SAN FRANCISCO—Homeowners on the hunt for sparkling solar panels are lured by ads filled with images of pristine landscapes and bright sunshine, and words about the technology’s benefits for the environment—and the wallet.
What customers may not know is that there’s a dirtier side.
Indeed, solar energy is less polluting energy source than coal or natural gas, but panel makers are still grappling with a hazardous waste problem that’s fueled partly by billions in government incentives, an industry that’s creating millions of solar panels each year and, in the process, millions of pounds of polluted sludge and contaminated water.
To dispose the materials, panel companies have to transport it by truck or rail to waste facilities hundreds and, in some cases, thousands of miles away from their own plants.
The fossil fuels used to transport that waste, experts say, is not typically considered in calculating solar’s carbon footprint, giving scientists and consumers who use the measurement to gauge a product’s impact on global warming the impression that solar is cleaner than it is.
After installing a solar panel, “it would take one to three months of generating electricity to pay off the energy invested in driving those hazardous waste emissions out of state,” said Dustin Mulvaney, a San Jose State University environmental studies professor who conducts carbon footprint analyses of solar, biofuel and natural gas production.
The waste from manufacturing has raised concerns within the industry, which fears that the problem, if left unchecked, could undermine solar’s green image at a time when companies are facing stiff competition from each other and from low-cost panel manufacturers from China and elsewhere.
The increase in solar hazardous waste is directly related to the industry’s fast growth over the past five years—even with solar business moving to China rapidly, the US was a net exporter of solar products by $2 billion in 2010, the last year of data available. The nation was even a net exporter to China.
New companies often send hazardous waste out of their plants because they have not yet invested in on-site treatment equipment, which allows them to recycle some waste.
Nowhere is the waste issue more evident than in California, where landmark regulations approved in the 1970s require industrial plants like solar panel makers to report the amount of hazardous materials they produce, and where they send it. California leads the consumer solar market in the US, which doubled overall both in 2010 and 2011.
Several solar energy experts said they have not calculated the industry’s total waste and were surprised at what the records showed.
Solyndra, the now-defunct solar company that received $535 million in guaranteed federal loans, reported producing about 12.5 million pounds of hazardous waste, much of it carcinogenic cadmium-contaminated water, which was sent to waste facilities from 2007 through mid-2011.
Before the company went bankrupt, leading to increased scrutiny of the solar industry and political fallout for President Barack Obama’s administration, Solyndra said it created 100 megawatts-worth of solar panels, enough to power 100,000 homes.
The records also show several other Silicon Valley solar facilities created millions of pounds of toxic waste without selling a single solar panel, while they were developing their technology or fine-tuning their production.
While much of the waste produced is considered toxic, there was no evidence it has harmed human health.
The vast majority of solar companies that generated hazardous waste in California have not been cited for waste-related pollution violations, although three had minor violations on file.
In many cases, a toxic sludge is created when metals and other toxins are removed from water used in the manufacturing process. If a company doesn’t have its own treatment equipment, then it will send contaminated water to be stored at an approved dump.
According to scientists who conduct so-called “life cycle analysis” for solar, the transport of waste is not currently being factored into the carbon footprint score, which measures the amount of greenhouse gases produced when making a product.
Life cycle analysts add up all the global warming pollution that goes into making a certain product _ from the mining needed for components to the exhaust from diesel trucks used to transport waste and materials. Not factoring the hazardous waste transport into solar’s carbon footprint is an obvious oversight, analysts said.
Shipping, for example, 6.2 million pounds of waste by heavy-duty tractor-trailer from Fremont, Calif., in the San Francisco Bay area, to a site 1,800 miles away could add 5% to a particular product’s carbon footprint.
Such scores are important because they provide transparency to government and consumers into just how environmentally sustainable specific products are and lay out a choice between one company’s technology and another’s.
The roughly 20-year life of a solar panel still makes it some of the cleanest energy technology currently available. Producing solar is still significantly cleaner than fossil fuels—energy derived from natural gas and coal-fired power plants creates 10 times more hazardous waste than energy created by a solar panel.
The US solar industry said it is reporting its waste, and sending it to approved storage facilities—thus keeping it out of the nation’s air and water. A coal-fired power plant, in contrast, sends mercury, cadmium and other toxins directly into the air, which pollutes water and land around the facility.
Environmental advocates say the solar industry needs greater transparency, which is getting more complicated as manufacturing moves from the US and Europe to less regulated places such as China and Malaysia.
The Silicon Valley Toxics Coalition, a watchdog group created in 1982 in response to severe environmental problems associated with the valley’s electronics industry, is now trying to keep the solar industry from making similar mistakes through a voluntary waste reporting “scorecard.” So far, only 14 of 114 companies contacted have replied.
Those 14 were larger firms that comprised 51% of the solar market share.