Why do solar panels produce dangerous waste

Do solar panels generate 300 times more toxic waste per unit of energy than nuclear power plants?

No. Nuclear energy produces far more toxic waste than solar energy.

Spreading the fake news

The fake news that circulated in late June 2017 came from a self-described "study" conducted by nuclear industry attorney Environmental Progress (EP). Unfortunately, James Hansen, a nuclear proponent who was previously a leader in climate modeling at NASA, spread this disinformation. In February 2018, he said he did not know the method of creating the graph he was displaying. EP only published the graphic on their blog, describing their method: "The study defines the spent fuel from nuclear power plants and the solar panels themselves as toxic waste." They used the TrinaSolar module specifications, assumed a 25 year lifespan, and used the entire installed volume of the module as volume of toxic waste. For nuclear power plants they only used the spent fuel assembly. You came to the two numbers displayed in a bar chart and repeated in various articles and in Hansen's presentation: 34,000 cubic meters per TWh for solar and 101 cubic meters per TWh for nuclear. (Deasi and Nelson 2017).

The blog was immediately embellished by several conservative news outlets, including SlashDot and the National Review. Some articles added to the strange logic. For example, a life cycle cost analysis was performed comparing solar energy to nuclear power, assuming that this solar panel waste would need to be buried in 2 to 5 km deep boreholes that are being considered for spent fuel. (Middleton 2017). Another article in the Daily Caller explained why solar panel waste should be considered more dangerous than nuclear waste: nuclear waste is radioactive and therefore disappears, while the solar panel module does not degrade radioactively after 30 years on your roof and will be disposed of permanently. (Follet 2017).

Toxic waste electricity from solar PV

Most of the mass of a solar panel is made of glass, which can be recycled. The steel case is also recycled. The panel itself is usually made of silicon, which is also non-toxic and can be recycled into new semiconductor material. A fraction of the solar modules use CdTe as a semiconductor material. Lead and silver are caught in the waste stream for all solar modules, but the most problematic waste that is generated in the manufacture and disposal of solar modules is cadmium. Even with CdTe solar modules, nuclear energy generates more cadmium waste per unit of energy. (Mulvaney, 2014) Manufacturers of CdTe panels monitor occupational safety and environmental emissions and have not had any incidents in ten years of US manufacturing. (Heard, 2014)

Even if you only look at cadmium and mistakenly assume that solar panels are being discarded and not recycled, nuclear energy creates more cadmium in waste than solar panels in the entire manufacturing process. Nuclear energy produces a wide variety of toxic wastes, and a minor component is cadmium. Even as a small part of total nuclear waste, it is still significant compared to cadmium produced from other energy sources (Mulvaney, 2014):

  • Coal: 3.0 g Cd per Gwh
  • CdTe PV: 0.3 g Cd per Gwh
  • Si PV: 0.0 g Cd per Gwh (or 0.9 g Cd per Gwh if produced with electricity from coal)
  • Cleavage: 0.5 g Cd per Gwh

Toxic waste stream from nuclear power plants

While nuclear fission produces more cadmium waste compared to CdTe solar modules, cadmium is hardly the only waste from fission. Nuclear waste comprises many categories of radioactive waste with different storage requirements. Spent nuclear fuel makes up a small fraction of all radioactive waste.

Nuclear power waste includes: (IAEA 2018)

  • HLW (High-Level Waste) contains spent fuel and has had to be contained for tens of thousands of years
  • ILW (Intermediate Level Waste) radioactive waste that has been held back for thousands of years
  • LLW (Low-Level Waste) "requires robust insulation and containment for periods of up to a few hundred years" but can be stored in facilities near the surface
  • VLLW (very little waste) can be disposed of in special landfills

CPR is only 0.06% of total radioactive waste, and only 1% of CPR is solid, the fraction of waste that contains spent fuel. Less than 0.0006% of nuclear waste is spent fuel, the only part of the waste on the EP blog. In other words, nuclear energy generates 160,000 times more radioactive waste than spent fuel alone. (IAEA 2018) Per unit of energy, this means that nuclear power plants produce 500 times the amount of waste compared to solar modules, but only if you count the entire solar module and ignore the waste generated when nuclear power plants are decommissioned.

Used nuclear fuel rods must be contained for several thousand years. In breeder reactors such as a thorium reactor, 0.0006% of the nuclear waste stream that is consumed as nuclear fuel is recovered. The plutonium is separated from the spent fuel, which brings with it the additional risk of a nuclear weapon. (Ford and Schuller 1997, p. 111)

References

Desai, J. and Nelson, M. (2017). Are we facing a solar waste crisis? Retrieved from http://environmentalprogress.org/big-news/2017/6/21/are-we-headed-for-a-solar-waste-crisis

Follett, A. (2017). Solar panels produce 300 times more toxic waste than nuclear reactors. Retrieved from http://dailycaller.com/2017/07/01/solar-panels-generate-300-times-more-toxic-waste-than-nuclear-reactors/

Ford, JL and Schuller, CR. (1997). Control of Nuclear Safety Threats: A Holistic Model. Washington DC: National Defense University Press.

Fthenakisa, V. and Kim HC. (2010). Life cycle use of water in power generation in the US. Renewable and Sustainable Energy Reviews, 14 pp. 2039-2048. Retrieved from https://www.sciencedirect.com/science/article/pii/S1364032110000638/pdfft?md5=e76eb25e7a96a5886503e1aaf0d282d7&pid=1-s2.0-S1364032110000638-main.pdf

Heard, A. (2014). Reply to Mulvaney. Retrieved from https://www.sciencedirect.com/science/article/pii/S0016718514001705

IAEA. (2017). Trend in electricity delivered. Retrieved from https://www.iaea.org/PRIS/WorldStatistics/WorldTrendinElectricalProduction.aspx

IAEA. (2018). Status and trends in radioactive waste management of spent fuel elements. Retrieved from https://www-pub.iaea.org/books/iaeabooks/11173/Status-and-Trends-in-Spent-Fuel-and-Radioactive-Waste-Management

Middleton, D. (2017). Waste from solar panels: 300 times as much as nuclear power. Retrieved from https://wattsupwiththat.com/2017/06/29/toxic-waste-from-solar-panels-300-times-that-of-nuclear-power/

Mulvaney, D. (2014). Are green jobs just jobs? Cadmium Tales in the Life Cycle of Photovoltaics. Geoforum 54, pp. 178-186. Retrieved from https://www.sciencedirect.com/science/article/pii/S0016718514000281

World Nuclear Association (2017). Disposal of radioactive waste. Retrieved from http://www.world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-wastes/radioactive-waste-management.aspx

T. Sar

@MichaelK Why do you say that the toxic waste from solar panels lasts forever? Do you have any sources for this?

T. Sar

@MichaelK Cadmium is also a normal waste from nuclear power plants so I don't understand where you are coming from. According to your logic, nuclear power plants also have toxic waste that lasts forever!

T. Sar

@ MichaelK Not exactly. Right now I've shown some evidence that nuclear power plants produce more waste than solar panels (as stated in this answer), but I am open to change my mind if anyone comes up with something that shows this answer is wrong. I'm not sure the personal attack is necessary.

Bennett Brown

Just taking into account the cadmium in the fission products and only the minority of solar modules that use CdTe semiconductors, the fission power generates twice the cadmium per GWh compared to CdTe solar modules.

Bennett Brown

There is no toxic waste from solar panels that needs to be disposed of. it is recycled into the material inputs. The vast majority of nuclear waste must be stored and cannot be recycled, even in a spent fuel reprocessing scenario.