Bitcoin is a cryptocurrency and a digital payment system. The system is peer-to-peer, and transactions take place between users directly and immediately. The technology itself is a bit complicated, but think of it as a giant ledger that is constantly and instantly updated. Transactions are very fast and you do not need any bank acount or any other third party.
You need this speed on the electricity grid. Since you can not store electricity efficiently and economic, you should use it as soon as possbile. In this point cripto currencies come into play.
The system is not very complicated. What you mainly need is Smart Greed and a market platform. The cripto currencies will be the key to make this new economy work. On the market platform the electricity will be traded. The software will make sure energy flows do not exceed the physical wire capacity and the digital currency is exchanged only when the electricity is exchanged.