Still, we like that if you choose to re-up with FirstEnergy again at the end of your initial term, you won’t have to worry whether you’re enrolling at an expensive time of year. First, since it offers just two options, constant for years, its prices are set with the long haul in mind. Second, since the electricity grid in Pennsylvania is more taxed during winter than any other season (space heating accounts for 50 percent of household electricity consumption in PA; air conditioning just three percent), signing up in summer means prices won’t be temporarily inflated.
A feed-in tariff (FIT) is an energy-supply policy that supports the development of renewable power generation. FITs give financial benefits to renewable power producers. In the United States, FIT policies guarantee that eligible renewable generators will have their electricity purchased by their utility.[2] The FIT contract contains a guaranteed period of time (usually 15–20 years) that payments in dollars per kilowatt hour ($/kWh) will be made for the full output of the system.
The two most common distinctions between customer classes are load size and usage profile. In many cases, time-of-use (TOU) and load factor are more significant factors than load size. Contribution to peak-load is an extremely important factor in determining customer rate class. Consumer loads may be characterized as peak, off-peak, baseload, and seasonal. Utilities rate each load differently, because each has different implications for a power system.
The utility – or local distribution company – owns and operates the way electricity or natural gas is delivered to homes and businesses. The infrastructure that brings energy to homes, businesses and industrial facilities is owned by the traditional utility company. While your local utility reads your usage meter and bills you on a monthly basis, the transmission and distribution charges are set by regulators. 
Usually, fixed-rate renewable-energy plans are among the most expensive options. But in our research, we found Constellation’s green plan rates were comparable to its non-green versions. For example, out of two otherwise identical fixed-rate, 12-month plans from Constellation — “12 Month Fixed Rate 100% Green” and “12 Month Fixed Rate” — it’s the renewable version that currently costs less.
Maryland is among 15 states where electricity customers may choose their providers. It's called deregulation, but it might be less confusing to call it energy choice. Customers may select their electricity supplier - providers compete on price, term length, percentage of renewable energy and more. Electricity will continue to be delivered by a utility.
Over a year, you could save nearly $100 by choosing the green plan. But it’s important to note that Constellation’s attractive initial rates will very likely not be around for a second year. According to the customer reviews on Consumer Affairs, this new contract usually jacks up the price. It offers great rates for new customers, but it may not be worth it to stick with them for more than an initial contract.
Many homes across the UK have never changed their energy supplier, confining themselves to one provider without first considering their options- many of which may be cheaper. Ofgem, the regulator of the electricity and gas markets in Great Britain, estimated that only 38% of homes have ever changed their energy provider. This means that more than half of British homes have not looked into the huge amount of options available to them on the energy market.
 1.     Contracts:  Before, there were no contracts.  You signed up or you didn’t.  When it’s the only game in town, you have to play by their rules.  Nowadays, you’ll see these ultra-fabulous rates bandied about but it’s only by carefully scrutinizing the fine print that you’ll discover those wonderful rates come with a one-year lock-down or other catches.