U.S. tax credit sought for improved 140.4-MW Comerford

Hydropower operator TransCanada is asking the Federal Energy Regulatory Commission to certify efficiency improvements at its 140.4-MW Comerford hydroelectric plant in New Hampshire as eligible for renewable energy production tax credits.

The Energy Policy Act of 2005 amended the Internal Revenue Code to apply a production tax credit to incremental production gains from efficiency improvements or capacity additions to existing hydropower facilities placed in service after Aug. 8, 2005, and before Jan. 1, 2014. (HydroWorld 2/14/09) The Internal Revenue Service determines whether to grant the credits after FERC certifies hydropower production. FERC has certified incremental generation for more than three dozen hydro projects since August 2005. (HydroWorld 5/30/09)

TransCanada unit TransCanada Hydro Northeast Inc. applied to FERC July 3, 2009, seeking PTC certification of incremental gains in generation resulting from replacement if its Unit 1 turbine runner at Comerford, one of three developments in the 291.36-MW Fifteen Mile Falls hydroelectric project (No. 2077) on the Connecticut River in New Hampshire and Vermont. (HydroWorld 1/2/09)

In 2006, TransCanada applied to amend its hydropower project license to allow replacement of the four turbine runners at Comerford with more efficient units designed to harness power from three seasonal minimum flows that were newly required by a FERC relicense in 2002. It received approval to replace units in two phases, Unit 1 in the first phase, and Units 2-4 in a yet-to-be-completed second phase.

TransCanada said an analysis of Unit 1 since new runner installation in 2007 reveals an anticipated average annual generation increase of 18,009 MWh, representing a 4.9 percent generation gain at Comerford.

“The new runner provides significant additional energy during periods when only minimum flow is generated and the remaining units are shut down,” the application said. “The new more efficient runner (at lower flows) provides new opportunities to generate at higher efficiencies in the intermediate stages between successive units being dispatched. Therefore the total energy gain is a function of additional energy from operating Unit 1 during minimum flow periods plus operating it at various stages as additional units are brought on line.”

To calculate the incremental generation, TransCanada was required to develop a model of a historical generation baseline for the original unit. It could not use actual past generation because the new minimum flow requirement did not exist historically and Comerford had been operated for system support or load control, resulting in less than optimal generation.

Actual historic generation averaged 363,775 MWh per year compared to the model historical baseline average of 370,016 MWh, had the minimum flows been in effect historically. Model generation for the improved unit was 388,025 MWh annually, for incremental improvement of 19,009 MWh, or 4.9 percent.

Previous articleAlstom Hydro to equip India’s 500-MW Teesta 6
Next articleTurkish bank courts private renewables projects, including hydro

No posts to display