The theft of copper cables from electricity sub-stations has tripled across the Central Network's region.
More than 50,000 Midlands customers were left without power due to thefts and two people have been killed.
Power-supplier Central Networks has joined forces with Crimestoppers, offering a £1,000 reward for information leading to a conviction.
Customer operations manager for Central Networks Phil Wilson said thieves were running a needless risk.
He said: "Clearly they're able to get some cash for the copper, we would argue that ... they shouldn't do it and they shouldn't be there.
"(They're) clearly causing great inconvenience for customers who have to go off supply and putting themselves in danger and also our staff in danger when we have to go back into the sub-station to make it safe"