Variable Rate: With a variable rate, you stand closer to the fire. Rather than keep your costs separate from market conditions, you experience the rise and fall of price alongside your provider. You profit when supply exceeds demand, but could pay through the nose if the electricity grid becomes overtaxed. That usually means a higher bill in the summer and winter (when demand is at its highest) and a lower one in the fall and spring. A variable rate plan is best for people interested in staying on top of market changes – when prices get too exorbitant, there’s no contract and no cancellation fee if you want to try a new provider.
Depending on the state where you live, you’ll get your electricity bill from your local electric utility or your electricity provider.  Either way your electricity bill generally has two line items: supply and delivery. The supply charge is for the actual electricity used and this is paid to your electricity provider. The delivery charge is for the transmission and distribution of electricity and this is paid to your local electric utility.  In most states you will receive these charges on one bill, and the company that collects your payment will make sure that the appropriate parties are paid for their services.
That means that customers in Houston paid an average of $5,500 more for electricity over a 14-year time span beginning in 2002, according to the group that buys electricity on behalf of municipal governments in Texas. The calculation, which uses data from the U.S. Energy Information Administration, assumes monthly electricity use of 1,300 kilowatt hours.
One of the most common sticking points for electricity customers is what, exactly, the difference is between an electricity provider (also called REP, CRES, or electric supplier) and an electric utility (also called a TDSP, TDU, or EDU). They’re both vital to the success of electricity deregulation, but they play very different roles. Understanding how they fit together can make a big difference in your overall confidence as an electricity customer trying to shop for the best electricity plan.

On the other hand, month-to-month variable rate (no-contract) plans don’t have cancellation fees. You won’t be penalized if you find a better deal elsewhere and want to make another switch.  And, you won’t be stuck paying more than you should be if the market rate for electricity trends down.  But, if it goes up, you’ll be paying more than your in-contract neighbors, and you’ll likely want to shop around again for a better deal.
It’s worth noting that you can switch for free with no exit fee 42-49 days before the end of your contract. Under Ofgem’s standards of conduct, energy firms have to give you between 42 and 49 days’ notice of your tariff ending. You can use this time to decide whether to stick with them, or switch. If you decide to switch, you won’t be charged an exit fee.