Nov. 1--When the state Legislature passed the Green Communities Act last year to boost municipal participation in renewable energy, one of the key provisions was net metering.

To municipal wind power advocates, net metering is the Holy Grail. Before the Green Communities Act, most of the electricity produced had to be used on the same site where it was generated. Also, only a small portion of the excess power could be sold back to the utility, at a relatively low value determined by the volatile daily market price.

Net metering provisions virtually double what municipalities are currently paid for the power they generate through renewable energy. It also allowed the towns to get credits at the wholesale rate for their power, and to list other town departments, or even private homes, as recipients of those credits to pay for their electricity. Municipal wind turbines no longer had to be located next to a big consumer, like a wastewater treatment plant, and could also be larger and capable of producing far more than the town's actual needs, potentially generating much-needed income.

But some Cape municipal and county officials are worried that wind turbines that are still in the planning stages will not get the benefits of net metering because of a cap the state Legislature imposed on the total amount of power that could be generated under the program.

Under the Green Communities Act, utilities can stop participating in the net metering program once they have reached their cap, which is defined as one percent of their historic maximum capacity. In NStar's case that ceiling is a little under 50 megawatts of renewable energy from solar and wind projects. NStar already has 26 megawatts of power from renewables either on line, or in the pipeline, said spokesman Michael Durand.

But with only 9.1 megawatts of wind energy actually online statewide, and many other projects still in the planning phase, state energy officials insist there is plenty of room for new renewable energy projects before that cap is reached. They predict there will be 30 megawatts of wind power statewide by the end of next year, out of a total state cap of more than 140 megawatts.

"Towns should continue to pursue clean energy options without any reason to be discouraged whatsoever," Executive Office of Energy and Environmental Affairs Secretary Ian Bowles said in an e-mail Oct. 23.