larry fisher, a former New York Times reporter, writes about business, technology and design.
Like that more familiar road, the path to net-zero greenhouse gas emissions is surely paved with good intentions. Increasingly, it’s also lined with the detritus of the renewable energy industries: bits and pieces of wind turbines, solar panels and batteries that have reached the end of their useful lives without a viable recycling strategy. In some respects, the problem follows from good news, not bad. The world needs a whole lot more renewable energy and battery storage if we are to avoid the most hellish consequences of climate change. And (here’s that good news) industrial nations are finally treating the issue with the gravity it demands. In April, President Biden announced that by 2030 the United States will reduce emissions by 50 to 52 percent from the levels of 2005, more than doubling the nation’s commitment under the Paris Agreement. Energy conservation measures — like LED lighting and building insulation — will make a difference. But meeting the Biden commitment primarily means replacing fossil fuels with renewables.
The production implied is daunting — as is the garbage that is sure to accumulate. The New York Times estimates that the number of solar panels and wind turbines dotting the landscape could quadruple. For electric vehicles — now just 2 percent of cars sold — to reach the target market share of 50 percent by 2030, lithium- ion battery production will need to expand exponentially. Moreover, solar and wind can be counted on as reliable renewables only if there is a reliable way to store the energy — and right now, that comes down to massive arrays of lithium-ion batteries. Hence an unpalatable threat: without new technology and policy approaches, many of these products will eventually end up in landfills when they reach the end of their productive lives.
“As a result of our Net-Zero America studies, we’ve had people raising this question more and more,” said Eric Larson, a senior research engineer at the Andlinger Center for Energy and the Environment at Princeton University. “It’s clear we’re going to have to deal with it if we’re to be successful, or even mildly successful, at the transition” to a zerocarbon economy. “You can’t just leave turbine blades strewn around the countryside.”
In addition to wind and solar power, and the electrification of buildings and cars, the Princeton researchers said the 2020s must also be used to continue to develop technologies that, for example, capture carbon at cement plants. But most of the big investment remains focused on clean electricity and storage.
But what about other sources of renewable energy? Many tallies of renewable energy include hydroelectric power, but no new dams are being built in the continental United States; in fact, older ones are being removed for environmental reasons. The case for a new generation of nuclear power plants has been made by some very smart people, including Bill Gates and Stewart Brand, editor of the Whole Earth Catalog. But nuclear may not be politically viable — and in any case, the rollout would be at least a decade away. As for burning biomass for energy, it raises a host of problems from deforestation to local air pollution. So, for now, clean electricity mostly means more solar panels, more wind turbines and more batteries, none of which is easily recycled.
“Photovoltaics, wind and batteries create three separate problems,” noted Julia Attwood, an analyst with BloombergNEF, a provider of strategic research. “The way you would deal with each is slightly different.”
Blowin’ in the Wind
The average life span of a wind turbine is 30 years. The oldest wind farms are now celebrating their 40th birthdays, so there are plenty of obsolete parts to recycle. When I visited Altamont Pass (California’s first wind farm) in 1985, there were already a lot of blades and other bits piling up.
Turbine blades’ “biggest problem is they are gigantic, and there are not many groups that can cut them into pieces that a general recycler can handle,” Attwood explained. “There’s no furnace you can just feed one into because it’s so huge. That’s why they were so often just getting landfilled. The materials in them are not that valuable.”
Turbine blades’ “biggest problem is they are gigantic, and there are not many groups that can cut them into pieces that a general recycler can handle. There’s no furnace you can just feed one into because it’s so huge.”
Most of a wind turbine consists of concrete and steel, which are readily recycled, as are gearbox and generator components. The tricky part is the blades, which can be 200 feet long and weigh 15 tons. Blades are typically made from a composite of glass fiber and epoxy or another thermoset resin. In contrast to thermoplastics such as polypropylene, these cannot be melted down and recycled. So, the blades must be ground up to liberate the fibers, which emerge as a kind of fuzz.
