The Western Interconnection Regional Advisory Body told the Federal Energy Regulatory Commission on Feb. 23 about a number of grid reliability issues related to the U.S. EPA’s proposed Clean Power Plan, which would cut CO2 emissions from existing power plants by 30% by 2030.
FERC is in the middle of a review of the Clean Power Plan, which is due out in final form this summer, and is taking input from various parties on the plan’s potential impact on grid reliability.
Together with the Western State-Provincial Steering Committee and the Committee for Regional Electricity Power Cooperation, the Western Interconnection Regional Advisory Body (WIRAB) said it has been deeply involved in analyzing and promoting solutions to the reliability and operational challenges and opportunities posed by the changing mix of generating resources in the West towards more variable renewable generation, more natural gas-fired generation, and fewer coal-fired power plants. WIRAB was created by western U.S. governors under Section 215 of the Federal Power Act. Members of WIRAB represent the governors of 14 western states, the Canadian provinces of Alberta and British Columbia, and Mexico.
“Our observations are from an interconnection-wide perspective,” the filing noted. “Several Western states (e.g., Arizona and Montana) have indicated that coal plant retirements can result in local frequency and transient stability concerns. WIRAB staff encourages [the Western Electricity Coordinating Council] and the Order 1000 Regional Planning Groups in the West to conduct rigorous and transparent studies of potential local reliability issues. FERC should encourage these entities to work with Western states to quickly complete thorough and transparent analyses of these concerns. Similarly, we encourage these entities to consider in their studies the time available under the rule for expansion of natural gas infrastructure.”
WIRAB staff offered their observations on the impact of the proposed 111(d) rule on resource adequacy and grid reliability in the West:
- The timing of the emission reductions required to meet the EPA’s proposed interim goals in 2020 raise concerns about the pace of infrastructure expansion in the West. As long as EPA allows sufficient time for capacity expansion and the resource pathways for states and utilities are viable, 111(d) does not pose a significant risk to the ability of electric systems in the West to maintain reasonable capacity reserve margins that exceed expected peak demand.
- Continued growth of natural gas pipeline infrastructure will be needed in order to meet the incremental demand for natural gas created from retiring or converting coal plants. As long as the EPA allows sufficient time for pipeline expansion, the natural gas infrastructure in the West should be able to meet both the demands of new natural gas-fired electric generators and residential, commercial, and industrial end-users of natural gas. Consultants developed a High Coal Retirement Case to investigate whether a large and sudden increase in the total volume of natural gas demand by the electric sector will strain the physical capability of the existing pipeline systems in the West. The case modeled the retirement of 22,976 MW of coal plant capacity in the Western Interconnection; a 58% reduction relative to installed capacity in 2010. All of the retired coal capacity was assumed to be replaced with an equivalent amount of natural gas capacity at the same location.
- Regional coordination between electric system balancing authorities is leading to better use of the flexibility of existing generating resources to meet the ramping and balancing requirements associated with the addition of renewable energy resources. A recent study indicates that it is technically feasible for natural gas pipelines to meet the variable gas demands needed to integrate high penetrations of renewable resources under extreme winter load conditions. The study encourages FERC to continue to explore refinements to the nominations and scheduling process to facilitate gas system operations and to establish reliable communications between gas and electric system operators.
- WIRAB’s understanding of whether the Western grid will remain reliable as the power business moves to more renewables and natural gas plants and fewer coal-fired plants is incomplete. Recent studies show the industry should be able to maintain the frequency and transient stability of the system if the resource mix in the West changes significantly but more analysis is needed.
- Regardless of the 111(d) rule, the resource mix in the West is changing. The changing mix poses both reliability and operational challenges and opportunities that should be thoroughly studied and acted upon. The West is moving to an energy landscape that features far more variable renewable energy generation, more distribution generation, more storage and demand response, more natural gas generation, and less coal-fired generation. Regardless of the 111(d) rule, the involved parties must continue to pursue and enact reforms to increase system flexibility at the lowest cost, maximize the capacity and capacity utilization of the grid, and invest in technologies and mitigation measures that will enhance the reliability of the western grid.