It’s a 19th-century building, but its hot water system is now in the 21st. On Friday, owner Peter Rubins and Assured Solar Energy of North Yarmouth installed three solar panels on the 161-year-old Bates Street brick building. In the early 1980s, a former tenant had installed handmade solar panels on the roof. Those panels ran through their life expectancy and Rubins took them down five years ago when he put on a new roof. But he always wanted to replace them.

“Whether you believe it or not, the glaciers are melting,” he said. “Every little bit helps.”

The new panels cost $10,000 and will run hot water for 28 Bates St., which houses two apartments and Taboo Hair Design. Rubins believes the panels will heat, on average, 60 percent of the tenants’ hot water. It will take five to seven years to recoup the cost of the panels.