New England’s power system is strong, but the changing resource mix, driven by industry trends and state policies, is making operations more complex, according to a Feb. 20 briefing on the state of the region’s grid by Gordon van Welie, president and CEO of ISO New England Inc. Nuclear, oil, and coal-fired power plants that operate with stored fuel are retiring, and are being replaced by natural-gas-fired plants that rely on timely fuel deliveries and renewable generation that is weather-dependent. As the power generation fleet moves towards a mix of energy-limited resources, the ISO said that fuel security may become a year-round concern.

State policies to attain their clean energy goals and mandates have created a need adapt markets, increasing the complexities in maintaining competitiveness while accommodating public policy goals, the report said. The concerns come amid multiple efforts and market rules to address these challenges. Last year, the ISO implemented market rules to accommodate entry of state-sponsored resources, becoming the first regional grid operator to create a market mechanism to protect competitive pricing in the capacity market while accommodating state policies. The grid operator has also developed interim rules to delay retirements that could increase fuel security risk, while it is developing a new market-based mechanism to place a value on energy security.