“If you don’t have a nice long continuous fiber, you get more of a balled-up material, which you can put into injection molded parts,” said Karl Englund, a professor of engineering at Washington State University and chief technology officer at Global Fiberglass Solutions. “We’re looking at breaking down these composites into usable forms without liberating the fiber from the resin, utilizing it as a mini-fiber element to reinforce other products.”
Fiberglass scraps can be added to concrete or particle board, but neither is a highmargin business, and Englund said the company has struggled. “People think these guys take high risks, but they don’t,” he said. “They want an instant high rate of return.”
Fiberglass dwarfs carbon fiber in the wind turbine market — Englund estimated it’s 20 times the volume — but that could change as the blades get ever longer. General Electric recently installed a turbine at the mouth of Rotterdam’s harbor with blades 722 feet long. The behemoth will be able to turn out 13 megawatts of power — enough to light up a town with 12,000 homes.
This new generation of monster turbines will increasingly use carbon fiber, a highvalue material with growing global demand. What to do with the carbon fiber after the machines are worn out or obsolete?
Benjamin Rasmussen/Getty Images
According to BloombergNEF, there should be a market for recycled fiber as long as recovering it does not significantly degrade its properties. “We think there are some margins to be made in carbon-fiber recycling,” Attwood said. “If you can sell it for $7 to $8 a kilogram, that’s a good deal because new material is $15.”
Today’s market reflects today’s regulatory environment, which is all over the map. In the U.S., the Resource Conservation and Recovery Act sets basic guidelines at the federal level, but every state has its own moredetailed regulations. The European Waste Framework Directive sets basic policies related to waste management in the E.U., but the European Commission’s Circular Economy Plan seeks to increase the recycling rate of all materials and reduce the amount that can go to landfills.
In Japan, fiberglass-reinforced plastics are regulated under end-product recycling laws, like those for vehicles, home appliances and construction materials, which usually have minimum recycling or reuse targets in the range of 70 to 98 percent. Taiwan and South Korea have similar policies. But in other parts of Asia, composite materials such as fiberglass typically go to landfills or are incinerated to produce electricity.
Under the Sun
Like wind turbines, photovoltaic panels have life spans of 25 to 30 years. And as with wind turbines, the first large-scale solar farms were installed in the early 1980s. But none of those facilities remains in operation. Indeed, most big photovoltaic installations are less than 10 years old, so most of the solar panels that have ever been made are still in the field, still producing electricity.
But as the deployment of solar modules expands, so will the trash. According to the International Renewable Energy Agency, waste modules are projected to total up to 78 million metric tons cumulative by 2050, or 6 million metric tons a year. BloombergNEF puts the number higher; by 2050, the firm expects solar panel waste to increase to 10 million tons annually. That estimate is from September 2020 and will presumably need to be revised still higher in light of the Biden commitment to speed climate change actions.
“We need to look at the whole picture, and more specifically, sustainable photovoltaics,” said Meng Tao, a professor at the School of Electrical, Computer and Energy Engineering at Arizona State University. “Life-cycle management is the major issue of the future. It will make almost all the solar energy we have today unsustainable in one way or another.”
A typical solar panel weighs roughly 45 to 55 pounds and is at least 75 percent glass by weight. The remainder is mostly polymer, aluminum and polysilicon, with a bit of copper, a few grams of silver, and tiny amounts of lead and tin. According to BloombergNEF, without government incentives it does not pay to recycle the panels. Glass and electronics waste recyclers can process the largest part of a photovoltaic module with their existing facilities, although they are not able to recover the precious metals. Most solar panels end up in landfills (except in the E.U. and Japan), because waste recyclers do not want to deal with them, or if there are viable options, they are expensive. Currently, no recyclers take panels without imposing a fee.
“If you take total cost into account, it’s probably $30 to get one module recycled,” Tao said. “We pay Chinese manufacturers $50 to $60 a module for new ones, so recycling is half the cost. If we don’t have a policy, most modules will still go to landfills. We think that we can probably generate $12 per module from the glass and silver. In the end, if we do everything right, we can probably cut recycling cost to $20 a module, capture $12, to still leave a gap of about $8; somebody has to figure out how to get at that.”
