PJM Interconnection may have lowered its forecasts for peak electricity load on the Virginia Peninsula, but the regional transmission organization still contends that the proposed Surry-Skiffes Creek high-voltage transmission line is still needed to avoid the risk of blackouts.
“It is PJM’s determination that the current Skiffes Creek 500 kV project remains the most effective and efficient solution to address the identified reliability criteria violations,” wrote Steven R. Herling, PJM vice president-planning, to the Norfolk district commander of the U.S. Army Corps of Engineers earlier this month.
Dominion Virginia Power, which must obtain a permit from the Corps before it can commence construction, has encountered stiff opposition to the project. Preservationists say the highly visible power line will disrupt views of the James River little changed since the first English settlers arrived more than 400 years ago.
The project was precipitated by federal clean-air regulations that compels Dominion to shut down two of its aging, coal-fired generators at the Yorktown Power Station. Those units are scheduled to go offline next month, eliminating a major source of electric power on the Peninsula. The region is served by multiple transmission lines that can meet electric power demand under routine conditions. But the Peninsula grid lacks the redundancy to meet federal reliability guidelines designed to prevent another cascading blackout like the one that plunged 55 million in the Northeast and Canada into darkness.
Dominion selected the Surry-Skiffes route after examining numerous alternatives. Foes charged that the utility considered only a narrow range of options. Instead of building a 500 kV line across the James, it could have met reliability standards through a combination of measures: upgrade of existing lines, solar power, energy efficiency, demand-response, greater reliance upon the oil-powered Yorktown 3 unit, and/or building a less obtrusive, lower-voltage line across the James. Arguing that the 500 kV line was overkill, they also argued that Dominion forecasts for electricity demand were unrealistically high.
In October 2016, the National Trust for Historic Preservation, which has named the James River as one of the nation’s 11 most endangered historic places, published an alternatives report prepared by Richard D. Tabors, a consultant and former MIT professor. Using Dominion data and the same simulation model as PJM, Tabors outlined four alternatives.
Tabors recommended upgrading existing 115 kV and 230 kV power lines feeding the Peninsula, getting greater use out of the Yorktown No. 3 oil-based generator, dropping load at selected feeders, and building new transmission lines, preferably along existing rights of way. Each scenario, states the report, “is generally less costly and can be implemented in a shorter period of time.”
Since publication of the Tabors report, PJM has backed off its earlier load forecasts. Reports David Ress with the Daily Press:
The latest PJM forecasts … suggest peak load demand during the summer would grow at an annual rate of 4 percent though 2027, to reach a total of 20,501 megawatts.
That’s 1,755 megawatts less than PJM’s forecast a year ago, nearly an 8 percent decline. Last year, Dominion’s summer peak was 19,539 megawatts.
But in Herling’s letter to the Corps, PJM stuck to its guns on the larger point, that the Surry-Skiffes line presented the optimum solution to the Peninsula’s needs. “PJM staff has reviewed the proposed alternatives and found that none of them resolved the identified reliability criteria violations that are being addressed by the Surry-Skiffes 500 kV project,” wrote Herling.
There are multiple, inter-related reliability violations, said the PJM planner.
Solving for a single violation does not address the panoply of reliability violations that are designed to be addressed through the Skiffes Creek project. For example, the continued operation of the Yorktown 3 generator as proposed by Dr. Tabors would not address thermal overload and voltage violations on the 230 kV and 115 kV bulk electric system that were identified by PJM. In addition, Dr. Tabors’ reliance on the Yorktown 3 generator as a solution ignores the significant environmental operating restrictions and limitations on plant operations associated with that plant.
Subsequent studies have re-confirmed the need for the Surry-Skiffes project even considering PJM’s updated load forecasts, Herling wrote.
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