Rooftops aren’t the only place to harvest a few kilowatts of solar power for smaller energy applications. Homes with yards or in off-grid locations can use the soil underfoot or south-facing walls to mount some solar panels. Solar mounting manufacturers offer a number of alternatives for homeowners looking for a different kind of installation.
Pole-mounted photovoltaics are commonly found in roadside and smaller off-grid applications, powering devices like traffic lights and water pumps. But those are side-of-pole mounts and produce significantly less energy than a typical array. However, top-of-pole mounts (TPM) can hold many more modules and work well for off-grid solar projects.
With one pole as a foundation, TPM systems adapt well to undulating topographies. When installed in succession in these conditions, the poles can remain level with one another.
“One of the biggest advantages is just being able to put it wherever it needs to be placed,” said Steve Schumacher, national sales manager, Preformed Line Products (PLP). “It’s just a whole lot easier than trying to get a racking system to work on a hillside.”
PLP carries TPM systems in horizontal and vertical module orientations and a multi-pole model with multiple footings. These TPM systems can hold up to 15 modules and max out at about 5 kW for each table with high-production panels.
Additionally, single-post TPMs are adjustable, both in orientation and angle. On PLP’s models, panels can be moved from 15° to 65° in 10° increments. This is possible through a mounting sleeve that is fastened to the top of the pole with an adjustable support bar. Schumacher said people often reorient their TPM systems in the fall and spring, compensating for the sun’s changing path throughout the year.
“You could physically go out there and spin it on the pole,” he said. “They’re trying to get every last ounce of power out of their solar panels.”
Wiring TPMs can be done by drilling a hole at the top of the pole, running the cabling to the bottom and running it out another hole on the pole’s side. PLP uses concrete foundations that vary in length and diameter depending on soil type. They’re tested to withstand snow loads of about 90 psf and wind loads of 150 mph.
“There are limitations, but they’re pretty extreme,” Schumacher said.
Carports, canopies and ground-mounts
Rooftop solar is the predominant choice for residential solar, but Mike Zuritis, president of Solar Foundations USA, said he’s finding more people are choosing ground-mounted projects when considering what is required to mount an array overhead. Penetrations are typically needed for rooftop arrays, so any roof maintenance means the modules will have to be considered.
“When you put it on a ground-mount structure, you can orient the array to optimize the PV production, and the maintenance capabilities are obviously simplified when it’s on the ground itself,” he said. “You potentially have a lot more versatility in terms of what you can additionally use that structure for.”
Solar Foundations USA focuses on producing ground-mount structures for residential and small commercial clients.
Solar Foundations’ structures use ground screws rather than I-beams. On larger projects, some developers will use driven piles requiring pullout tests to determine the foundation’s capacity in a jobsite’s soil, but Solar Foundations has found ground screws work in precarious soil conditions and don’t often require pullout tests, skipping that step altogether and saving money.
The company’s fixed-tilt ground-mounts, canopies, carports and pavilions are custom-designed on a per-project basis with leading-edge heights up to 9 ft and use a rectangular steel substructure across all systems. Like TPMs, system orientation isn’t bound to what direction the roof is facing. Solar Foundations has manufactured fixed-tilt systems with leading-edge height up to 5 ft for use on farms and around livestock. Expansion is a simpler prospect on fixed-tilt systems where roof space doesn’t come into play. As long as there’s more yard, there can be more modules.
Staying on trend with non-traditional solar structures, Smartflower takes a different approach to create renewable energy. Where customers may ask installers to conceal modules as much as possible on rooftops or in yards, Smartflower’s eponymous product is meant to draw attention to itself.
In its fifth iteration, the 2.5-kW PV “sculpture” is also a solar tracker with petal-shaped modules attached to a column. At sunrise, the Smartflower’s modules unfurl, track throughout the day and close at sunset. Mark Conroy, president of Smartflower Solar, said the system is meant to mimic the heliotropic qualities of a sunflower.
“Just as people buy Teslas or Ferraris to basically show off a novel, artful form, that’s the same idea as Smartflower,” he said.
It’s eligible for the same tax credits and rebates as traditional ground-mounted and rooftop solar. All of its components are packaged together and the main structure comes preassembled. Conroy said trained contractors can install the Smartflower in about a day. The foundation and trench for utility interconnect can be dug with a skid steer loader and the Smartflower itself can be placed with a forklift or crane.
The system can use cast-in-place and precast foundations for footing, as well as helical piles or a steel base. When the Smartflower has a steel base, it can be moved around more easily for transient off-grid applications.
If the roof or yard aren’t an option, installers can look to the south-facing walls of buildings to mount a solar array. Racking is available to attach modules vertically and tilted off a wall surface to create an awning.
Some installers have adapted existing mounting hardware to mount modules to walls, but solar structure manufacturer Opsun carries Sunrail WM, a wall mounting system that works on all popular wall types. Modules can be placed flat to the wall or at any desired angle, and in landscape or portrait orientations.
Like the Smartflower, vertical or wall-mounted solar modules can be an aesthetic choice, taking a cut in production for visibility’s sake. However, installing them at an angle will produce more energy than if they’re flat to the wall.
When a client is considering a smaller solar array, the rooftop doesn’t need to be the default. With a big enough yard or unobstructed walls, there’s potential for solar in almost any environment.