Manufacturers are taking responsibility. First Solar, the only major U.S. manufacturer of solar panels, now offers a recycling service agreement to customers, for which they pay an additional fee on top of the module price.
One hopeful sign is that some manufacturers are taking responsibility. First Solar, the only major U.S. manufacturer of solar panels, now offers a recycling service agreement to customers for which they pay an additional fee on top of the module price. First Solar’s thin-film technology uses cadmium and tellurium; 90 percent of that can be reused in new modules. This is not altruism: cadmium is recognized as a hazardous substance by the EPA, so First Solar’s panels are not allowed to go into landfills, and tellurium is one of the rarest materials on earth.
First Solar, moreover, is an outlier. Roughly 90 percent of solar panels sold in the United States are imported from China. China’s troubled Xinjiang region, home to the Uighurs, produces nearly half the world’s polysilicon, a key ingredient in solar panels. When Bloomberg sent reporters to Xinjaing earlier this year, they were not allowed into any factories and did not meet any executives. But as they explained, the area’s dominance stems from its abundant cheap coal and cheap labor from the embattled Uighur population.
Lithium-ion batteries are the dirty secret of electrification and renewable energy. Lithium mining has had a devastating environmental impact on the deserts of northern Chile and Argentina. Cobalt, another key ingredient in the current generation of batteries, is mined in Congo, where child labor and other human rights abuses are rife. The extraction of nickel — yet another ingredient — is predominantly from Australia, Canada, Indonesia, Russia and the Philippines, and comes at an immense environmental and health cost. An electric vehicle employs hundreds and sometimes thousands of lithium-ion cells. An allgreen electricity grid, part of every plan to reach net-zero, will require vastly more to provide energy storage for when the sun doesn’t shine and the wind doesn’t blow.
A lithium mine called Lithium Americas, planned for leased federal land in Nevada, is being pitched as a green project that will free the U.S. from dependence on foreign countries for this critical metal. But catch this irony: Lithium Americas’ largest shareholder is the Chinese company Ganfeng Lithium. The mine has drawn protests from members of a Native American tribe, ranchers and environmental groups because it is expected to use billions of gallons of groundwater, potentially contaminating some of it for 300 years, while leaving behind a giant mound of waste.
As with wind turbines and solar panels, a profitable recycling process has been lacking for lithium-ion batteries. That’s one reason we all have drawers and closets full of obsolete smartphones and laptop computers. Although some batteries can be reused and repurposed in lower intensity applications, there is already a vast number sitting in warehouses, awaiting a viable recycling strategy.
But even as the sheer scale and projected growth of battery production has exacerbated environmental problems, the industry’s growing pains are prompting renewed attention to recycling. Meanwhile, rising costs for raw materials may provide a business case for managing the mess.
Christinne Muschi/Bloomberg via Getty Images
Recycling batteries “is known as a giant problem because lithium-ion materials are quite poisonous to the environment,” said Daniel Liu, an analyst with Wood Mackenzie, a global consultancy firm. But he is hopeful. “Given the current trends in lithium commodities, I suspect by the time we see wholesale decommissioning, that issue will have been solved, because there is value there.”
According to the Union of Concerned Scientists, fewer than a dozen facilities around the world recycle electric vehicle batteries today, with a combined material processing capacity of less than 100,000 metric tons annually. This corresponds to the batteries in 300,000 electric vehicles per year, or roughly 10 percent of global annual EV sales today — and, based on BloombergNEF’s estimates, a trivial 1 percent of expected annual sales in the early 2030s, Lithium recycling facilities are especially limited in both number and processing capacity in the United States, where every major carmaker is determined to ramp up EV production.
There are two dominant methods for breaking down lithium-ion batteries for recycling. Pyrometallurgy involves burning them to remove unwanted organic materials and plastics, leaving the copper from current collectors and nickel or cobalt from the cathode. One common approach, smelting, uses a furnace powered with fossil fuels, and it loses a lot of aluminum and lithium in the process. Most lithium-ion batteries that are recycled in the U.S. are smelted.
