PJM could get 30% of its generation capacity from wind and solar power without harming reliability and while reducing prices, a preliminary study released last week concludes.
But owners of coal and combined cycle generators would face reduced run times and even lower prices than currently – even as their units suffer increased wear and tear from cycling to support renewables’ intermittency.
GE Energy Management, which conducted the study, outlined the preliminary results during a conference call last week. “Even at 30% penetration, results indicate that the PJM system can handle the additional renewable integration with sufficient reserves and transmission build out,” GE said. “…All the simulations of challenging days revealed successful operation of the PJM real-time market.”
Multiple Scenarios
The study looked at multiple scenarios for integrating increased wind and solar generation to the PJM grid. GE was charged with examining the operational, planning, and market effects of a large-scale integration of renewable power as well as what PJM will have to do to absorb it.
Current state requirements are expected to increase renewable generation to 14% of capacity, up from the current 2%.
The study estimated that increasing renewable capacity to 20% would require 820 miles of new transmission lines at a cost of $3.8 billion. Electric production costs would be cut by $9 billion annually, a 25% reduction, while carbon pollution would be cut by 80 million tons.
A 30% renewables goal would require 1,182 to 2,946 miles of new transmission costing $5 to $14 billion. Production costs would decrease by $13 billion (35%) per year and carbon emissions would decline by 140 to 200 million tons annually.
Increased Cycling, Reduced Revenue
GE predicts coal and combined cycle generation starts will increase and hours online will decrease, resulting in reduced net revenue and increased forced outage rates.
Combined cycle units perform most of the on/off cycling, seeing a 35% displacement relative to the business as usual scenario. Coal units perform load follow cycling, suffering an 18% displacement. The cost impacts would fall most heavily on combined cycle and supercritical units.
For examples, cycling costs for supercritical coal would increase from $0.66/MWh under the 14% RPS scenario to $2.22/MWh in the 30% “Low Offshore + Best Onshore” scenario, which envisions 228 GWh of wind and 48 GWh of solar.
Although on/off cycling and load-following ramps do increase emissions over steady state levels, emission levels do not change dramatically with higher levels of renewable generation.
Operational Impacts
The study found that higher penetrations of renewable energy would create significantly different operational patterns. “Although there were occasionally periods of reserve shortfalls and new patterns of combustion turbine usage, there were no instances of un-served load,” GE said.
Maximum regulation would increase from 2,000 MW for load only to approximately 3,000 to 4,000 MW in the 30% scenarios when 100,000 MW of new renewable capacity was added.
Diminishing Returns
The analysts concluded that expanding from 20% to 30% renewables “does not appear to be economically attractive.” GE will meet with PJM stakeholders to discuss the final report on Dec. 5.
