The Cooperative announced the completion Tuesday.
The second initiative totaled almost 12 megawatts of renewable energy in 17 projects.
Round II projects were installed in six towns and two districts and are now awaiting interconnection by NSTAR.
So far, four of the 17 projects completed have been interconnected by NSTAR and the remaining 13 solar systems will be connected to the utility by mid-October.
The total photovoltaic energy installed by CVEC since 2010 comes to over 28 megawatts, after the completion of Round II, which is enough to offset almost 89 percent of participants’ electric usage.
Electrical expenses of host municipalities, fire districts and school districts is planned to be reduced by 60 percent.
Round I was completed in July.
Many of the Round I projects can be seen covering the capped landfills of the Cape and Martha’s Vineyard and five of the eight projects of Round I have been interconnected.
New York based firm G&S Solar Installers, LLC led the construction of Round II since early 2014 with Boston based Fischbach & Moore performing the electrical work.
Round I construction was completed by American Capital Energy of Lowell in conjunction with its financing partner, Clean Focus Corporation.