How to decommission a solar array, and why it’s important to plan ahead

Decommissioning solar is a current issue that will come to a head in the next couple of decades. Solar systems are long-lasting under the right conditions, yet arrays are regularly put out of commission today. Owner-operators discover manufacturing defects in panels from a company that no longer exists; panel technology is outdated, with energy production that pales in comparison to current modules; or a commercial customer simply needs to replace roof coverings and doesn’t plan to reinstall the array.

For reasons like these, solar arrays are turned off and torn down, and there are few solar companies offering decommissioning services.

“We can’t keep up with the calls, to be honest,” said Cesar Barbosa, president at Verdant Project Management.

Barbosa and his crew at Verdant, a solar removal contractor, remain busy with a workload of primarily removing commercial-scale arrays from rooftops. The same is true for solar EPC HelioPower. In addition to its removal and reinstallation service, HelioPower decommissioned 13 solar projects of varying sizes in the commercial and residential markets in 2018 alone.

“It’s not necessarily that the modules aren’t producing anymore — it’s just that the technology associated with the infrastructure is old and maybe hasn’t lasted and held up quite as well,” said Mike Murray, program director at HelioPower. “People want to expand, and it just doesn’t make sense to build new technology around an old system when you can get so much more energy in such a smaller footprint for lower cost.”

Powering down and packing up

Physically tearing down a solar array is essentially doing an installation in reverse. In practice, it’s not very complicated, but there are important initial considerations, like where the components will end up upon completion.

Before turning off an array for the last time, Verdant lines up potential buyers who will receive the thousands of used panels, inverters and ballasts that might be of value. HelioPower recycles as much of an array as possible.

“I didn’t get into the solar industry to have solar panels taken away to the landfill,” Barbosa said.

Metal components are scrapped, and the panels are often sold to do-it-yourselfers, rural farmers or customers in countries like Kenya and the Dominican Republic who attach the used panels to battery-units and power water pumps and homes.

Teardown time varies by project size. For the larger commercial-scale rooftop removals, it takes Verdant about three to four weeks. It’s the same setup as a construction site: The array is fenced off, lavatories and safety equipment are set up and containers are left to fill with scrap. Skid steers are used to feasibly move a large amount of remaining scrap on the ground.

The first step in teardown is locking out the array from producing any more energy and making sure it’s no longer feeding into the grid. On commercial rooftop systems, wind deflectors are removed first, then mounts, wiring and any other metal component that isn’t going to a buyer is scrapped. Due to the value of the metals (copper and stainless steel), scrap is usually hauled away daily.

A telehandler forklift helps to safely transport pieces of the array from a rooftop worksite to the ground. Panels are stacked and palletized at about 20-per-pallet. Next, wiring and metal conduits are removed. Inverters can be taken apart and internal components are sold as spare parts with the metal container scrapped.

These steps are repeated until the array is cleared, and then the site is cleaned. Structural holes where the array was mounted are filled, landscaping where wiring was entrenched is repaired and repainting takes place where it’s needed.

“Now you have to demobilize and leave that [site] as if it never had solar,” Barbosa said. “It’s really not that complicated.”

Repowering systems

Solar efficiency has grown, and in turn panel costs have decreased. When an array that was installed in the early 2000s needs to be removed for commercial roof cover replacement, the owner should weigh the cost of removal and reinstallation compared to decommissioning and building a new system, especially on larger projects.

“The amount of money you’re going to spend to get this system back up and running is going to make it almost financially impractical compared to decommissioning this entire system and going with something with current technology,” Murray said.

Putting a new solar array in place of a decommissioned one isn’t always a streamlined process. If an owner plans to replace a system, negotiations can carry on for a year or two. But system components can be viable and potentially support a new array without purchasing a new one from the ground up.

“We have this skeletal system,” Barbosa said. “We can find a way to reuse most of that and just replace some components. I think the key will be to figure out how to do it to comply with the 80/20 rule.”

The IRS updated the Investment Tax Credit for retrofitting an energy installation, requiring that no more than 20% of it can be used components. If an array is updated and repowered with these qualifications, it’s eligible for the ITC.

“I think repowering and retrofitting is a tremendous opportunity,” Barbosa said. “The metrics just have to line up.”

Planning for decommissioning

Decommissioning large-scale solar projects can be a preliminary consideration for solar developers and municipalities. The approximately 30-year lifespan of an array seems far away initially, but when the time comes to tear it down, the process isn’t cheap.

States like Virginia and New York have taken proactive approaches to decommission solar at a local level. The New York State Energy Research & Development Authority (NYSERDA) works with New York counties by providing template ordinances for municipalities to work from when considering solar installations.

Cities and solar developers can settle on these terms, but companies should be aware that decommissioning considerations contribute a great deal to total project costs if included.

“It’s really typical in the Northeast United States that local government requires system owners or project developers to have a plan in place to remove solar projects at the end of their lifecycles,” said Houtan Moaveni, senior advisor for strategy and clean energy siting at NYSERDA.

Since ground-mounted solar arrays take up acres of land, especially utility-scale projects, municipalities fear these projects being abandoned and negatively affecting the land they reside on. NYSERDA published the “New York Solar Guidebook for Local Governments,” which contains a six-page chapter on decommissioning solar projects in the state. It includes rules for enforcing seizure if an array is abandoned and gives cost estimates for removing it.

“I think it’s important that we, as an industry — whether it be decommissioning or anything — provide the stakeholders like counties and landowners good information about this stuff and educate people well,” said Francis Hodsoll, CEO of Virginia solar developer SolUnesco. “Take time to educate people about these issues because then we will end up with a better result for our projects if people are imposing conditions based on good information versus unfounded fear.”

SolUnesco authored an ongoing decommissioning resource for Virginia municipalities and solar developers to consult in reaction to growing solar interest in the state. Most counties in the state have already established decommissioning rules.

“Several counties got flooded with solar interest, and it made them skittish,” Hodsoll said. “They started pushing back with more stringent requirements in an effort to control what they perceived as possibly an influx of solar. It’s just a reaction to the nature of this industry, which everybody is out there trying to figure out if they can find a piece of land. It causes a lot of noise.”

And in many cases, Hodsoll said, the projects don’t come to fruition anyway.

Decommissioning a solar array is inevitable, and system owners and operators should be aware of what options they have when the time for teardown comes.