Since June, when the Environmental Protection Agency proposed its Clean Power Plan to limit carbon emissions from existing power plants, the name RGGI (pronounced "Reggie," short for the Regional Greenhouse Gas Initiative) has been floated as a tool for Pennsylvania to reduce its emissions and comply with the EPA's rule.

This is a logical move. The RGGI program - a voluntary market-based system for reducing power-plant carbon emissions in nine Northeastern states - has been successful in raising revenue to invest in efficiency, renewables, and other carbon-reduction activities. Carbon emissions in the RGGI region have decreased and revenue raised from the program has even been used to support state general funds.

So, why shouldn't Pennsylvania spend more time investigating RGGI as an option for Clean Power Plan compliance?

The bottom line is RGGI is not structured with Pennsylvania in mind. The commonwealth's electric-power profile and energy-resource industries are fundamentally different from the RGGI states. Pennsylvania ranks number three in the nation with respect to electricity generation. The commonwealth is an electricity exporter, meaning it generates more electricity than it uses and sells the rest, about 35 percent, to its neighbors.

In turn, Pennsylvania has a lot more carbon emissions than the rest of the RGGI states, plus the commonwealth has a robust fossil-fuel development industry not found in the Northeast states. At least four of the nine RGGI states regularly use more power than they generate from their power plants, meaning they have to import power from other states. The remainder of the RGGI states export very small amounts of power (measured in megawatt hours), compared with Pennsylvania.

Before the Clean Power Plan was conceived, Pennsylvania had rejected RGGI for a variety of reasons. Certainly, one reason was that many policymakers did not want to enter into a voluntary program to reduce carbon emissions, but this wasn't the only barrier. Because the commonwealth was and remains very different from the other RGGI states in terms of its energy profile, the costs and benefits of joining RGGI were different for Pennsylvania and not well understood.

The existence of a Clean Power Plan requirement for every state serves to level the playing field a little bit between Pennsylvania and the RGGI states, but not much. The commonwealth's policymakers should be looking to join with other states in regional compliance strategies to lower compliance costs and maximize economic efficiencies. However, the search for partners is more likely to be found with similar energy-rich states and/or with other states that share the same regional electricity grid.

In the end, the message from Pennsylvania to RGGI is probably more like "It's not you, it's me ..."

Christina Simeone is the deputy director of the Kleinman Center for Energy Policy at the University of Pennsylvania.