A common misconception is that hydroelectricity has the advantage over other renewables of requiring less land. This is not the case. The surface area of Lake Mead is 640 square kilometers -- this much ecologically viable land was destroyed to make way for hydroelectricity. The power generation capacity afforded by the Hoover Dam on this lake is roughly 2 GW.

A solar panel produces roughly (we're lowballing) 100 watts per square meter. Solar panels to produce 2 GW -- the power output of Lake Mead -- would cover about 20 million square meters, or 20 square kilometers. If we assume the solar panels only operate at capacity for a third of a day, that's 60 square kilometers. If we also assume that only half of the used land is actually light-capturing, that's 120 square kilometers.

Even under the most pessimistic of assumptions, solar still uses five times less land than hydro. Realistic solar installations would probably be significantly more efficient than I've assumed. Batteries are also significantly more space-efficient than hydroelectric storage.