Determined that there can be no “green halo” for renewables, solar and wind stakeholders in the United States are tackling the reality that their “green” and “clean” technologies carry their own environmental costs—and that those costs that must be addressed head-on, and not left for someone else to pay.
“Renewables are vaunted for their ability to reduce greenhouse gas emissions as part of the push to address climate change in the United States and elsewhere, but that doesn’t mean they have zero environmental impact,” writes Utility Dive.
Toxic substances generated during the production of some solar photovoltaic (PV) panels, wildlife disruption and land use changes, and recycling and disposal problems are current-day issues that will only deepen and proliferate as renewables scale up.
And scale up they will, adds Utility Dive, citing projections from the Energy Information Administration (EIA) that peg the increase in renewable generation in the U.S. from an 18% share in 2018 to 31% in 2050.
Current PV production methods create far fewer toxins than “vintage” techniques—which, not long ago produced a stew of hazardous byproducts, “including silicon tetrachloride, silane, hydrofluoric acid, and large quantities of acidic and alkaline wastewater needing treatment,” Utility Dive notes. But the industry’s potential to expand means the byproducts it does generate need to be addressed now.
First Solar, which produces 5.7 GW per year in plants located in Ohio, Malaysia, and Vietnam, has replaced the multicrystalline silicon typically used to make solar panels with cadmium telluride (CdTe), which produces an “extremely limited” amount of waste materials.
“CdTe is valuable enough that First Solar situates recycling plants alongside its manufacturing facilities, recovering up to 95% of the semiconductor material, and 90% of the glass, to reuse,” said Andreas Wade, First Solar’s sustainability director.
A further boon: as a waste product from copper mining, CdTe eliminates the need for virgin extraction.
To address land use concerns, organizations like the U.S. National Renewable Energy Laboratory (NREL) are pairing solar panels with agricultural operations like sheep farms and apiaries. NREL’s projects, which alone “will cover three million acres in the U.S. by 2030 and six million by 2050,” have helped “generate public good will for solar developments, especially in rural areas more accustomed to farming,” notes Utility Dive. Meanwhile, Norwegian state producer Statkraft AS is hard at work on “floating solar”—which could limit both forest clearing and wildlife habitat loss.
Statkraft is also pursuing wind turbine technologies that are more bird-friendly than current models. Currently wind turbines kill an estimated 140,000 to 328,000 birds annually—a figure that, while small in comparison to the “hundreds of millions of deaths attributed to colliding with buildings, vehicles, and high-tension lines” each year, can lead to significant localized impacts on certain populations, Utility Dive writes.
For example, StatKraft’s Smøla wind farm—“one of Norway’s largest, with 68 turbines spread over seven square miles”—is sited near a population of 45 to 50 breeding pairs of white-tailed eagles. A decade ago, six of the majestic birds were being killed by turbine blades every year, and the company invested US$4.5 million in everything from “GPS to radar to video monitoring” to try to stop the collisions.
Then, in 2013, StatKraft hit upon a solution: painting one blade black on each turbine. The contrast has been effective: “researchers found a 72% reduction in bird fatalities, and recorded no deaths of white-tailed eagles among the contrast-painted turbines,” Utility Dive writes.
Disposal, however, is still a concern for renewable producers.
“There could be as much as eight million metric tonnes of total solar panel waste by 2030, and 10 times that—nearly 80 million metric tons—by 2050,” reports Utility Dive, citing International Renewable Energy Agency projections.
As parts like wind turbine blades are made of composite materials, they can be nearly impossible recycle. Currently, many blades are shipped to France, where recycling innovator Veolia Environnement grinds them to dust for lime kilns and cement producers. For the longer term, the industry has its hopes pinned on efforts to make blades out of thermoplastic resins, which can be melted down into re-formable liquid resins.
On the solar side, the industry is also accelerating its efforts to stem the tide of renewable waste, with the U.S. Solar Energy Industries Association (SEIA) working “to strengthen the reuse market for PV panels” by partnering with industry exchange network EnergyBin, and by teaming up with recyclers across the U.S.
But more effort is needed on more fronts, said Dustin Mulvaney, an environmental studies professor with San José State University.
“How do we manufacture with fewer chemicals, less lead, less cadmium? I want the standard to ratchet up performance,” he told Utility Dive. “Once everybody gets to 10% recycled glass, raise the standard to 20%, with the goal being a lower carbon footprint for solar panels and lower emissions overall. It’s a big-picture circular economy.”