Retailers Include: AEP Energy , APG&E Energy Solutions , Calpine Energy Solutions , Constellations NewEnergy, INC , Crius Energy , Direct Energy Services LLC , Dynegy , ENGIE Resources , Entrust Energy , IGS Energy , Just Energy , Liberty Power , Next Era Energy Services , Nordic Energy Services, LLC , NRG Energy INC , Source Energy , Spark Energy , Starion Energy , Stream Energy , Talen Energy , TransCanada Power Marketing LTD. 
Variable-rate supply plans, as the name suggests, have a rate that varies based on the market price of electricity. Seasonal and market fluctuations can affect supply rates. While variable-rate supply plans can allow you to take advantage of market-price lows, there is the possibility of paying for high supply rates when demand is at its peak. These plans offer great flexibility.
Just as you shop for other products and services, you may also be able to shop for an energy supplier. With choice, energy customers from large manufacturers to residential homeowners are able to shop for energy options from a diverse group of competitive suppliers certified by the Public Utilities Commission of Ohio (PUCO). As more suppliers are offering their services in your area, you have the opportunity to choose the company that supplies the generation of your electricity and supplies your natural gas.
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.