PECO Energy Company's Rate R-S allows you to interconnect with the electric grid without completing the same costly and detailed engineering studies that are required of large power producers. Further, when your system is producing more than you consume, this special tariff allows you to divert surplus electricity to the grid for future use. This works by:

1. Spinning your present meter backwards when you generate more electricity than you need, or
2. Through the installation of an additional meter that calculates the electricity you produce separate from the electricity you consume.

Net metering tariffs are significant improvements to the renewable energy industry. These tariffs, like PECO's Rate R-S allow you to receive the same rate for the energy you produce as the elecricity you use. The "old" rules would only offset your usage by the avoided cost, not the rate you pay.

Attempts are being made, both nationally and in Pennsylvania, to standardize tariffs on renewable and other distributed generation. The Institute of Electrical and Electronic Engineers (IEEE) continues to lead the efforts to standardize the technical requirements for utility photovoltaic interconnection across the country.