Energy sellers must provide collateral to ERCOT to cover expected future costs of buying wholesale electricity and if the companies don’t have enough capital, they get shut down. Breeze Energy, a Dallas-based electricity retailer that sold wind-energy plans to 9,800 customers including many in the Houston area, got caught in that financial squeeze when it defaulted on its collateral obligations.
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.