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Solar panel waste will not be a problem because there is so little of it. However, there is a short-term problem in some places because panel deployment is growing rapidly and recycling is catching up.
The fastest energy shift in history is underway. New solar PV generation capacity is being deployed faster than everything else combined. The price of PV continues to fall and PV is essentially unrestricted . Therefore, solar PV is growing to dominate not only electricity production, but also all forms of energy production, through the electrification of almost everything.
How much waste?
Typical electricity consumption in advanced economies is 7 to 12 MWh per person per year. This figure will have to double to accommodate the electrification of transport, heating and industry. In some countries, additional electricity will be needed to decarbonize the chemical industry: metals, ammonia, plastics, synthetic jet fuel, etc. Most of this electricity will come from solar energy, with limited support from wind and hydropower.
For illustrative purposes, we can take an average per capita solar electricity generation of 20 MWh per year in a fully decarbonized prosperous country. Assuming a typical DC capacity factor of 16% (roof and ground mounting), each person needs 15 kW of solar panels with a surface area of ??about 70 m2.
The useful life of the panels is 20 to 30 years, so about 3 m2 of solar panel waste is generated per person per year, with a mass of about 30 kg. This is small compared to the US municipal solid waste stream of approximately 900 kg per person per year, and very small compared to the equivalent US CO2 emissions of 19,000 kg per person per year. year .
How much of the photovoltaic modules is recycled?
The aluminum frame and electrical cables of removed solar panels are typically recovered for their value.
Most of the rest of the panel is glass, which is non-toxic and whose raw material is inexhaustible. The mass of glass in 3 m2 of solar panel is about 20 kg. This compares to the current US glass waste flow of 30 kg per person per year. Therefore, if discarded entirely as landfill, solar panels would increase the glass waste stream by two-thirds, which is significant but far from overwhelming. The high quality of waste low-iron solar glass can find specialized applications , including as a starting material for new generations of solar panels and in the traffic sign painting industry.
Solar panels also contain about 1.2 kg of silicon, which is a non-toxic and extremely abundant material (No. 2 in the Earths crust). The rest of the panel is made up of thin layers of protective plastic and a small mass of conductive metals such as copper (Cu), aluminum (Al) and silver (Ag) that can be recovered and recycled, depending on sufficient volumes to justify investments in recycling. of the team.
A growing market in developing countries is the reuse , or second life , of solar panels. Many large-scale solar power plants are replacing their 15% efficient panels with 22% efficient bifacial double glass panels. The same trucks that deliver new panels pick up retired panels, which are then sorted and shipped for a second life in low-power applications elsewhere.
During the initial growth of an industry, the logistics for dealing with products that are initially recalled may not keep up. Currently, this applies to both lithium batteries and solar panels. However, the pace of adoption of both technologies means this will change rapidly. The mature lead-acid battery industry is a good example of high collection rates.
As the photovoltaic industry grows and matures, companies will be developed to sustainably manage end-of-life solar panels. The amount of PV materials to be recycled will remain comfortably below existing waste and recycling streams and therefore no special disposal and recycling technology or logistics is required. The management of the retirement of solar panels will not be a limitation for the replacement of fossil fuels with solar energy.
How much CO2 avoided?
It is important to highlight that the 3 m2 of solar panels per person that are recycled each year have generated 20 MWh of electricity throughout their useful life and have displaced 20 tons of CO2 emissions. This is approximately a thousand times greater than panel waste, and avoiding it is a dramatic environmental gain.
The waste flow from a wind turbine is similarly small compared to the CO2 displaced during its useful life. The images of removed turbine blades and buried solar panels that periodically circulate on the web in shocking articles do not point out the thousand times greater mass of CO2 emissions that the turbines and panels have prevented. |
