Price, of course. Prices are expressed in cents/kilowatt hour. Plan types include fixed rates and variable rates. Fixed rates offer consistency throughout the plan term, which can run from six to 36 months. Variable rates can change monthly - they're great when prices go down, but not-so-great when they don't. Finally, if you care about your carbon footprint, you may choose a plan sourced by solar or wind energy.
There are several reasons that some energy suppliers end up being cheaper than others. The largest energy companies, also known as the Big Six, often do not need to offer rates that are as competitive as smaller companies. This is because they are more recognisable names and therefore can always rely on a steady base of customers. You can avoid this and save money by switching to a cheaper provider.
But in future, BNEF argues, the aim will be to secure as low-cost renewable power as possible and supplement that with “more expensive flexible capacity from demand response, storage and gas, and then importing the remaining needs from neighbouring grids. We are reaching the point in the story where power system regulation will have to be fundamentally rethought .”