Prince Edward Islanders set a new record for peak electricity use in December, and Maritime Electric is trying to figure out why.

On Dec. 10 at about 6 p.m. Islanders were using 230 megawatts of power, seven megawatts more than the previous peak. Maritime Electric is trying to figure out why power use jumped, when the utility's message of using less seemed to be getting through to people.

"We know that Islanders can do it and we know that Islanders want to do it," said spokeswoman Kim Griffin.

The utility is working on a theory that people are using electric heating units to keep certain rooms or areas of their homes heated while turning down other forms of heat such as oil or propane, said Griffin.