Land usage is not much of an actual problem. For one sunlight falls pretty much everywhere. You don't need to put a solar plant out away from cities like coal a

Land usage is not much of an actual problem. For one sunlight falls pretty much everywhere. You don't need to put a solar plant out away from cities like coal and oil plants. You can cover the acreage of a city with solar panels. Just putting panels up over parking lots in suburbs/exurbs contributes significantly to the area's power needs. Offshore wind is also extremely productive and eats up no arable/useful land. Farmland is also great siting for wind because there's enough uninhabited acreage to safely put up large turbines. A lot of wind power in Texas for instance comes from turbines on farms and ranches. That's in addition to more site limited renewables like hydro, tidal, and geothermal. There's lots and lots of untapped energy hitting the Earth every day. The Earth is also really big. To handle a few integer multiples of human power needs with renewables by tapping a tiny fraction of that is not outside the realm of possibility or even all that difficult. It's more a question of will than technical capability.