. Intermittent resources like solar or wind need hydropower to fill the gaps when the sun isn’t shining and wind isn’t blowing.
Fact check. Only partly true. A hydroelectric dam such as Hungry Horse Dam with a large storage reservoir can be operated to provide a steady supply of electricity that can be adjusted to meet demands. But a run of the river dam varies its output as the river running through its turbines varies its discharge. In the Pacific Northwest, rivers peak during the spring runoff season, often by an order of magnitude. Hydro is not unvarying.Recommended reading: Are solar and wind really killing coal, nuclear and grid reliability?
FEC Assertion: The hydropower projects in our rivers provide effective flood control for Northwest communities, and have created recreational opportunities as well.
Fact check. True, but not the whole story. Dams disrupted and diminished salmon fisheries, and eliminate whitewater recreation when rapids are flooded by reservoirs.
FEC Assertion: Water from rivers is a purely domestic resource that cannot be interrupted by foreign suppliers, production strikes or transportation issues.
Fact check. False. The Columbia River system originates in British Columbia. So do the Kootenai River and the North Fork of the Flathead River. Canada is our neighbor, but it’s also a sovereign nation and thus a foreign supplier.
FEC Assertion: Even though the law states that existing hydro is not renewable, it is largely viewed as a renewable form of energy that does not rely upon finite resources like natural gas or coal to generate power.
Fact check. Viewed by whom? Water is a renewable resource, but a hydroelectric dam has a limited physical and economic life. Reservoirs fill with silt. Initially, that reduces the reservoir capacity to store water, and reduces the amount of electricity generated. Eventually, silt makes the dam uneconomic.
FEC Assertion: Hydropower turbines are capable of converting 90 percent of available energy into electricity, which is more efficient than any other form of generation.
Fact check. True. But FEC needs to watch its terminology. Turbines drive generators. If a turbine is 90 percent efficient, and the generator it drives is 95 percent efficient, the net efficiency is 86 percent. There are also energy losses during the water's journey through the penstocks to the turbines.