An alternative technology is hydrometallurgy, which uses strong acids to dissolve the metals into a solution. But leaching recyclers must preprocess the used battery cells to remove unwanted plastic casings and drain the charge on the battery, which adds cost and complexity.
The two methods can also be combined. That’s the approach taken by Redwood Materials, where J.B. Straubel, Tesla’s co-founder and former chief technology officer, was a cofounder in 2019. For Redwood, tons of spent batteries loaded with toxic materials aren’t a problem, they’re an opportunity.
The beauty of batteries is you can take them down to raw materials, and they don’t degrade … You really can take them down to their most basic form and put them back in the supply chain.
“The beauty of batteries is you can take them down to raw materials, and they don’t degrade,” said Alexis Georgeson, Redwood’s vice president of communications and government relations. “You really can take them down to their most basic form and put them back in the supply chain. We’re already costeffective today over conventional mining. We’re already able to return value to customers today.”
Redwood’s major competitor is Li-Cycle, a Canadian company that bills itself as the largest lithium-ion recycler in North America. Li- Cycle has a proprietary process that involves no smelting, relying exclusively on leaching to extract the valuable minerals.
“We don’t produce any meaningful amounts of waste,” Tim Johnston, Li-Cycle’s co-founder, told Wired magazine. “We don’t produce any meaningful amount of air emissions, we don’t produce any wastewater, and everything is done at a low temperature. The footprint is very small.”
Recyclers say their businesses are economically viable precisely because lithium, cobalt, copper and nickel are in such high demand that it pays to extract them from used batteries that can no longer be repurposed. The International Energy Association warned in May that rising prices for these materials could delay the transition to clean energy, noting that meeting the terms of the Paris agreement would quadruple demand for these minerals by 2040.
Picking Up the Pieces
Now for some perspective — which in this case offers a glimpse of sunshine. According to the Carbon Tracker Initiative, a London-based think tank, with current technology and just a portion of available locations, the energy captured from solar and wind would be equivalent to more than 100 times current global demand. The technological barriers having been met; the only obstacles will be political.
But to paraphrase an old Yiddish saying, “if my grandmother had wheels, she’d be a Tesla.” Recycling adds one more dimension to the technical and political problems that have dogged the transition to renewable energy for three decades. “Because we use so much energy, any alternative energy technology we deploy has to be deployed at enormous scale,” Professor Tao said, “and that creates a bunch of new problems.”
Solar’s Other Problem
One irony of the solar expansion is that the industry will face shortages of some critical materials long before the Biden 2030 production goal is reached. I had never heard of tellurium, a brittle, silver-colored metal-like element discovered in the 18th century in … wait for it …Transylvania. It’s legacy use is in making steel alloys, but it is now used in some photovoltaic panels. “I published a paper 10 years ago about the limited supply of tellurium,” explains Meng Tao of Arizona State. “There’s only about 50,000 tons on the planet. You need to pick up every bit, and put it all into modules.”
Silver is more abundant than tellurium, but there still isn’t enough of it. In a paper published last year, Tao and colleagues laid out the math. Today each silicon cell requires about 70 milligrams of silver and generates 4.5–5 watts peak of power depending on its dimensions and efficiency. That’s about 3 grams of silver on a square meter of silicon solar cells. The known silver reserve on our planet, according to the U.S. Geological Survey, is 560,000 metric tons. Tao’s calculations suggest that all the known silver reserves on Earth would allow a maximum of 36–40 terawatts peak (TWp) of silicon solar panels before they are depleted. This is far short of the 100 TWp needed by 2050 in order for solar to do its part in the race to net-zero.
Research is underway on replacing the silver in solar panels with copper or aluminum, but these technologies have yet to demonstrate the necessary efficiency. Ideally, researchers would develop a completely new solar cell using only Earth-abundant elements, but there is no guarantee that such a technology is possible.