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.