Last November, Japan’s Environment Ministry issued a stark warning: the amount of solar panel waste Japan produces every year will rise from 10,000 to 800,000 tons by 2040, and the nation has no plan for safely disposing of it.

Neither does California, a world leader in deploying solar panels. Only Europe requires solar panel makers to collect and dispose of solar waste at the end of their lives.

All of which raises the question: just how big of a problem is solar waste? //

• Solar panels create 300 times more toxic waste per unit of energy than do nuclear power plants.

• If solar and nuclear produce the same amount of electricity over the next 25 years that nuclear produced in 2016, and the wastes are stacked on football fields, the nuclear waste would reach the height of the Leaning Tower of Pisa (52 meters), while the solar waste would reach the height of two Mt. Everests (16 km).

• In countries like China, India, and Ghana, communities living near e-waste dumps often burn the waste in order to salvage the valuable copper wires for resale. Since this process requires burning off the plastic, the resulting smoke contains toxic fumes that are carcinogenic and teratogenic (birth defect-causing) when inhaled. //

To make these calculations, EP estimated the total number of operational solar panels in 2016 and assumed they would all be retired in 25 years — the average lifespan of a solar panel. EP then estimated the total amount of spent nuclear fuel assemblies that would be generated over a 25 year period. EP then divided both estimates by the quantity of electricity they produced to come up with the waste per unit of energy measure.

While nuclear waste is contained in heavy drums and regularly monitored, solar waste outside of Europe today ends up in the larger global stream of electronic waste.

Solar panels contain toxic metals like lead, which can damage the nervous system, as well as cadmium, a known carcinogen. Both are known to leach out of existing e-waste dumps into drinking water supplies.