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.
Should you choose a short-term, long-term, month-to-month, or prepaid plan? The short answer: it depends on your specific needs. How long do you anticipate living at your location? Are you deciding in the peak season (summer in Houston) or off season? All electricity providers in Houston offer a broad selection of plans for different contract lengths. Many also offer month-to-month and prepaid electricity plans. The bottom line is that everyone’s needs are different and all contract term lengths offer advantages and disadvantages.

Here are my 2 cents about electric companies when shopping around for the best rates. Currently, the average cents/kWh in Houston is 10 cents, after speaking to a very helpful, very informative Green Mountain Energy representative. Although their rates are a little higher than my current rates, they have FANTASTIC customer service (which is almost worth it). The GME rep even recommended that I stick with what I am using now since it's cheaper.
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.