How much land space is required to meet the energy needs of the United States with solar?

Mathematics Asked by Dev Dhruv on December 7, 2020

The calculations I made below with current data suggest that over half the land of the United States would be needed. Is this indeed an accurate estimate?

The United States used 100.2 Quadrillion British Thermal Units of energy in 2019.

United States Annual Energy Consumption: 29.37 Petawatt-Hours

United States Daily Energy Consumption: 80.40 Terawatt-Hours

Lithium-ion batteries have 95% battery efficiency, 80% depth of discharge, 5% charge controller and inverter losses, 5% temperature losses.

Lithium-ion Battery Capacity: 116.3 Terawatt-Hours

The Tesla Gigafactory takes up 1000 acres of space and outputs 35 Gigawatt-Hours of energy annually.

Daily Gigafactory Output: 95.82 Megawatt-Hours

In order to meet the energy needs of the United States, 1.215 million gigafactories are required to store all the solar energy for use at any time of day.

Space Required for Batteries: 1.898 million square miles (53.57% of US Land)

The amount of energy that can be generated with solar panels depends on the number of peak sun hours in a day, which varies throughout the country. In southwestern states, like Arizona, experience an annual average 5 to 6 sun hours per day.

Power Output of Solar Panels: 23.27 Terawatts (assuming 5 peak sun hours per day)

A 12 panel Tesla solar array can generate 4.08 kilowatts of power and takes up 240 square feet of space.

Space Required for Solar Panels: 49,100 square miles (1.39% of US Land)