Constellation will offer its residential customers the option to install SunrunsolarPV systems in four Eastern states.

The Exelon-owned competitive electric supplier will offer homeowners in Maryland, Massachusetts, New York and New Jersey the option to lease Sunrun systems. Customers can also choose another financing option through Sunrun, although Constellation thinks the lease option will be most attractive.

“We want to put ourselves in the position to be their energy advisor,” said Bruce Stewart, chief marketing officer at Constellation.

Constellation’s largest retail business is in Maryland, where parent company Exelon also owns distribution utility Baltimore Gas & Electric. In the four states where it will partner with Sunrun, Constellation has about 700,000 residential customers, although not all will be candidates for rooftop solar. Constellation’s home service company in Maryland, BGE Home, will also offer Sunrun's products.

The energy retailer chose to offer Sunrun in these four states because they are already active solar markets. Massachusetts and New York are ranked No. 4 and No. 5, respectively, for annual PV installations in 2015, with New Jersey and Maryland coming in 10th and 11th.

Constellation is also active in other retail states, mostly in the Mid-Atlantic and Midwest regions. Stewart said the offering could expand to other states, such as Illinois, Texas or Pennsylvania, as solar becomes more attractive in those regions.

By contrast, much of Sunrun’s business is in the Western U.S. Sunrun was the third-ranked residential solar installer in 2015, according to the GTM Research PV Leaderboard, with more than 200 megawatts deployed last year.

For Constellation, the retailer sees the collaboration as an extension of its more holistic offerings in its retail commercial business. “We have a long history of providing solar solutions to our commercial customers, and we are pleased to work with Sunrun to offer affordable solar solutions to our residential customers,” said Stewart. Constellation has 275 megawatts of distributed commercial solar projects under construction or completed.

There is increasing competition among energy retailers, smart home technology companies and solar installers to form partnerships. SolarCity, for example, has offered Nest thermostats to its customers in California. Ecobee just announced its customers will receive a rebate if they choose a SunPower solar system.

Last year, energy retailer Viridian switched from SolarCity to Sungevity as a solar partner, noting that Sungevity was a better match in regards to corporate culture. Sunrun is also working with Ambit Energy and has a pilot underway with Comcast. Another retailer, Direct Energy, went one step further and acquired Astrum Solar in 2014 for $54 million.

Stewart said Constellation’s decision to partner with Sunrun was largely based on Sunrun’s internal structure, which “facilitated a partnership like ours.” Constellation believes Sunrun has a well-run process for moving quickly, especially once customers make the decision to go solar.

Constellation is just starting with residential solar, but will eventually build out bundled offerings through its retail and home services division that could include other efficiency or clean energy options. “We have a really solid reputation of serving the whole house with technology and home energy services,” said Stewart. “And our customers are increasingly asking us what we can do for them.”