PJM Interconnection is making changes to its planning process as the economy, generation retirements and additions, and demand response have wreaked havoc on load forecasting, said Steve Herling, PJM’s vice president of planning.
“It really is making it difficult for us to know what the system will look like at any point in time over the next five years,” he said at EEI’s Transmission, Distribution & Metering conference in Dallas Oct. 10.
Because the load forecast has been in such a state of flux for the past few years, PJM has had to move projects back to the point where a couple have been suspended, he said. Until the recession, load forecasts would move about a tenth of a percent. “Suddenly it dropped like a stone, and projects were being delayed by years,” he said.
Generation retirements as a result of various regulations are the biggest unknown and pose the biggest challenge to a long-term outlook, he said. PJM usually receives notice of a year to a year-and-a-half in advance of generation shutting down, but can receive notice only 90 days in advance. PJM’s planning process is 15 years.
“If we start dropping units off 12 months, 18 months out, a lot of the planning we’ve done is now very quickly needing to be re-looked at,” Herling said.
To better model for transmission needs, PJM will develop an internal list of generators that are most at risk of being retired, but will likely need to revisit that analysis on an annual basis.
“We know we have a risk of thousands upon thousands of megawatts that could be retiring,” Herling said. “We should be looking at scenarios to see where do the most robust transmission upgrades fall, where are the opportunities to satisfy public policy goals around renewables, and, for that matter, look at where we can reduce congestion on the transmission system.”
In eastern PJM, there are 7,000 MW and in the mid-Atlantic region of PJM there are 9,500 MW of once-through cooling coal units.
“A lot of this stuff could be very much at risk of shutting down, so anything that happens in this area needs to be factored into the analysis we’re doing, on top of uncertainty around demand response and load forecasting,” Herling said.
He noted that in addition to the load forecast dropping, growth was “tailing away,” which also has a significant impact on a long-term outlook.