Hydropower Plant Revenues Climbing

Electricity produced (kilowatt hours):
2007
May: 2,944,976
June: 142,282
July: 149,522
August: 6,003
2008
May: 1,686,405
June: 1,076,625
July: 1,840,241
August: 858,000 *
*Based on kwh produced up to Aug. 11.


With drought-like conditions choking Black River flows last summer, Watertown officials were looking skyward for a climatic abracadabra to produce rainfall that would boost hydropower revenues. This summer has been quite the opposite. With more than ample rain, the city has operated its hydropower plant daily, something it couldn't do last summer.
City officials actually shut down the Marble Street facility during portions of June, July, August and a few days in October last year because the Black River was not high enough to operate any of the three turbines.
The city uses the electricity it produces to power a few municipally owned buildings. Excess power is sold to National Grid for a profit. The city budgets annual revenues of $2.8 million from the electricity it sells.
"We fell short by about $648,000 of our projections because it was so dry last year," City Manager Mary M. Corriveau said.
Last week, the plant began operating all three turbines, Mrs. Corriveau said.
About 110,000 kilowatt hours per day are produced by the plant per hour while all the turbines are running.
The first 11 days this month, the plant produced 858,000 kwh, compared with the 6,003 produced in all of last August.
The city paid $105,507 to purchase electricity from National Grid in June and July last year. This year, National Grid handed over $149,545.91 to buy excess electricity the past two months.
Mrs. Corriveau was quick not to concede that the city is in better standing financially because of the additional money.
"With one-twelfth of the fiscal year through, we still need to see how things are going to end up," she said. "This is an uncontrolled revenue source driven by Mother Nature. We could see huge swings either way."
That revenue is coming from the wetter-than-average season the north country is experiencing.
Typically, 2.2 inches of rain falls during July in Watertown. More than 4.3 inches fell in the city last month. In June, 4.9 inches fell, compared with the 3.8 inches the city historically sees.
While localized runoffs contribute to the Black River, most of the water that is used to turn the turbines is picked up by the river farther south and east in the Adirondacks. Stillwater Reservoir also feeds the Black River and, during dry periods, supplies a third of the flows passing through Watertown.
The river was flowing at 7,070 cubic feet per second through the city Wednesday afternoon, according to the U.S. Geological Survey Web site. That is three times greater than the historical average.
At least 1,800 cfs must be flowing into Watertown to turn the turbines. The river hovered at 1,100 cfs for most of last summer. The Hudson River-Black River Regulating District controls outflow from the Stillwater Reservoir to maintain a flow of at least 1,000 cfs through the city.