Madison heat wave leaves power grids bracing for demand surge - The Capital Times

Madison heat wave leaves power grids bracing for demand surge | News | captimes.com

Temperatures in Madison rose into the high 90s Wednesday as Dane County was hit with another heat wave.

The National Weather Service issued an excessive heat warning for much of central and southern Wisconsin through 7 p.m. Thursday evening as temperatures in Madison crept up to a high of 98 degrees and the city’s heat index reached 117 degrees Wednesday afternoon. In response, energy companies in the area are taking precautions to prevent power shortages as demand for energy to cool homes and businesses spikes.

Steve Schultz, spokesperson for Madison Gas & Electric, which provides much of Dane County’s electric and natural gas services, told the Cap Times energy use is at its highest during summer heat waves like this one.

“Electric use peaks during stretches of hot, humid days when air conditioners run in a majority of households and businesses,” Schultz said in an email. “This puts pressure on the electric grid.”

Heat waves also put pressure on electrical grids in another way, according to Line Roald, a professor at the University of Wisconsin-Madison’s Department of Electrical and Computer Engineering. Many of the generators that produce the electricity must be cooled to a specific temperature to generate electricity more efficiently, and extreme heat reduces the amount of electricity the generators can produce.

“When the grid comes into a squeeze is when we need a lot of electricity for cooling, but then the generators that also need cooling are not able to produce as much generated electricity as they otherwise could,” Roald said.

Energy use is expected to be highest Wednesday and Thursday, which are both expected to hit highs near 100 degrees, Schultz said. Demand will fall again as temperatures cool down into the mid-70s over the weekend, but in the meantime, the National Weather Service advises residents to remain in air-conditioned indoor spaces and drink lots of fluids to stay safe.

Alliant Energy, which provides energy to much of Wisconsin and Iowa, is also experiencing a spike in demand, according to spokesperson Melissa McCarville. But the company expects to “have sufficient resources available so that we can continually deliver the energy that our customers need,” McCarville said.

“We design, engineer and construct our facilities to address all weather conditions, and our crews are always prepared to respond to any issues that may arise,” she said.

What these high temperatures will mean for residents’ energy bills “really depends,” MG&E’s Schultz said.

“Energy usage has the biggest impact on a customer's bill and every house, apartment, business is different,” Schultz said. “Also, with the forecast calling for much milder temperatures by the weekend and next week, electric usage will likely be much lower and could potentially balance out the higher usage this week.”

MG&E is expected to have the capacity to provide enough energy to meet demand throughout the week, according to Schultz. Residents are encouraged to reduce energy use during peak hours — usually between 3 p.m. and 8 p.m. — whenever possible. Consumers can reduce their energy usage by raising their thermostat as high as is comfortable, waiting to run dishwashers or washing machines until after 8 p.m., closing blinds to keep rooms cooler and unplugging electronics when not in use.

Though building additional electricity generation capacity to keep the grid from experiencing greater stress on high-demand days is a possibility, UW’s Roald said doing so could become “unnecessarily expensive” to maintain when they are not in use for most of the year.

“Eventually, someone has to pay for those generators, and if they are only used during a short period of time in the year, that is not necessarily economical,” Roald said.

Both Alliant and MG&E also run energy-saving programs, in which customers can sign up to have their energy use reduced during peak demand hours in exchange for incentives.

“We are really encouraging our customers to be cognizant of their energy usage right now, and we hope that they'll utilize some of these energy efficiency tips,” said McCarville.

Climate change, renewable transition pose challenges for the grid

The Madison area is expected to see hotter summers due to the effects of climate change, according to WPR. That will pose a challenge for the region’s electric grids, which likely will experience more high-demand days.

Additionally, the ongoing transition to renewable energy sources from wind, solar and nuclear energy to power electrical grids may create problems for meeting demand on hot days, according to Roald, despite the necessity of leaving behind fossil fuels to mitigate the effects of climate change. Renewable energy sources such as wind and solar power may not be as reliable on days with little sun or wind, leaving higher levels of uncertainty about whether enough energy will be produced.

“We really, really, really need to see this shift to renewable energy happening in order to mitigate climate change,” Roald said. “But then at the same time, having more renewable energy means that it is more challenging to plan for heat waves and ensure that we will have enough generation capacity. So the grid also really has to do a lot of new thinking around how we’re going to be able to manage the impact of the extreme heat as it is now, but also other kinds of extreme weather.”

Roald said these challenges to electrical grids make residents’ energy consumption choices more important going forward.

“Consumers can really take a more active role there and sort of heed the warnings from their utilities and try to cooperate with the grid during times of stress,” she said. “That is actually going to be very important for us all to avoid having blackouts.”

“We can all do our little parts in trying to make the electricity grid continue to function well as this is unfolding,” Roald said.