Solar, is considered clean energy and a much welcome alternative to fossil fuels. However, like the Silicon Valley Toxics Coalition (SVTC) pointed out in a 2009 report, the problem comes at the beginning and end of a solar panel’s life. The production process of solar energy has been marred by the use of dangerous chemicals that emit greenhouse gases. The fear now is that the growing solar industry may create a whole new set of environmental concerns that will require generations to confront.
Manufacturing solar energy requires potentially toxic heavy metals that produce greenhouse gases that contribute to global warming. The process also requires the use of large amounts of water and electricity which come from fossil fuel-burning power plants that emit toxic greenhouse gases.
Some countries are already heavily polluted due to their dependence on fossil fuels for electricity. China for example is the world’s biggest photovoltaics manufacturer producing nearly half the world’s cells. Researchers in Illinois at Argonne National Laboratory and Northwestern University found that the carbon footprint of photovoltaic panels made in China is about double that of those manufactured in Europe. If the photovoltaic panels made in China were installed in China, the high carbon intensity of the energy used and that of the energy saved would cancel each other out. However, the manufacturing in China is done for Western market. This means that China’s emissions are not being cancelled out, but those in Europe and U.S are, so China will take longer to counter its own emissions.
The solar production process also creates dangerous waste during production and at the end of life of the solar cells or panels, which if not disposed of properly will inevitably cause pollution. In August 2011, a factory in China’s Zhejiang province owned by Jinko Solar Holding Co. one of the largest photovoltaic companies in the world, spilled hydrofluoric acid, a highly corrosive and poisoning liquid, into the nearby Mujiaqiao River killing hundreds of fish and all animals that got in contact with the contaminated water. The levels of hydrofluoric acid found in the river at the time of measurement were 10times more than the permitted limit.
Climate change researcher Aixue Hu found that solar panels also tend to cause regional cooling when converting sunlight into electricity and increase urban area temperatures when the said electricity transforms into heat. However, while large solar arrays can cause some significant regional changes in climate, globally it will not affect the global climate much. In contrast, if people switched from conventional fossil fuels to solar cells, air pollution would be cut by approximately 90%.
Is anything being done?
Regulations and guidelines for the industry have been established. For example, Solar Energy Industries Association, proposed new industry guidelines in a document called the “Solar Industry Environment & Social Responsibility Commitment,” that urges companies to ask suppliers to report on manufacturing practices and any chemical and greenhouse-gas emissions.
In 2011, China also set standards requiring that companies recycle at least 98.5% of their silicon tetrachloride waste. European recent regulations recommend the reduction and proper disposal of hazardous electronic waste.
To stop reliance on fossil fuel electricity, scientists are researching ways to economically store power from solar cells on a large scale. This will enable a self-sustaining process and could enable solar cell factories to run off solar power. With new technologies, in the future, we may entirely rely on solar itself.
Alternatives for the dangerous chemicals are being researched on by numerous scholars. So far the findings are inefficient but it’s an encouraging path being towed. Researchers are working on developing organic solar cells that generate electricity and finding substitute less dangerous chemicals.
SVTC tracks emissions, chemical toxicity, water use, and recycling of high-tech industries and their environmental impact. It relies on companies’ self-reported data for its scorecard, with a target to increase transparency in the production process of the industry.
SVTC believes that if companies adopt sustainable practices early on, then maybe over the next 10 or 15 years, as the panels begin to come down, they’ll be recycled and there will be zero waste.
Whereas recycling will require less energy, saving money as compared to using raw materials, the reprocessing equipment are very costly. This prompts most companies to just throw away the by-products to save costs.
The entry of profit oriented manufacturers into the market that care less about their environmental impact. These manufacturers stubbornly refuse to provide any environmental or sustainability data on their supply chains or manufacturing operations.
Varying regulations and manufacturing practices similarly make it difficult to get standardized data about the environmental footprint of photovoltaic panels. For example, a study released in May, 2014 by Northwestern University and Argonne National Laboratory found that the carbon footprint of a panel from China is twice that of one from Europe, because China has fewer environmental standards and more coal-fired power plants.
The lack of awareness by ordinary persons that solar panels are not all created equal from an environmental standpoint poses a problem since they can’t demand for accountability without knowledge. Also, not every consumer has access to a free take-back program, and indeed many consumers may not even be aware of the need to dispose of panels responsibly.
It seems generally that solutions exist to all the side effects. However to attain this, the use of dangerous chemicals during the production of solar cells and the disposal of solar waste at the end of its lifetime must be effectively contained. Hopefully when the industry matures, solar companies will adopt stronger sustainability measures. Mulvaney of SVTC said that it already registered a change since it began its scorecard survey with more companies producing sustainability reports. Also CIGS-photovoltaic manufacturers; Avancis and Solar Frontier are already using zinc sulfide, instead of cadmium sulfide.