Does New Mix of Energy Resources Affect Grid Reliability?

Tom Johnson | April 3, 2017 | Energy & Environment
Operator of nation’s largest power grid reports increased reliance on natural gas and renewables is not adversely affecting sustainability

In a rapidly changing energy sector, are there still enough power plants available to provide the electricity everyone needs?

The operator of the nation’s largest power grid is answering that question in the affirmative. Its new study finds that with the addition of more natural-gas and renewable resources the system can remain reliable.

With the retirement of scores of coal plants and the early closing of some nuclear units, PJM Interconnection sought to determine whether the system is losing too many traditional resources in a new assessment, “PJM’s Evolving Resource Mix and System Reliability.’’

The study highlights some of the issues affecting the energy sector in New Jersey, which will see its two biggest coal units shut down later this year; its oldest-running nuclear plant, Oyster Creek, scheduled to shut down at the end of 2019; and questions raised about the economic viability of nuclear units elsewhere.

As elsewhere, at least five new natural-gas plants have either come on line or will soon be active, amid a rapid and controversial expansion of the gas pipeline infrastructure in the state. Amid all this activity, clean-energy advocates are pushing state policymakers to ramp up reliance on renewable sources of energy, such as solar and offshore wind.

In the 44-page study, PJM looked at the changing resource mix and significant penetration of renewables into the regional power grid, which stretches from the Eastern Seaboard to Illinois and serves more than 65 million people.

“We found that the risk to the system wasn’t that resources couldn’t necessarily provide reliability attributes but that the potential concentration of a single fuel source or low-probability, high-impact events could cause significant impacts to the system,’’ said Michael Bryson, vice president operations, who led the study.

“The study concluded that our current portfolio is both reliable and diverse,’’ Bryson said. “Going forward, we see significant more renewable energy and natural gas.’’

Perhaps the most striking finding of the study is its conclusion that a more diverse fuel portfolio is not necessarily more reliable. The report did not address the economics of various types of generation; factors that might affect a fuel’s deliverability; public-policy issues such as environmental impact, including the use of subsidies.

The issue of subsidies is becoming more controversial as states like New York and Illinois have handed them out to owners of nuclear units to make the plants more competitive. That issue also is emerging in New Jersey, although no specific proposal has been floated to give such incentives to nuclear units here.

The policy did arise during a question-and-answer period with reporters during a conference call on the study. “As we sit here today, it’s a state responsibility,’’ Bryson said, although he added PJM wanted to work with states to make sure energy markets are designed to correspond with those policies.

In a press release, PJM CEO Andy Ott also talked about working with stakeholders and the industry “to determine whether markets and operation structures need to shift to make sure that necessary levels of generator reliability characteristics are maintained in future resources mixes.’’