The company that coordinates electricity on the massive power grid that includes South Jersey expects peak energy use this summer to increase about 1 percent, slightly lower than normal due to a sluggish economy.

PJM Interconnection, operator of a grid that includes 13 states and the District of Columbia, projects peak energy demand at 155,553 megawatts this year. One megawatt can power 1,000 homes.

Consumer spending, the labor market and business investment all factor into how the Valley Forge, Pa.-based company estimates the peak load — the amount of electricity needed to satisfy the moment of maximum power demand by users.

Historical usage data, weather projections and input from electric companies are also part of the estimate.

PJM says the economy and a November forecast by Moody’s Analytics — which cites uncertainty on private business investment and tax increases and spending cuts that took effect this year — pushed projected demand down slightly.

“It’s been a trend for the past few years that we’ve seen the impact of the sluggish economy on power use,” PJM spokeswoman Paula DuPont-Kidd said. “It filters down and has an effect on everything — power use by large customers like industrial customers as well as consumers and retailers and commercial industry.”

Mays Landing-based Atlantic City Electric has forecast that demand for its power will peak in July, at about 2,700 megawatts.

Last year, the regional peak hit about 2,800 megawatts on July 18, a day in which temperatures reached 101 degrees in Atlantic City. By comparison, the highest demand in April was about half that.

The grid operator said it has enough available power to meet summer highs, when air conditioners are cranked up and electricity demands are their highest of the year.

PJM said it has nearly 187,000 megawatts of installed electricity generation capacity. There is also 11,175 megawatts available through volunteer programs in which customers are paid to reduce energy use on request at peak times.

Atlantic City Electric, a subsidiary of Pepco Holdings Inc., has a similar program, called Energy Wise Rewards, for customers who volunteer to have their central air conditioners cycled off and on at high-demand times.

Atlantic City Elec-tric’s website says air conditioner fans continue to operate during these times, usually resulting in a 1- to 3-degree temperature rise during the power conservation period.

The utility’s summer peak load is projected to increase at an annual rate of 1.1 percent over the next 10 years, PJM estimates.

July is typically the month when the grid is most stressed. It is during these times when electricity can be more expensive, when more generators are called upon to produce energy.

“The simple laws of supply and demand,” DuPont-Kidd said. “When the demand is higher, supply typically becomes more expensive.”

Contact Brian Ianieri:

609-272-7253

Five years as Ocean County bureau chief, 12 years as regional news editor (not continuous), 10 years as copy editor (also not continuous), all at The Press of Atlantic City.