This is inspiring me to finally deal with changing electricity suppliers, since I'm in Pennsylvania too. Currently I just buy from my default supplier, PPL.
The customer charge is $14.13 a month - fixed - and the effective price per kWh is 13 cents. I used all of 222 kWh last month so electricity isn't that big of a deal for me. But I will pay more in the winter because we have electric heat in our finished attic which is where our daughter plays in the winter. We bought a portable a/c that also can use its heat pump to heat this summer, so I'll try to see if that's cheaper to run than the electric heat.
So, going with looking for a fixed rate around the New Year means that like MrSal I should hit a three-month contract. Picking the cheapest would save me 3.3 cents/kWh or, estimating high bills (300 kWh), $10/month. It's not negligible but it's not huge either.
I also looked into a power purchase agreement with SolarCity. Their offers are 15 cents/kWh for the next 20 years, or 12 cents/kWh increasing by 2.9%/year for the next 20 years. Either of those would mean never worrying about it, and rooftop solar is cool. But it wouldn't cover my whole electricity bill and it's not a ton of savings. One could try to Nostradamus it and say that mandated renewable percentages will increase electricity prices going forward, but that's a lot like market timing to me.