PJM Interconnection has been studying, with the help of GE Energy Consulting and other groups, the consequences of adding significantly more wind energy and solar energy to its transmission grid. The “headline result” of a preliminary report, presented to PJM stakeholders recently, is that the system could handle renewable power generation capacity at a 30 percent penetration rate in 2026.
Here is how EnergyWire summarized the preliminary results (may be gated):
The eastern Great Lakes and mid-Atlantic region could rely on wind and solar power for as much as 30 percent of their generation capacity without threatening electricity delivery with net benefits even after additional transmission lines and reserve resources are added, according to a preliminary study released by the PJM Interconnection, the region’s grid operator.
The study, by GE Energy Consulting, investigates several scenarios for additions of wind and solar generation to the PJM grid, which extends from New Jersey to northern Illinois. It calculates the amount of new transmission lines needed to deliver the renewable energy and the required backup generation to support the variable wind and solar power.
The main impacts it reports are lower emissions of pollutants and greenhouse gases; no power outages and minimal curtailment of renewable energy; lower systemwide energy production costs; and lower wholesale customer power costs with the additional wind and solar resources.
“Even at 30 percent penetration, results indicate that the PJM system can handle the additional renewable integration with sufficient reserves and transmission build out,” GE said.
GE Energy Consulting is one corporate unit in the General Electric family, other corporate units make and sell generation equipment including wind turbines, solar pv products, natural gas turbines, etc. We can probably assume that GE Energy Consulting had access to good information in preparing their analysis.
Scanning through the 149-slide presentation reveals a bit about what GE Energy Consulting understands concerning intermittent renewable generation. For example, slides 49-55 discussed the transmission additions needed under the various scenarios studied. Slide 15 summarized the added transmission costs, which ranged from $3.70 to $13.7 per MWh depending on scenario.
On the question of whether adding intermittent renewable generation increases reserves requirements, the report concludes at slide 67, “The study identified a need for an increase in the regulation requirement even in the lower wind penetration scenario (2% BAU), and the requirement would have noticeable increases for higher penetration levels.” Regulation, as the term is used in power systems, refers to a fast-responding reserves service that dispatchable generators can provide to the grid.
Power plant cycling costs are discussed at slides 78-93; the report indicates that adding renewable power results in more cycling operations for dispatchable power plants, higher cycling costs for dispatchable power plants, and less time spent operating in more efficient stable-output baseload conditions. Cost estimates for cycling range from $0 to as much as $21.90 per MWh of renewable output, depending on the scenario studied and the type of unit forced into additional cycling.
Power plant cycling emissions are discussed at slides 94-101; the report indicates that added cycling of fossil fuel plants does offset some of the emission reductions that might otherwise be expected from using wind energy or solar energy, but the effect is pretty small.
The report estimates the overall value of the renewable energy delivered to the system at about $50 per MWh.
The GE Energy Consulting analysis is interesting, in part, because of how their projections relate to my recently released report on wind energy cost estimates. I observed, among other things, that in addition to the costs of wind power capacity to project developers, there were other costs to be considered when evaluating wind energy in a policy context. Among the factors noted: transmission additions, grid-integration costs (mostly added reserves), some partial offsetting of renewable’s emission benefits due to increased cycling of dispatchable power plants, and added cycling costs imposed on the owners of these dispatchable units.
Michael Goggin of the American Wind Energy Association attacked my report on Into the Wind, the trade association’s blog, for “rely[ing] on obsolete data” and “regurgitat[ing] anti-wind myths that have already been debunked.” (I’ve responded to Goggin in a series of posts.)
I am now looking forward to Goggin’s attack on GE Energy Consulting for perpetuating these anti-wind myths.
NOTE: Here is Goggin’s actual reaction to the GE report, where instead of accusing GE Energy Consulting of failing to understand how the power grid operates, he chooses to accentuate the positive: “Independent grid operator study confirms wind power’s economic, environmental value.” (I guess it would have been awkward to complain too much about the report since GE Energy is an AWEA member.)