The Sierra Club, as would be expected, on June 26 filed testimony with the New York State Public Service Commission supporting transmission-only alternatives to the impending retirement of the coal-fired Cayuga power plant.
Cayuga Operating Co. LLC, the plant’s owner, has offered to the commission several options centered on repowering the plant with natural gas.
The Sierra Club retained Pinewood Power Solutions LLC and PSM Consulting Inc. to look at the options, and they found that the transmission upgrades recommended by New York State Electric & Gas (NYSEG) are the best option and recommend rejection of the repowering alternatives proposed by Cayuga.
“The Sierra Club also recommends that the Commission require NYSEG to evaluate and implement, to the extent practicable, demand response and energy efficiency programs to alleviate potential operational or reliability concerns associated with Cayuga’s retirement during the time period before completion of the proposed transmission projects (mid-2017),” the club said. “In particular, consistent with the consultants’ analysis, Sierra Club urges the Commission to consider whether demand response can obviate the need for ongoing ratepayer subsidization of the near term operation of one of the two Cayuga units.”
In July 2012, Cayuga Operating filed notice with the commission of its intent to indefinitely mothball Cayuga no later than Jan. 16, 2013. In December 2012, the commission approved a Reliability Support Services Agreement (RSSA) between Cayuga and NYSEG through which NYSEG agreed to compensate Cayuga Operating in exchange for keeping the Cayuga facility online while transmission upgrades were made.
In a Jan. 18 order, the commission directed Cayuga Operating and NYSEG to compare the costs and benefits of two options: repowering Cayuga at its existing site or investing in long-term alternative transmission upgrades.
On Feb. 19, NYSEG submitted a list of two transmission projects to correct the reliability concerns raised long-term by the shutdown of Cayuga. The two projects are:
- Constructing a new 14.5-mile, 115-kV line from National Grid’s Elbridge Substation to NYSEG’s State Street Substation; and
- Rebuilding the existing 14.5-mile, 115-kV line from National Grid’s Elbridge Substation to NYSEG’s State Street Substation.
NYSEG has indicated that the two projects would be in service by mid-2017 and that after completion no electric generation will be required at the Cayuga facility to support the reliability needs of either NYSEG or National Grid.
On March 26, Cayuga Operating offered to the commission four repowering options:
- Option 1—repower the existing Cayuga units with natural gas for maximum combined output of 300 MW;
- Option 2—repower the facility with simple-cycle combustion turbine generators firing only natural gas with a maximum combined output of 294 MW;
- Option 3—repower Unit 1 with natural gas and Unit 2 with a combined cycle combustion turbine generator, a heat recovery steam generator (HRSG) and a condensing cycle steam turbine generator; and
- Option 4—repower the facility with a combined cycle combustion turbine generator, HRSG and a condensing cycle steam turbine generator.
On May 17, NYSEG recommended that the commission support implementation of the transmission upgrades solution rather than any of the repowering options identified by Cayuga.
The Sierra Club said in the June 26 testimony that it supports NYSEG’s two identified transmission projects and upgrades as the best long-term solutions to address long-term reliability issues associated with Cayuga’s retirement for several reasons. That includes that unlike Cayuga Operating’s repowering options, which present a number of reliability risks and, even if approved, would need to include the proposed transmission upgrades to address the identified overload issues, NYSEG’s transmission projects would fully and finally resolve reliability issues.
The existing Cayuga facility is a nominal two-unit station with a total site output of 300 MW (net). Coal is the original and base fuel of the existing plant. The plant entered commercial operation in 1955.