Stern professor Bryan Bollinger and his colleague at Yale University, economics professor Kenneth Gillingham, are entering the third round of a project on the diffusion of solar technology.

This fall, Bollinger and Gillingham will be using the $2 million three-year grant from the Department of Energy’s SunShot Initiative to continue their research on how to increase the use of solar energy and solve the problem of high costs.

The two are working with SmartPower, a green marketing firm, and the Connecticut Clean Energy Fund, which started the Solarize CT program last spring. The program attempts to make solar energy accessible for consumers through grassroots marketing and a tiered pricing system. Solarize provides towns with contractors to install solar energy, and the installation prices decrease when the number of residents that adopt solar energy increases.

Part of their plan this fall will be to implement variants of the Solarize program. One is called the Solarize Choice, where they will provide a town with more than one contractor, and the other is called Solarize Express, which will reduce the time of the program from 20 weeks to 10 weeks.

Bollinger said in the first and second rounds, the program has had successes in towns in Connecticut and Massachusetts, but it is not clear what components of the Solarize program are most important.

“Our funding is essentially to fund additional Solarize programs in Connecticut and other towns, where we actually modify the program,” Bollinger said. “This will help us to access what components are crucial in leading to such success.”

Gillingham said the objectives of their project are to determine a cost-effective marketing approach to accelerate the diffusion of solar energy and to figure out why new technologies are adopted.

“The grant allows us to run a set of randomized controlled trials to see what interventions work better than others, while also funding our social network research,” Gillingham said.

Bollinger and Gillingham published a paper last year about the social influences that affect the solarization of a community, and now they want to better understand those influences.

“The whole point of the project is to assess the impact of possible interventions that could be used to help consumers understand the value of installing solar,” Bollinger said.

NYU environmental studies professor Mary Killilea said the cost of solar energy is one of the main challenges associated with its use, and she stated that Bollinger and Gillingham’s research will be beneficial.

“It’s good to see them spending money on this research,” Killilea said. “We need to understand what kind of market and what kind of social structures are going to allow for that diffusion as this technology develops and becomes more affordable as well.”

Bollinger is hopeful that this research will help spread the use of solar energy.

“Solar energy is a fascinating topic, and it’s crucial for energy dependence and a variety of things down the road,” Bollinger said. “Solar has a lot of potential.”

A version of this article appeared in the Tuesday, Oct. 1 print edition. Additional reporting by Davis Saltonstall. Emily Bell and Nicole Brown are news editors. Email them at [email protected].