Here we compare land use intensity for the life-cycles of photovoltaic power and coal power. Fig. 2 shows the calculations of land transformation and occupation as a function of lifetime of the operation phase. Solar power plants are currently designed for 30+ years of operation. As the lifetime of a solar power plant gets longer, the land transformation per capacity is unchanged, but the land occupation per energy generated decreases. The coal power life-cycle on the other hand requires mining to obtain the fuel. In the United States 70% of produced coal is obtained by strip-mining [35], wherein the land yields a one-time amount of coal per land surface area. Mining for coal can be described as a land transformation per unit of energy generated (km2 TW h−1). Additionally, since the topsoil of mined land takes several decades to restore itself, it can be described as land occupation per unit of energy generated (km2 yr TW h−1). Coal power also requires land for the power plant itself, and land for railways to transport the coal from the mine, both of which should be described with either of the previous two sets of units. Land use for solar power, on the other hand, does not require mining for fuel, and is often described with units of land per rated capacity (e.g., km2 GW−1). However, to compare the two life cycles, both are described herein in units of land occupation or transformation units per energy generated. The land occupation metric captures the most information and allows the best comparison of solar power to coal power.