Large, flat roofs and open fields lend themselves to solar power. But a bird’s-eye view of most city buildings finds smaller, busy rooftops supporting HVAC units, vents, generators and skylights. That means limited geography for solar panels. One growing sector in solar installation aims to solve the problem—the rooftop canopy that can be mounted overhead without affecting the equipment on a typical roof. 

Young Electric Co. Inc. and IBEW Local 6 installed a 145.6-kilowatt (kW) solar canopy above Young Electric’s downtown San Francisco building two years ago. The electrical contractor and building owner anticipate a return on the investment within a few more years, based on elimination of their power bill.

The solar structure started as a concept several years ago when Young Electric began planning a new roof for its four-decades-old building. The company wanted to try deploying a solar-power system in that space, but like many commercial buildings in populous cities, it would have to work around HVAC units and skylights. The roof would also need to remain accessible to emergency responders. 

If solar panels were laid directly on the roof, accommodating the HVAC units, skylights and safety pathways for first responders would limit the number of panels. Ultimately, the power generation would be too limited to meet the building’s needs.

The solution was to “raise the roof,” said Wayne Huie, president and CEO of Young Electric. “This canopy structure was just, by far, the most efficient way of going about it.”

Once installed in December 2023, it was the first such industrial solar canopy in San Francisco. It includes a photovoltaic array supported by lightweight steel columns, and it offers an 8-foot clearance to allow access to the rooftop for emergency personnel and maintenance workers. 

“The free-flowing, open plan will allow first responders space to safely maneuver on the roof,” Huie said.

Working without protocols or standards

There were no protocols or specifications for a structure like it in the city. So Young Electric worked with San Francisco Electrical Construction Industry (SFECI), the San Francisco Electrical Contractors Association’s labor-management cooperation committee with IBEW Local 6. This collaboration helped ensure the unique system met the city’s permitting requirements, explained Alex Lantsberg, research and advocacy director for SFECI. 

Locally, SFECI’s role was to help guide the project through the local permitting process. There weren’t many models to imitate, Lantsberg pointed out, but there were plenty of challenges. “San Francisco’s commercial and residential district is tight, so we had to get creative about how we did this,” he said.

In San Francisco, “we have a very small geography [jurisdiction], so we have a receptive regulatory apparatus and structure for these demonstration projects,” he said.

The company went to Day & Night Solar, Collinsville, Ill., a solar engineering firm that specializes in such canopy-based solar systems. Their services include special engineering to accommodate the footprint and meet environmental demands.

“Solar power has been through many different stages in the last 16 years” since Day & Night Solar opened its doors, said Bob Eaton, the company’s managing member, president and CEO. He pointed out the large number of buildings with rooftop space challenges.

“With these older, mid- or small-sized buildings, none of the roofs were laid out with any inclination of putting solar on them,” Eaton said, adding that, “spacing doesn’t work—you’ve got shades and shadows, and it really doesn’t lend itself to the traditional roof-type systems.”

It’s a widespread problem for solar across most cities. On average, about one-third of buildings in the United States fall in this category, he estimated. “They’re not solar-friendly because they have too much on their roof.”

270 panels, 8 feet above

The Young Electric building is a wooden post-and-beam construction with vertical posts and horizontal beams, similar to thousands of multistory buildings around the country.

Day & Night Solar engineered the canopy to consist of an array of 270 panels, supported by about 74 columns above the 22,000-square-foot roof. Light-gauge steel transfers loads to the posts and columns to reduce pressure on the building’s structure.

“We basically just took the existing wood structure and went up one more story,” Eaton said.

Because of the height of the canopy, even the skylights remain functional. Huie said he considered eliminating the skylights with the new roof and canopy, but tenants wanted them to remain. They upgraded the skylights and are still getting daylight from overhead. 

“It’s been no impact with the solar canopy,” Huie said.

Educating local emergency response management

To satisfy San Francisco’s local fire district, the companies needed a way to demonstrate how the system works and the lack of negative impact on emergency response. 

As part of the design and engineering, the first challenge was to understand the fire codes where a building is located, and then share the planning with the local jurisdictions. 

“They don’t know what they don’t know, and there’s really no code to follow” for such structures, Eaton said. 

Part of that outreach and education process went digital so permitting agencies could explore a virtual version of the rooftop and canopy from their own offices. 

“We actually took snippets of the live video presentation for them to use,” Eaton said, and enabled virtual 3D walkarounds on the simulated roof and canopy. 

Users could drop a 6- or 7-foot firefighter, with a fire hat or helmet, on the roof and walk the individual around under the canopy. 

“They had clearances to walk around, move around. There was no hindrance,” Eaton said.

That 3D map is something that could be used for other buildings going forward, Eaton added. “That template and model could work on any building.”

Protecting the roof 

Solar canopies also serve a purpose when it comes to protecting the gear installed on the roof below them. They keep rain and direct sun off the HVAC equipment, for example, keeping the units drier and cooler and ultimately extending their lives.

Those in the building benefit, as well, Huie said, adding that it isn’t something they considered when planning. The solar canopy helps shade the roof and cool the building’s temperature on warm, sunny days.

“So you extend the life of the roof, protect their equipment and get the free power while taking tax credits [when available],” Eaton said.

The cost is typically 15%–20% more than standard solar array installations, and the return on investment averages between eight months up to about four years, he said.

In different parts of the country, the arrays must be custom-designed for the environment. Raising the solar units on canopies in some areas can get them out of the shadow of neighboring buildings. Environmental hazards vary, as well. Constructing flexibility in the support joints for canopies in places such as California mean they can be seismically robust. 

In other areas, such as the Plains states, hazards, such as hail, are additional concerns, while some Florida canopies have been built to sustain hurricane-force winds.

The solar canopy  trend is on the rise. In fact, industry statistics from the Department of Energy find that this construction—whether the panels are in a parking lot or on a building—is growing. A People’s Action for Clean Energy 2024 update found that solar canopies help address environmental concerns, reduce urban heat and preserve farmland and forests.

That has proven to be the case for Young Electric. 

“It’s all the power we need,” Huie said, adding that it eliminates an average $4,000 monthly utility bill. So far, he added, it has required minimal maintenance.

Companies such as Day & Night Solar are also benefiting from the trend. In 2025, the company expects to install 400–600 acres worth of solar canopies.

Rooftop canopy for housing

Similar canopies are in the works for residential sites in San Francisco. A local community land trust is preparing to install a system for its 19th-century building with six apartment units, Lantsberg said.

In this case, the system could enable another source of power for a building that was wired during a time of less energy consumption. Older buildings are currently not designed for efficiency either. 

“One of the biggest challenges is that, in many cities, you have all these older buildings that have outdated—or certainly not modern—electrical systems and that are running up against these challenges of decarbonization,” Lantsberg said.

With this next project, he said, “we’re hoping that we can provide this creative solution that’ll allow them to add electrical capacity to the building without having to deal with all the things that come with adding service.”

Ultimately, Lantsberg predicts more solar canopies will be constructed in other cities. In states with clean energy mandates, the canopy can save energy costs, with support from local governments.

ABCDStock / stock.adobe.com | Alex Lantsberg | day & night solar