1. After your contract ends, the energy company will send you a notification of your rate increasing to a variable rate (which usually translates to 2-3 cents higher/kWh by a certain date). They are supposed to notify you of this change. I've noticed as a customer, we get short-changed of one month from the contract rate (if you signed for 7 cents for 6 months, you'll only get that for 5 months). If you don't call, your rate goes up significantly if you don't call to change to a cheaper contract. Tell them you want the cheapest rate or you will cancel with their company.
In Houston, 0% of people have switched to a plan that has some renewable energy component to it. Another 0% have switched to a plan that is partially renewable, while 0% have switched to a plan that powers homes completely by renewable electricity. This of course means that 100% of people have remained on a plan powered by traditional sources of electricity such as coal or nuclear power.
Another unwelcome side effect of not knowing your average monthly kWh usage level is that you may end up paying more than you expect. This can occur when a customer inadvertently shops an electric rate based on a higher usage level than they actually use. Electricity suppliers commonly advertise their electric rates associated with the highest (2000 kWh) usage levels since those tend to be the lowest rates.
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.