US grid reliability agency analyzes CO2 cut plan

OREANDA-NEWS. The agency setting US electric grid reliability standards is offering new criticism of the assumptions underlying the federal proposal to cut CO2 emissions from the US power sector.

The North American Electric Reliability Corp. (NERC) in November had already released a high-level critique of assumptions and targets the Environmental Protection Agency (EPA) used in preparing the Clean Power Plan proposal that aims to cut CO2 emissions from the US power sector by 30pc by 2030 from 2005 levels.

Another study, expected to be released in March, will offer more detailed analysis of assumptions used in the proposal, NERC vice president and director of reliability assessment and performance analysis Tom Burgess said today during a discussion hosted by consultancy ICF International in Washington, DC. NERC also plans to finalize its assessment of the plan in two more studies, one expected after EPA completes work on the Clean Power Plan this summer and another in 2016 when states start crafting implementation plans.

"We are not advocating a specific position or policy" for the US power grid, Burgess said. But the reliability watchdog is pointing out that the proposal and other recent EPA rules will force a massive shift in the US generating fuel mix, with serious impacts on grid management and reliability maintenance techniques. NERC estimates that 700GW of capacity will be affected by the Clean Power Plan, although only a fraction of that capacity will have to shut down.

Three separate, sparsely connected "interconnections" — integrated grids — cover the continental US, incorporating multiple balancing areas and scheduling coordinators. None precisely matches state jurisdictions.

By contrast, the EPA proposal allocates CO2 emission targets by state and will rely on state implementation plans, although states may choose to craft compliance plans on a regional level.

NERC has not offered formal comments on the Clean Power Plan but hopes that its findings will inform decision-makers at state and federal levels. There was "limited outreach" from EPA to NERC before the proposal was released and while it is being finalized, Burgess said.

EPA has said it worked with regional grid operators, state regulators and other federal and state agencies to make sure that "environmental requirements remain compatible with maintaining electric reliability."

Burgess today singled out the energy efficiency assumptions behind the EPA proposal as the most worrisome in terms of assessing reliability impacts. Energy efficiency is one of the "building blocks," or proposed methods, that states can use to enforce the proposed CO2 emission cuts.

EPA assumes that demand-side energy efficiency can reach 1.5pc/yr but that target is 10 times more than "what we are seeing in terms of energy efficiency programs implemented by states," Burgess said.

The assumption that energy efficiency resources can offset demand growth also has serious ramifications for determining "how much generation we need in which category," he said.