Norwich — Norwich Public Utilities renewed its call for customers to conserve energy during this week’s high heat and humidity to reduce power demand during peak periods, which would help lower the year-round cost of electricity.

A portion of NPU’s annual costs for electricity is based on peak demand days, which included Monday, based on forecasts from ISO-New England.

“By using energy efficiently this week, customers can help keep overall electric costs, for NPU and themselves, lower throughout the year,” NPU said in a news release Monday.

Reducing energy usage during peak demand times also would reduce the wear and tear on NPU’s system, allowing critical equipment to cool down faster in the early evening hours, helping to improve overall reliability, NPU officials said.

“We are encouraging our customers to work with us while helping themselves during this challenging stretch of weather,” NPU General Manager Chris LaRose said. “By using energy wisely, our customers can help us keep costs low in the months ahead while reducing the likelihood of power outages this week.”

NPU is requesting that customers conserve electricity this week with steps that have little or no impact on their comfort.

Only run window air conditioners when someone is home and set AC systems to 73 degrees.

Wait until after 7 p.m. to run major appliances such as dishwashers and clothes dryers, and minimize use of heat-generating appliances, such as computers, curling irons, hairdryers and TVs before 7 p.m.

Avoid using the oven. Use the stove, microwave or grill outside.

Install energy efficient lighting. Only about 10-15% of the electricity that incandescent lights use results in light, with the rest turned to heat. Install window coverings to minimize heat entering a home or business.

“As always, we ask that everyone to keep an eye out for those who may have a tough time in extreme weather — particularly the elderly or infirm — to make sure everyone stays safe during this challenging stretch of weather,” LaRose said.