The threat of price spikes have been long in the making, the result of changing economics of power production. The shale drilling boom produced record amounts of natural gas, which pushed prices to all-time lows and made gas-fired plants cheaper to operate than coal. Renewable energy such as wind is also producing abundant amounts of electricity at a lower cost than coal.
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.