Brown’s Hybrid Solar Panels a First for R.I.

By ROWAN SHARP/ecoRI News contributor

PROVIDENCE — The largest hybrid solar panel installation in the country will go online by March 5, on the roof of Brown University’s new Katherine Moran Coleman Aquatics Center. The system also is the first of its kind at a university, and the first in Rhode Island, but its creators hope it will herald a new wave of solar hybrid power in the state.

Chris Powell, Brown’s director of sustainable energy and environmental initiatives, said the system is composed of 168 hybrid modules. Each module is actually a pair of panels: a photovoltaic (PV) solar panel atop a patented thermal panel. Under full sun, the system will produce enough energy to light the building and heat the million-gallon swimming pool inside. Traditional energy sources will supplement the system on cloudy days.

Hybrid models produce more energy and work more efficiently than photovoltaic panels alone, according to Powell. PV panels are most efficient when they’re cool, which make sunny days a contradiction — the panels still collect more energy overall, but less efficiently. That’s where the thermal panels come in. Each thermal panel is filled with glycol, a water-based, bio-friendly solution similar to antifreeze. The glycol absorbs heat energy to keep the PV cool. The hot glycol is then routed through a heat exchanger that transfers its thermal energy into the pool. Powell also said the stacked panels let the system maximize energy production from limited roof space.

Mike Intrieri, CEO of SunDrum Solar LLC, which makes the thermal panels, said each hybrid module will produce 958 watts of energy under ideal conditions — 308 watts from the PV panel and a whopping 650 from the thermal panel. Intrieri said he’s visited Brown at least once a week throughout the installation and has been consulting on the project.

Brown University initiated the $800,000 project more than a year ago, and it’s now ahead of schedule, Powell said. Though the project didn’t meet the financial terms required by Brown’s efficiency programs, Powell said it makes sense over the long term. He estimated that the panels would pay for themselves in 15-20 years, and last for at least 25.

The 248-year-old university is in a unique position to make investments like this. “A typical business wouldn’t do what we just did,” Powell said, because few businesses can make decisions on such a large time scale.

However, Powell, who also serves on the Rhode Island Energy Efficiency and Resource Council, said he is researching ways that individual households in the state could use these modules. Powell is looking into state incentives that could offset the initial cost and make the systems accessible to more people. Solar panels are already cheaper than they used to be, because European demand and Chinese production have led to larger-scale manufacture of solar equipment, he said. He still isn’t sure whether these hybrid units will soon become a viable option for many Rhode Islanders. “The question is, does the math work?” he said.

Jonathan Olinto director of operations at Sunlight Solar Energy Inc., the company that designed Brown’s installation, said the math works fine. Sunlight Solar has installed smaller sets of the hybrid modules onto five residences, though none in Rhode Island, Olinto said. The systems, like Brown’s, allow houses to draw energy from the power grid on cloudy days.

The Brown University Department of Engineering ordered three additional hybrid modules for educational purposes. Chris Bull, senior research engineer and senior lecturer in the department, said the extra panels would help students understand the system “and not just read about it in a textbook.” Bull said having the modules in the Department of Engineering is “great because we are trying to build a capacity for researching energy. … This will add another dimension to what we already have.”