SAN ANTONIO — The landscapers at a 45-acre solar farm northeast of downtown do not complain that they are paid only in shrubbery. After about three months, the bleating crew has kept the grounds well maintained.

Since April, the site’s operator, OCI Solar Power, has used about 90 Barbados-cross sheep as a low-cost, low-effort solution to controlling the overgrowth that would otherwise impede the company’s technicians.

The 4.4-megawatt solar farm where the sheep graze is part of a series of 400-megawatt plants that CPS Energy, San Antonio’s municipal utility, plans to add to its portfolio by 2016. On average, a megawatt of solar energy can heat and cool as many as 100 Texas homes on an August day. During average temperatures, it can power many times more. (CPS Energy is a corporate sponsor of The Texas Tribune.)

“The sheep have done a really good job of keeping it nice,” Sara Krueger, an OCI Solar spokeswoman, said as she watched seven of them chomp the pasture between two rows of solar panels. “They seem to be moving naturally around the site.”