The lights could dim over Unalaska this week as utility workers test out the city’s newest diesel generator.

The fourth engine will be switched on Wednesday at 12 p.m. Utility director Dan Winters says it will operate at a quarter of its full capacity before workers begin ramping up the load.

"So that could take a day," Winters says. "Or if we see any problems during that process, we’ll shut it down, fix any issues we may have and then bring it back up and start over where we left off at."

Winters says the tests should be done by the end of the week. To minimize the risk of a power outage in residential neighborhoods and schools, utility workers have reconfigured Unalaska's relay system.

"Right now, the industrial [zones on] East Point Road and Ballyhoo Road will go off first," Winters says. "That’s our big users. So hopefully that’s enough to where it won’t take down the rest of the town."

Once the generator's working at full blast, the city will be able to make an extra 4.4 megawatts of power -- about 30 percent more than the current capacity.

Adding the new generator cost about $7.6 million, with $2 million covered by state grants.