With the region now into the second day of temperatures approaching 100 degrees, NSTAR is calling on customers to voluntarily conserve energy.

"NSTAR is prepared to meet the added electricity use brought about by the heat wave and we're asking our customers to take a few simple steps to help," said Werner Schweiger, NSTAR's Senior Vice President of Operations. "If customers collectively move their air conditioner thermostats up by just a few degrees, and shut off unneeded lights or appliances, it will help the entire region and they'll save money on their electric bills."

Schweiger added that late afternoon is the time of peak electrical use in the region and asked that customers pay particular attention to how they use electricity during that time.

The company is offering the following suggestions for smart home energy usage during the heat wave:

Create your own wind chill - Ceiling fans help make a room feel more comfortable and allow you to adjust your air conditioner thermostat for more energy savings. When humidity is high, set the fan speed on low for more comfort. Make sure to turn your fan off when you leave the room, though. A ceiling fan doesn't cool a room--it only cools you, through a wind-chill effect on the skin.

Keep air conditioners in the shade - An air conditioner operating in the shade uses as much as 10% less electricity than the same one operating in the sun. Avoid installing window units on the south side, or consider planting trees or shrubs to shade air conditioners but not to block the airflow.

Keep the heat out - Sometimes very simple acts can make a big difference. Sunlight shining in windows usually adds the largest amount of unwanted summer heat, which only creates more warm air to keep cool inside. Block daytime sun with blinds, shades or drapes. Be sure not to block the air conditioning unit with drapes or furniture.

Make the most of programmable thermostats and timers - Why pay to keep the house cool when you're not home? One of the most effective ways to reduce air conditioning costs is to set your programmable thermostat to 78 degrees or higher while you are out and then set it to automatically readjust to your preferred level an hour before you return. Built-in timers on room air conditioners also allow you to automatically control your home's temperature.

Size your air conditioning equipment correctly - Bigger isn't always better. Air conditioners that are too large fail to properly dehumidify the space, reducing comfort and costing more to operate. Proper sizing and installation are essential to maximize efficiency and performance, increasing your comfort and long-term savings.

Maintain cooling systems regularly - Properly maintaining equipment prevents future problems and added expenses. Qualified contractors can do annual pre-season check-ups to ensure that your central air conditioning is running as efficiently as possible.

Consider an upgrade - If your cooling system is more than 10 years old, consider upgrading to a new unit that has earned the EPA's ENERGY STAR for high efficiency. Qualifying room and central air conditioners use new technology that uses up to 20 percent less energy without sacrificing comfort. Look for units with the highest Energy Efficiency Ratios for greater savings.

To help customers better afford improving the efficiency of their homes, NSTAR offers great rebates and a new loan program for improvements recommended during an NSTAR-sponsored energy audit. For example:

-- No-interest or low-interest loans - up to $15,000 - toward energy efficiency upgrades including window replacements and heating systems

-- Up to $1,500 in rebates for insulation and air-sealing upgrades

-- $300 rebate for a high-efficiency central air conditioner or water heater

-- $150 for upgrading to a high-efficiency refrigerator

-- $100 rebate for a high-efficiency tumble washer

-- $25 rebate for programmable thermostats; $10 rebate per replacement window

-- Up to $500 in heating system rebates

NSTAR transmits and delivers electricity and natural gas to 1.4 million customers in Eastern and Central Massachusetts, including over one million electric customers in 81 communities and nearly 300,000 gas customers in 51 communities. For more information about NSTAR visit: www.nstaronline.com.