Electricity prices generally reflect the cost to build, finance, maintain, and operate power plants and the electricity grid. It does not mean that if there is more people it will cost more or less. There has been cases in UK where the government couldn't keep up with the maintenance of their coal power plants because the government was in bad shape, so they jacked up the prices for the consumers. You can't just say because there is more people living in one area the electricity bill will be higher, the only reason the bill is higher is due to the government wanting it to be high.
I think you should watch this, Obama says something cool, how his cap and trade system will make your electricity bill higher.
https://www.youtube.com/watch?v=MiqM06fqt-g