At his international climate summit in April, President Joe Biden vowed to cut U.S. greenhouse gas emissions in half by 2030. The goal will require sweeping changes in the power generation, transportation and manufacturing sectors. It will also require a lot of land. Wind farms, solar installations and other forms of clean power tend to take up more space on a per-watt basis than their fossil-fuel-burning brethren. A 200-megawatt wind farm, for instance, might require spreading turbines over 13 square miles (36 square kilometres). A natural-gas power plant with that same generating capacity could fit onto a single city block. Achieving Biden’s goal will require aggressively building more wind and solar farms, in many cases combined with giant batteries. To fulfill his vision of an emission-free grid by 2035, the U.S. needs to increase its carbon-free capacity by at least 150%. Expanding wind and solar by 10% annually until […]