page_title: Cadmium telluride photovoltaics
section_title: Environmental impact
hierarchical_section_title: Cadmium telluride photovoltaics / Environmental impact
caption_attribution_description: English: CdTe photovoltaic panels photographed on an angle extending to center frame. A wind turbine stands in the distance.
context_page_description: Cadmium telluride photovoltaics describes a photovoltaic technology that is based on the use of cadmium telluride in a thin semiconductor layer designed to absorb and convert sunlight into electricity. Cadmium telluride PV is the only thin film technology with lower costs than conventional solar cells made of crystalline silicon in multi-kilowatt systems.
  On a lifecycle basis, CdTe PV has the smallest carbon footprint, lowest water use and shortest energy payback time of any current photo voltaic technology. CdTe's energy payback time of less than a year allows for faster carbon reductions without short-term energy deficits.
  The toxicity of cadmium is an environmental concern mitigated by the recycling of CdTe modules at the end of their life time. Though there are still uncertainties regarding the recycling of CdTe modules and the public opinion is skeptical towards this technology. The usage of rare materials may also become a limiting factor to the industrial scalability of CdTe technology in the mid-term future.
context_section_description: Photovoltaics can assist in reducing toxic emissions and pollution caused by fossil fuels. Emissions from fossil fuels that impact global climates such as Nitrogen Oxide (NOₓ), Carbon Dioxide (CO₂) and Sulfur Dioxide (SO₂) are not emitted from PV. A single gigawatt-hour of electricity produced from PV would decrease the emissions of SO₂ by 10 tons, NOₓ by 4 tons and CO₂ by 1000 tons when compared to coal.
  CdTe cells are considered to be both toxic and carcinogenic when inhaled or ingested as Cd is a toxic compound by the US Occupational Safety and Health Administration. Workers in processing facilities may be exposed to, and inhale, fine particles or fumes of Cd.
  CdTe production facilities may cause environmental issues when there are accidents in high-efficiency production or from by-product exhaust in less efficient production methods.
  During a module’s lifespan, it will not release any particles or vapors if used as intended. The only way for a completed module to release dust or vapor is by being lit aflame or ground into a fine dust. When exposed to temperatures of approximately 1100 °C in lab tests around 0.4% to 0.6% of the Cd content was released.
  The overall Cd air emission estimates can range from 0.02 to 0.5 grams per gigawatt-hour.
  Early CdTe modules failed elution tests, however more recent models can pass some elution tests. Despite the small amounts of Cd that may leach out, CdTe modules have low overall leachability as the hazardous materials within them are encased within two layers of glass. Despite their low leachability, CdTe modules have very poor biodegradability.
caption: a small PV array used as part of Energy Systems Integration research ongoing at the National Wind Technology Center (NWTC)
exif: {"Image ImageDescription": "January 10, 2018 - First Solar, a NREL research partner has installed a small PV array used as part of ESI research ongoing at the NWTC.  (Photo by Dennis Schroeder / NREL)", "Image XResolution": "400", "Image YResolution": "400", "Image ResolutionUnit": "Pixels/Inch", "Image Artist": "Dennis Schroeder", "Image ExifOffset": "78", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "EXIF ExifVersion": "0230", "EXIF ColorSpace": "Uncalibrated"}