The heat isn’t over yet, particularly for power companies handling the first serious and widespread test of electricity generating marginal capacity of summer 2011.
The Southern and Midwestern parts of the US were still under the most severe temperature forecasts in the middle of the week, but temperatures north of 100 degrees Fahrenheit are set to sweep across the heavily populated Northeastern states on Thursday and Friday.
“The hot temperatures combined with high relative humidity will create dangerous heat indices well above 100 degrees over a large portion of the nation,” the National Weather Service warned in its latest update.
Northeastern US electricity grid operator PJM Interconnection said it had no steps that would affect customers planned for Wednesday, but warned that Thursday and Friday would be “big heat days.” Air conditioning stresses electricity grids far more than heating needs in much of the US, triggering spiking prices for transmission capacity, demand response events and straining an often aged generating and transmission system.
None of the electricity operating areas in the Northeastern US appear to be facing all-time peaks today, Constellation Energy senior vice president of demand response Gary Fromer told Breaking Energy. The summer peaks were expected around this time, Fromer said, allowing generators to prepare, and some cloud cover has spared PJM from needing to call for usage cutbacks, though the New York Independent System Operator had issued a day-ahead warning it might invoke its demand response programs.
After spending most of 2011 below $65 per 80 megawatt hours, prices for real-time delivery of PJM power on exchanges operated by CME Group have shot up to north of $71 for the same amount of electricity in trading this week, higher than any peak price for the same contract reached last summer.
Prices for very short-term delivery of power in PJM at some hours spiked even higher, as much as seven to eight times normal pricing, Fromer said.
Preparing for the Heat
Grid operators and their regulators conduct annual studies to guarantee they can have sufficient excess generating capacity to cover spikes in summer demand.
The Midwest transmission grid operator MISO said in late May it has reserve capacity of as much as 24% excess capacity available to meet summer demand, more than the 17.4% reserve requirement it imposes. The organization held a month-long series of readiness drills in May to test for spikes in power demand and the resulting emergency operating procedures.
At the national level, the North American Electric Reliability Council issues an annual summer reliability assessment, and said it expects excess capacity of 25.1% in the US and 35.8% in Canada should cushion electricity use spikes.
The group warned, though, that “prolonged hot weather” could contribute to regional shortfalls that would require “interruptible demands, voltage reductions, and public appeals” to handle. Limited demand growth overall, impacted by ongoing slow economic growth following the recent recession, could help keep electricity shortfalls contained.
Continued expansion of energy efficient equipment can also permanently drop electricity demand, Fromer said. With the deployment of smart meters that allow customers to see prices and potentially even get paid for not using electricity, the Constellation Energy’s demand response programs now have roughly 1700MW racked up in available load cuts that could be used to guarantee reliability.
Better Forecasting (And Management) Through Technology
Companies are using a variety of new IT tools and their ability to crunch historic weather data to make new and more-accurate forecasts of weather patterns that can strain the electricity system.
EarthRisk Technologies premiered its HeaRisk module system today, and said that its combination of historical weather data and proprietary algorithms can forecast heat waves up to 40 days in advance.
“Our success in predicting June’s heat wave and last year’s winter blast that severely crippled the East Coast impacting the entire United States is a testament to our unique ability to augment existing weather data with our own probability algorithms to foresee what most likely will occur down the road,” EarthRisk CEO John Plavan said in announcing the HeatRisk product. “This type of information is crucial to any industry where weather can have an adverse impact on operations.”
Photo Caption: Teenagers play in a fountain as temperatures soar to 40 degrees Celsius (104 degrees Farenheit) on June 27, 2011 in Lyon.