Solar carport project at California medical plaza solves tricky energy billing

Watthub Renewables and Sunrock Distributed Generation completed a 322-kW solar photovoltaic system at Irvine Heritage Medical Plaza, the three-story Class A medical office building in Irvine, California. Solar modules were installed to carports covering approximately 108 parking spots, turning bare asphalt into shaded, covered parking and into the building’s primary source of electricity.

The system is expected to generate approximately 515,690 kWh in its first year, covering the majority of the plaza’s annual electricity consumption. It was delivered under a 25-year power purchase agreement requiring no upfront capital from Irvine Heritage’s ownership. Watthub and Sunrock DG financed, engineered and contracted by SunRenu Solar. Sunrock DG now owns and maintains the array, while the property buys the power it produces at a rate below Southern California Edison’s.

Irvine Heritage Medical Plaza was built in 2008 on just over two acres, with approximately 40,000 sq ft of medical suite.

“Medical office is one of the few property types where the parking lot is part of the patient experience,” said Aaron Moston, director at Watthub Renewables. “Somebody’s coming out of a medical or dental procedure at two in the afternoon in August. Whether their car is 140 degrees or 95 degrees is not a small thing. Carports were the right structure here before we ever ran the production model — the fact that they also happen to be the best south-facing real estate on the property is what made the project work.”

Irvine Heritage Medical Plaza is master metered, meaning the entire building draws electricity through a single Southern California Edison (SCE) account on the GS-3-TOU commercial rate, and that cost flows through to tenants inside their charges rather than through individual utility bills. For years, that meant every practice in the building carried a share of an electric bill it could not see or control in a utiliyt territory with rate increases and, during the summer, on-peak energy.

Since solar generation is netted at the master meter, the savings are not captured by one tenant — they reduce the building’s total electricity cost.

“A master meter is usually described as a disadvantage — tenants have no visibility into their usage and the owner absorbs every swing in the energy bill,” said Wilson Chang, CEO at Sunrock DG. “For a solar project it’s the opposite. One meter, one interconnection, one bill to offset and every suite in the building benefits automatically. It’s the simplest way to bring solar to a multi-tenant property.”

Earlier this year, developed another 300-kW solar carport project for the Foothill Medical Association in Foothill, California. The system was also commissioned with a PPA.

News item from Watthub Renewables