Sadly I think that not many power companies will start using BTC. The main thing here is that the only value that a company will get in accepting BTC is marketing value, not financial value. Starting to accept BTC will get your company free press and you will get new loyal customers from people who are loyal to BTC. But in financial terms, you are actually spending more then you did when you weren't accepting BTC.
I think that the big companies will stay away from BTC because the marketing value can also backfire. People who control most of the BTC aren't mostly known and the market system isn't very transparent. For instance if it would leak that even the biggest markets are presenting falsified data to stimulate trade, then BTC would be called an all out scam by the media. And when that happens then noone want's to be associated with BTC.

Thanks by standing behind me