Electricity use cools down as temperatures rise

Credit: Mike Conner/UOS

Typically when the temperature spikes, so does energy use. It’s pretty simple. Pulling heat and humidity out of buildings, offices, and classrooms – thus making them comfortable to occupy – requires a vast amount of energy. That’s why on July 6th Engineering and Utilities (E&U) declared a Demand Management Day, and the University’s response was remarkable.

Until that point, the 6th was predicted to be one of the hottest days of the summer, and the forecast was correct. The mercury swelled to 100°F at Logan Airport - it was even warmer inland. Since electricity rates are often based on peak usage, E&U sent a message to schools and departments asking that they reduce their energy use wherever and whenever possible. The end result was a University-wide 7% decrease in energy consumption – or enough electricity to power about 900 homes—and significant cost savings for Harvard.

How did schools and departments do it? Many of the steps were quite simple such as shutting off non-essential lights, raising air conditioning set points, and closing window shades. Signs were also posted in many buildings alerting staff about the conservation effort. “This year, the message certainly filtered down from the building operators to the building occupants,” said E&U Associate Director of Operations Bob Manning. “An event like this is always more successful when the occupants are involved.” Other conservation measures were more sophisticated. Many building managers used the Siemens automation system to adjust energy use on a broader scale.

You may be asking yourself, why doesn’t the University do this all the time? “Since these events don’t happen on a regular basis, they really get attention,” said Associate Director of Energy Supply and Utility Administration Mary Smith. “Plus, on the 6th, some people probably set their air conditioning units a bit above a level that was comfortable. So to do that on a daily basis just isn’t practical. But it really highlights the need for everyone to strike a better balance between comfort and environmental responsibility.”

Depending on the weather, there may be additional Demand Management Days this summer.