REHOBOTH, Mass. — Colorado-based Clean Energy Collective (CEC) recently held a grand opening to show how a community can grow its own solar array.

In a cornfield in this small right-to-farm town, CEC built a 4,400-panel community solar installation, one of 40 such solar projects CEC has built or is building nationwide. Rehoboth’s solar array has been up and running since June.

Community-based solar installations open up access to renewable energy for renters, businesses and nonprofits, according to Ronald Wedeking, CEC’s vice president of business development. Anyone with a National Grid electric bill in the Southeastern Massachusetts Area (SEMA) of the utility grid can own part of the Rehoboth array, without the maintenance and repair hassles.

CEC has set up a trust for operations, maintenance, taxes and insurance funds from panel sales proceeds. In the event that CEC no longer exists, the funds are still there, Wedeking said.

About 20 percent of the 4,400 panels have already been purchased, he said.

How it works
Each owner pays about $1,000 for a panel — a cost of $4 per watt of power for a 250-watt panel. The panel’s percentage of the array’s energy generated monthly is taken off the panel owner’s National Grid bill.

Given an average 1,057 hours of electricity production annually, each panel will produce about $100 a year in energy-bill savings. The panel will pay back the initial investment within eight to 10 years, Wedeking said. If the cost of electricity increases, then the panels are paid off quicker.

“It’s a hedge against electrical energy cost inflation,” he said. “As power costs increase, the solar garden will bring in a 7 to 8 percent return on the panel owners’ investment.”

Other benefits include getting Massachusetts Solar Renewable Energy Certificates (SREC) typically only given to homeowners, making it more attractive to renters and nonprofits. CEC’s ownership arrangement monetizes solar tax credits and builds them into the electrical payments to each panel holder.

The energy payments to panel owners are transferable for moves within the SEMA-National Grid service area. If they move outside of the service area, they can sell their panel(s).

Renewable roots
CEC began five years ago in Colorado, when founder Paul Spencer wanted to create a neighborhood solar farm near the community of El Jebel. Putting together the permits and then the actual electrical power-purchase agreement with the utility meant that Spencer, a software designer, had to write his own program to allocate the solar farm’s energy to the various panel owners’ bills.

The result was RemoteMeter, a software program that tracks each panel’s usage on a solar farm in 15-second intervals and relays that to the utility and to the panel owner. It’s now available as a smartphone app.

CEC currently has arrays in eight states, and is in discussion with 130 utilities.

Other than using state tax credits, the solar gardens don’t receive any government subsidies. CEC uses private funds through a capital stack that is a combination of tax equity partners, debt partners and equity partners, Wedeking said.

Another solar garden will open next month in Hadley to serve Western Massachusetts Electric Company customers who want to go solar. Eight more are planned to be under lease or in place in Massachusetts by the end of this year.

Boston-based Blue Wave Capital, a renewable energy developer, obtained the original permits for the two gardens in 2013 and secured siting; CEC bought both sites from Blue Wave in April. RGS Energy performed the engineering, procurement and construction.