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Aug 12, 2023

Larger residential solar panels create market for rooftop transport equipment

By Billy Ludt | March 28, 2023 Carrying heavy solar modules up to rooftops is

By Billy Ludt | March 28, 2023

Carrying heavy solar modules up to rooftops is one of the most physically demanding and dangerous parts of an installer's job. That risk is only increasing as PV modules continue to grow in wattage and size.

A panel from Canadian Solar is marketed for residential projects but is about 89 in. long and 44 in. wide — and 71 lbs. Solar installers must determine how best to move these large, thin panes of solar cells wrapped in glass and aluminum framing from a pallet to the roof without hurting themselves or damaging the panels.

Credit: Solmetric

Then, there's the financial risk of citations from OSHA and other bodies monitoring work safety. In California, the state with the largest solar market, installers must be aware of guidelines from the Department of Industrial Relations (DIR).

The DIR mandates that "employees shall be prohibited from carrying equipment or materials which prevent the safe use of ladders," in Section 3276 of "General Industry Safety Orders." It clarifies that safe use of ladders requires a person to always maintain three points of contact with the ladder, meaning either two feet and one hand or two hands and one foot.

In either scenario, is it possible for a single person to safely handle a large-format solar module while on a ladder?

"If you have a process that relies on an installer putting a solar module on their back, that's not a safe process," said Peter Hoberg, product and marketing manager at Solmetric.

As modules get larger, more solutions are emerging to mitigate the risk of carrying hardware up to residential rooftops.

One example is the Module Lift from Solmetric. The company made its name in the solar industry for PV analysis tools that report I-V curves, thermal imaging and panel shading. During the company's time as an in-house engineering firm for national installer Vivint Solar, Solmetric developed Module Lift as an economic solution to hoist solar panels to the roof using a tool found at every install: A ladder.

"If you look at the features that were designed, the patent that was awarded, everything about it is all about safety," Hoberg said. "You could say, ‘Well, if it was really all about safety, you’d have a gold-plated, platinum lift that automatically came out of the truck.’ But the other realistic part is that it needed to be simple, affordable and a couple guys can figure it out."

Module Lift is composed of four components: A rope, ramps, a lift and a pulley. These four components attach to any standard fiberglass ladder to make a manual system for hoisting panels to the roof, one at a time. It's assembled by attaching the pulley to the top of the ladder, placing the ramps at the gap between two sections of the ladder, running the rope through the pulley and attaching the lift to the end of the rope.

The lift uses patented module hooks that attach to a panel's frame and, once attached, an operator at the bottom of the ladder pulls the rope to hoist the panel to another person on the roof.

"It's designed for any solar module with a frame, so it's universal for all frames," Hoberg said. "We haven't come across any modules that are incompatible with it."

As the module travels up the ladder, the ramps prevent it from colliding with the raised section of the ladder. A built-in braking system in the pulley stops the module from traveling backward if someone releases the rope. Module Lift costs about $1,200, and Hoberg said the expense could save installers in the long run, considering potential fines from OSHA and risk of panel damage when transporting modules manually.

Credit: Bailey Cranes

Another solution for bringing modules and other hardware to residential rooftops is TranzVolt from Tie Down, a remote-controlled machine that can carry a range of solar equipment. Tie Down is a metal fabricator that operates in many industries and got its start manufacturing ground screws that prevented trailers from tipping over during hurricanes.

"[TranzVolt] came about because we do a lot of safety stuff," said Michael Maczko, mechanical design engineer at Tie Down. "If you’re handing something up or down on an open-sided building, there's a chance for that person to fall off. We looked at what was there in that market and there really wasn't a great product for it. When you’re putting solar panels on top of the roof, you’re always pulling stuff up. You’re always at the edge of the roof trying to lift something hanging off the side of the building."

TranzVolt G2 is a battery-powered solution that uses a track that resembles a ladder to transport hardware from the ground to above the roof, so installers do not need to lean over the edge of the building. The main Power Carriage unit of TranzVolt automatically locks into the inner channel of the track. When activated by remote, a cable at the top of the track pulls the unit up toward the roof and over the edge of the track. While the Power Carriage weighs about 30 lbs, it can carry up to 250 lbs per trip in about 10 seconds — that's at least three Canadian Solar large-format modules.

Tie Down has developed three attachments for TranzVolt. The first is the Solar Tilt Back Platform, a framed attachment for hoisting solar panels, packs of shingles, plywood and components with similar dimensions that lays down when it reaches the top of the track. The second is the Roofing Platform, an attachment with a flat edge. And the third is the Utility Tray, a 17-by-26-in. bucket or basket. TranzVolt's solution costs around $5,000, depending on the accessories added.

"Being able to have one person at the bottom, one person at the top, we might be able to reduce your crew load and have a smaller crew doing the same amount of work," Maczko said. "Maybe you can increase and have a whole other crew working another job, and hopefully you can increase your daily output as well."

Shifting away from ladder-based and ladder-like hoisting solutions, there is heavy machinery built for the purpose of installing residential solar. Bailey Specialty Cranes and Aerials of Muskego, Wisconsin, manufactures heavy machinery for specialized industries like aviation, window fitting and solar installation.

"Several years ago, OSHA came along and said, here's a new guideline: Anything lifting under 2,000 pounds is not a crane," said Jack Garczynski, sales engineer at Bailey Cranes. "You don't need a crane operator. That's where it just changed the whole industry completely, because crane operators are expensive, and rightfully so, they’re certified and have a lot of different abilities."

Now smaller-scale construction contractors like residential solar installers can rent "mini cranes" without hiring an outside operator and incurring that additional expense. Bailey Cranes developed the Solar 24T Mini Crane, a telehandler with a stand-in basket that can hold solar panels off its side using a rack. The 24T is operated with radio controls located in the basket and it can reach 24 ft vertically and move 16 ft horizontally.

The operator can load solar panels and other hardware onto the rack and lift the components over the roof line to deliver them to installers. The propane-powered 24T has treaded tracks that can be adjusted independently of each other to work with uneven terrains that are common in residential yards. The mini crane is a part of Bailey Cranes’ Brandon line, which can use other attachments like suction cups for lifting glass, a fork for palletized equipment and a winch and hook for hoisting other equipment.

Problem-solvers in the industry are offering new options for solar panel transport that can save installers time and money. Installers should identify their specific needs and invest in the equipment that's right for them.

"It's really about both safety and productivity," Garczynksi said. "How can you do it safely and still be productive? Everybody seems to want to make money, so it's how we can do it safely. That's the biggest push."