How much photovoltaic glass is needed for 1G watt

“A fully double glass-based PV production will require amounts of float-glass exceeding today's overall annual glass production of 84 Mt as early as 2034 for Scenario 2 and in 2074 for Scenario 1,” they said. “In 2100, glass consumption would reach 122 Mt to 215 Mt.”

Depending on the two scenarios, the German group predicts that demand for solar glass could be met by an annual output of between 1,000 km2 and 1,300 km2 in 2020 and between 12,000 km2 and 22,000 km2 by 2100. The scientists assumed solar module efficiency at a learning rate of 6.7%, starting from a module efficiency of 20% in 2020.

Emerging technologies such as perovskite solar cells and other cell technologies with efficiencies above 25%, if made commercially mature by the industry, might help to considerably reduce the amount of solar glass needed for the current century.

“Looking at the total area of the active PV capacity, the values increase from 4,200 to 4,600 km2 in 2020 to 252,000 to 466,000 km2 by 2100,” the group said. “To put this in perspective, the values for 2100 correspond roughly to the land area of the U.K. or Sweden, respectively.”

The scientists outlined two different scenarios: a conservative one predicting that the world's cumulative PV capacity will reach 20 TW by 2050 and 80 TW by 2100, and a more optimistic scenario envisaging that global PV capacity will reach 80 TW by 2050 and 170 TW by 2101.