To limit the worst effects of climate change and stay below 2C, a herculean effort is required to deploy up to 75 TWp of solar energy globally. Towards this end, DNV’s 2023 Energy Transition Outlook North America report forecasts that solar power will overtake all other types of power generation by the mid-2030s and account for almost half of all electricity produced in North America.
Among the many challenges to reach high levels of solar deployment, one challenge is misinformation that delays, obstructs, and sometimes cancels solar projects.
Across the country we are seeing increasing opposition to solar plants being built. A recent USA Today article cited opponents to solar energy claiming “solar panels would drip toxic chemicals from their glass into the ground, contaminating wells. The land under them would heat up and kill all surrounding vegetation. The solar cells and batteries planned to accompany them would be at risk for catastrophic fires that country firefighters would be unable to contain.” And more vaguely, the solar plant would “threaten health and well-being”.
At DNV, we believe it’s time to set the record straight.
THE MYTH: Solar panels are full of toxic materials.
THE REALITY: The only potential human health and environmental concerns in commercially produced solar modules are the trace amounts of lead in the solder used to connect the solar cell inside the module. However, unlike coal ash, solar modules are not considered hazardous waste based on the Environmental Protection Agency (EPA) Toxicity Characteristic Leaching Procedure (TLCP) tests. [1] These tests show that even when broken, the trace amounts of lead in the solder of the solar modules are trapped inside the module and are not leached into the environment. As importantly, many of the elements claimed to be in solar modules are simply not present as shown in Table 1 which lists the materials in typical silicon solar modules.
Table 1 - Estimated amounts of materials in modern dual-glass silicon solar modules
|
Materials |
Percent by weight |
|
Glass |
82% |
|
Aluminum |
7% |
|
Encapsulant & other polymers |
8% |
|
Silicon |
2% |
|
Copper + tin |
1% |
|
Lead |
0.04% (~5 g/m2) |
|
Silver |
0.035% |
|
Arsenic |
0 |
|
Gallium |
0 |
|
Cadmium |
0 |
|
Tellurium |
0 |
|
Selenium |
0 |
|
Germanium |
0 |
|
Chromium |
0 |
|
Indium |
0 |
The misinformation of solar module toxicity misdirects legitimate toxicity concerns away from coal or fossil fuel impacts which do create far more toxic wastes. An appropriate comparison is to normalize the mass of metals in the coal and solar waste streams by the amount electricity produced, i.e., kg/GWh.
Table 2 - Various elements in coal ash and solar module EOL waste (kg/GWh)
|
Elements (kg/GWh) |
Arsenic |
Cadmium |
Lead |
Selenium |
Chromium |
|
Coal ash |
0.5 |
0.2 |
3.7 |
0.8 |
12.3 |
|
Silicon solar module |
0 |
0 |
0.4 |
0 |
0 |
For many toxic elements, PV modules have no contribution and have almost 10x lower lead than coal ash.
THE MYTH: Expired solar modules will pile up and clog our landfills.
THE REALITY: Some media outlets raised unfounded and sensationalistic alarms about a coming glut of photovoltaic (PV) waste from the solar industry. This misdirects attention from the largest waste producers. As can be seen in the table below, 200 million tons of coal ash are produced globally every 2 months. The same tonnage of solar module waste will take 40 years to accumulate globally. If solar modules are simply put in municipal landfills, the modules would represent less than 2% of all the landfill waste. Presently, solar module recycling is growing and is expected to increase as the volumes of expired modules increases over the next 40 years.
Table 3 - Time-to-reach 200 million tons of global waste
|
Global activity |
Time |
Notes |
|
Municipal waste |
1.2 months |
2.01 billion tons of municipal solid waste annually [2] |
|
Coal ash generation |
2 months |
Assume coal ash is ~1/6 the mass of coal |
|
Plastic waste |
7 months |
Global plastic waste is estimated at 353 million tons in 2019 and plastic production at 460 million tons [3] |
|
Electronic waste |
3.7 years |
Global e-waste in 53.6 million tons [4] |
|
⁞ |
⁞ |
|
|
Solar module waste |
40 years |
Conservatively 40 years |
In fact, the transition to large-scale PV adoption represents an enormous reduction in waste mass and toxicity as compared to fossil fuels.
In the face of the dire climate threat, rapid deployment of renewables to prevent climate temperatures from exceeding 2°C is the most important and pressing issue facing civilization. The solar waste stream, already representing a significant reduction in mass and toxicity compared with coal, is already being managed through reuse and recycling, and it does not pose an environmental risk or catastrophe.
Learn more about this topic in our whitepaper: Contextualizing PV end-of-life waste.
[1] Li, F., Shaw, S., Libby, C., Bicer, B. and TamizhMani, G., 2022, June. PV Module Toxicity Testing Methods and Results: A Literature Review. In 2022 IEEE 49th Photovoltaics Specialists Conference (PVSC) (pp. 0879-0882). IEEE.
[2] https://datatopics.worldbank.org/what-a-waste/trends_in_solid_waste_management.html#:~:text=The%20world%20generates%202.01%20billion,from%200.11%20to%204.54%20kilograms.
[3] https://www.oecd.org/newsroom/global-plastic-waste-set-to-almost-triple-by-2060.htm
[4] https://weee-forum.org/ws_news/international-e-waste-day-2021/
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