The end of summer means that it's time for Texas electric customers to check their energy rate, and to see if they can save money by shopping around for an electric provider offering a lower rate.

Summer is typically a bad time to shop for a new electric rate, especially in Texas, because air conditioning demand strains the electric grid, causing the most expensive power plants ("peakers") to come online to meet this extra demand. This raises the price of electricity in the wholesale spot market, and eventually, this higher price works its way into the retail electric rate offered to customers.

That's why electric rates offered in the summer are higher, and why it's a bad time to shop for a new energy plan.

But now that summer weather is starting to ease, Texans are running their air conditioners less. The expensive peaking power plants don't need to be run anymore. With less demand, wholesale power prices moderate, as Texas enters the "shoulder" months of fall -- where there's no extreme demand on the grid from air conditioning use, like in the summer, or electric space heating use, like in the winter.

These shoulder months (spring and fall) are the best time to find the lowest electric rate, because the wholesale market trends to be the quietest at these times, meaning retail electric providers can offer you their lowest rates.

For example, in the Dallas/Fort Worth Metroplex (Oncor), electric rates, which had been at historic lows for over two years, started to creep back up towards 9¢ per kWh this summer, due to expectations of record demand, and a higher electric wholesale price cap.

However, with a relatively moderate summer, and the start of the fall shoulder months, electric rates in the Metroplex, and other areas of the state including Houston and Corpus Christi, have fallen.