By William Opalka

The Environmental Protection Agency’s proposed Clean Power Plan threatens system reliability in New York City due to the city’s frequent dependence on local oil-fueled generators, NYISO said.

NYISO also said the plan fails to recognize significant progress that New York state has already made in reducing CO₂ emissions.

But the majority of its comments filed with the EPA highlighted the unique circumstances of the largest city in the United States: a densely populated area with inadequate transmission capacity to move electricity from other regions of the state, forcing it to rely on smaller units within city limits that are often fueled by oil.

“A majority of the electric capacity within New York City is dual-fuel oil/gas steam-fired electric generating units. These units are critically important, both due to their location within the transmission constrained New York City area and because they possess dual-fuel capability that provides a needed measure of protection against disruptions in the natural gas supply system,” NYISO said in comments filed with the EPA.

The units run principally on natural gas but can switch to oil when supplies are constrained. That dual capability was crucial last winter when natural gas supplies in the Northeast became constrained during the worst cold snaps.

Building Blocks

NYISO said the so-called “building blocks” in the EPA’s plan wrongly assume that output from these facilities could be reduced by more than 99%. Reliability would be compromised under the timeline contemplated by the plan, according to NYISO.

NYISO’s recommendations include:

• A review of reliability impacts using a preliminary assessment already done by the North American Electric Reliability Corp. The Federal Energy Regulatory Commission also should be involved in this review to assess both the reliability and other issues that fall within its jurisdiction.
• Formalization of a reliability “safety valve” by which the implementation of a state plan could be adjusted, with new time frames that may be caused by unforeseen circumstances.
• Adjustments to the building blocks to produce a target that accurately reflects how power is generated, transmitted and used in New York. This would include elimination of the heat-rate improvements assumed in building block 1.
• EPA adoption of a rate-to-mass conversion method that supports regional efforts, like the Regional Greenhouse Gas Initiative, that harness market forces.

The grid operator also said New York has not been given credit for emissions reductions already achieved or for its plans to further reduce carbon emissions.

“New York has already reduced CO₂ emissions from its power sector by 41.6% below 2005 levels and generates approximately 53% of the electricity it uses on an annual basis from non-emitting resources,” NYISO said.

Its commitment under the nine-state Regional Greenhouse Gas Initiative calls for further carbon reductions by 2020.