The existing net metering program caps the amount of power that can be sold back to utilities at 4 percent of peak demand for each utility. But all Vermont electric utilities except Green Mountain Power have reached the 4 percent cap.
Darren Springer of the Department of Public Service says that when Shumlin took office in 2011, small projects generated about 12 megawatts. Now there are more than 38 megawatts from installed or pending systems, such as home solar.
Springer said that the details of any expansion proposal aren't firm yet.