A voltage reduction called for by the regional power pool ended Monday evening (5/20), but Pennsylvania Power & Light Co. urged customers to continue wise use of electricity during this unseasonably hot spell.

"Conditions on the power supply network returned to normal across the region Monday night," said John F. Sipics, PP&L's general manager for Power Systems Support, "but the power pool is projecting even higher levels of demand tomorrow (5/21), as the heat continues."

Demand by PP&L customers and on the Pennsylvania-New Jersey-Maryland Interconnection (PJM) came nowhere near summer records Monday. PJM did set a record for electricity use in the month of May. Demand on the power pool exceeded 41 million kilowatt-hours late in the afternoon.

PP&L is one of 11 member utilities of the PJM power pool, which coordinates the distribution of electricity to more than 22 million customers in a 50,000-square-mile area in Pennsylvania, New Jersey, Maryland, Delaware, Virginia and Washington, D.C.

Summer-like temperatures, combined with the fact that a number of large power plants are out of service for scheduled maintenance in preparation for expected high customer demand in the summer, have made for tight electricity supplies throughout the Northeast, Sipics noted.

PP&L customers can help the situation by using energy wisely and shifting the use of major electric appliances, such as washing machines, clothes dryers, dishwashers and electric stoves, to early morning or evening hours.

Other measures customers may take to save electricity are:

-- Set air conditioner thermostat at 80 degrees or use fans instead.

-- Block out the sun with drapes and shades to help keep homes cool.

-- Don't open refrigerator or freezer doors more than necessary.

-- Turn off TVs, radios or stereos when no one is watching or listening.

"Following these guidelines will help avoid possible power shortages, but people's primary concern should be their own health and safety during this period of extreme heat," Sipics said.

"We are not asking people to curtail the use of air conditioners, but to turn them off or raise the thermostat when they leave the house," he said. "Customers should use the electricity they need to avoid the adverse health effects of oppressive heat."

The power pool expects to be able to meet customer demands for electricity Tuesday. Should the situation worsen, however, PJM, through its member companies, such as PP&L, may have to take appropriate actions to reduce electricity demand. Those procedures could include reducing voltage, asking certain large industrial customer to curtail use, and making emergency appeals to the public for conservation.

"We will continue to update our customers on the status of power supplies," Sipics said.

Shortly after 3 p.m. Monday, PP&L and other PJM-member utilities reduced voltage on the electricity supply network to protect power reserves and continue emergency assistance to electric utilities in New York State. The voltage reduction ended at about 7 p.m.

Voltage is the amount of "pressure" sending electrical current along a power line. Reducing voltage is like reducing the pressure of water flowing through a garden hose. A voltage reduction has no lasting effects on appliances and other electrical devices.

PP&L supplies power to about 1.2 million customers in Central Eastern Pennsylvania.