Concerns about power project

Dear Editor:

Beware, all that glitters… In the stampede to embrace the proposed 1,000,000 KW Riverbank Power Plant along the tranquil banks of the Back River, don’t be fooled by unrealistic promises and glitzy promotions.

In the real world, pump storage power plants have typically been constructed in geographically vertical areas like Colorado where the naturally occurring terrain affords the elevation differential required to make pump storage projects practical. Additionally, sites are selected to take advantage of the existing topography to develop the reservoir capacity to capture and reuse the water supply. To be economically feasible, the construction cost needs to come in around $1,300 per KW of installed generating capacity and have a run duration of 7–15 hours.

One will note that the naturally occurring elevation differential required for pump storage is lacking along the Back River. Indeed, a three-mile long tunnel, 30 feet wide will be required to be constructed through bedrock granite just to reach the water storage level. Then a reservoir large enough to house 1.23 billion gallons of water, a power plant, control room, and four vertical water shafts, sufficiently sized pressure relief air shafts, and cabling shafts need to be excavated through the same solid rock. Construction time is estimated to be about five years.

Now this is where some folks start thinking about job creation and the economic benefits touted by the project promoters. Dollar signs start to cloud their thinking. Promises of negligible environmental impact, 100% pollution free power, exportation of power to other areas, very low electric rates gets their hearts racing. Something for nothing, too good to resist!

The basic premise of pump storage projects is that the project will pay for itself by generating power during the peak when power is expensive and buying it back at night, when demand is low and power is cheep.

Certainly there is some truth in that premise; however, the rate differential varies daily and seasonally. On all but the most extreme days that rate differential may not be all that great.

A thorough long-term study of the demand load profile incorporating known and probable developments would be required to determine the project’s financial feasibility. This study would have to take into account that the public projections of cost ($2 billion) and the generation capacity (1,000,000 KW) bring this project in at a very costly $2,000 per KW with the availability of only 6 hours or less at full capacity.

The claim that pump storage power is virtually 100% pollution free ignores the fact that it must be recharged daily. The power to pump the water up from reservoir back to the river is probably 10 – 15% greater than the power generated when water flows through the generators. This recharge power is likely generated by conventional fossil fuel resources and imported from out of state. Clearly solar power won’t be available at night and wind resources are typically diminished at night. The project consumes more power than it produces and more energy is imported than exported.

The developer claims the project will make use of 1.23 billion gallons of water falling 2,000 feet to be held in huge reservoir tunnels. They state each tunnel will be 100 feet tall and 1,000 feet long (no measurement is described for the width, but by comparison of their graphic depictions, I estimate the width to be 75 feet). They show a total of six such tunnels for a total of 45,000,000 cubic feet of storage capacity.

Not that I’d suggest anyone might misrepresent the magnitude of construction; however, to store 1.23 billion gallons of water requires 164,500,000 cubic feet of storage capacity: nearly 22 such tunnels not the six shown in their informational information. (1 gal = .1337 cu ft). Maybe they made a miscalculation. To store 164,500,000 cu ft of water in 6 – 100’ x 75’ tunnels, each tunnel would have to be 3,655’ long.

Five or more years of loading barges at the Mason Station will likely deafen many citizens of Wiscasset and cover the town daily with a fine layer of dust and granite residue. The hauling of barge after barge down the Sheepscot will likely decimate lobstering in the river forever.

In Colorado and other western states, pump storage projects are typically incorporated with other societal benefits such as enhanced recreational use on the reservoirs, agriculture irrigation storage, and municipal water supply. None of these benefits are available with the Riverbank Power project.

If these types of projects were practical, I think we would have seen 500’ tall water reservoir towers being constructed all over the country. Like windmills, one tower couldn’t do much, but aggregated in water-tower farms, they would be easier to construct and a lot cheaper than quarrying 164,500,000 cubic ft of granite.

Finally, what are the exit contingencies for project failure either during or after construction? Are bonds being required for the estimated cost of clean-up and remediation?

All that glitters, ain’t gold.

Ron Carey

Edgecomb

General Manager Retired, Poudre Valley Rural Electric Association, Inc., Fort Collins, Col.