Almost three thousand Stawell homes and businesses were left without power on Wednesday night after damage to a power substation and at least two pole fires combined to cause headaches for residents, fire crews and power supplier Powercor.

The power pole fires were sparked after the first decent drop of rain in Stawell in almost a month. 4.6 millimetres of rain was recorded in the 24 hours to 9am yesterday.

The first power pole fire occurred on the Western Highway just before 10pm and was followed by another on the corner of Patrick and O'Regan Streets an hour later.

At its peak 2,751 customers were left without electricity. The majority of those saw a gradual restoration to their service between midnight and 1am Thursday morning.

Almost a quarter of those initially affected woke to find they were still in dark well into Thursday morning.

Powercor spokesman Lyall Johnson said about 512 customers are still awaiting a restoration of their service.

Mr Johnson said it was unclear of the exact cause of the damage to the substation but that it could have been caused by several things including a blown fuse.

Country Fire Authority District 16 Operations Manager Chris Eagle said volunteer fire crews attended both pole fires to monitor the situation before Powercor officials arrived on scene.

"This is just one of those things where after we have an extended spell of dry weather dust and debris accumulates on top of the insulators of power poles," he said.

"The cooler conditions meant there was moisture in the air and a shower of rain isn't enough to wash the dust and debris away but enough to cause the surrounding power lines to begin arcing and the power poles to catch fire."