This time series graph shows a comparison in electricity rates between four different plan options in the deregulated energy market in Pittsburgh, Pennsylvania. ESCOs give you the option to switch electricity from distributors such as Duquesne, and customers have an option to choose between fixed term or variable rate plans. A fixed term plan entails a standard rate for a "fixed" period of time - 6 months, 1 year, or 2 year (some ESCOs have recently started a 3 year fixed plan, but not enough data was present to draw any conclusion). Variable entails a possible month to month change in rate.
Here I have graphed the average rates for 6 month, 1 year, and 2 year fixed plans over time against both the average variable rate and against Duquesne's price to compare. The inclusive dataset ranges from September 2010 to July 2013. The three fixed rates (in gradients of blue) are competitive to both the average variable rate and Duquesne's price to compare. On average, a 2 year plan is cheaper than a 1 year plan, which is cheaper than a 6 month plan. While a customer may have to sign on for a longer period (and their may be a cancellation fee if a customer decides to leave the plan early), he or she did historically get a cheaper rate.
Finally, while the variable rate may, on average, be more expensive than the fixed rate plans, it is also competitive to Duquesne's price to compare.
At WattBuy.com, you can find more in-depth information on energy suppliers and electricity rate comparisons, including introductory rates, cancellation costs, and renewable energy plans.