"traditional" estimates are 4-6 acres per megawatt - seriously more than the assumption - which apparently was generated by folks insisting solar will become technically much more efficient and all the old solar panels will instantly be replaced by the latest more efficient conversion panels . . . .
the 4 million mega-watt/hrs needed is a good number, except . . . . of course, that is "current usage" and does not include charging all cars/truck/semis plus heat pumps to replace . . . and electric water heaters to replace . . . and electric stoves to replace . . .
those "replacements" will increase "usage" by tenfold - per current estimating / methodology.
battery storage does not impact the land area required - actually increases it. ALL the energy need has to be generated during solar hours - whether it is used immediately or stored for later use. and the battery banks and switch gear require land area as well. relying on battery storage increases the generating capacity and the battery storage to cover "having a bad cloud day"
bottom line: 17,500 square miles is not an outrageous over or under estimate _for current usage_
but "current usage" don't feed the greenie dog....
multiple by 10.... that's some serious area needed....
wind farms are having their own debacles.... aside from the energy input to manufacture one, they are failing at a much much higher than predicted rate and essentially at an unsustainable failure rate. there has been no required 'failure rate tracking' - so it's based on news reports and company reporting. altho there is a mandatory failure reporting in the works /?/ approved - which should allow much more accurate analysis of how wind turbines are performing. at present, wind power is having real serious problems living up to the free energy bit. to wit, the Danish company who recently withdrew from a contact to build a mega-offshore wind farm when they were required to warranty the long term economic results. (government interference also had really big smidges to do with it . . . )
as mentioned by multiple posters - way far too much "information" is published by people/organizations/industries who generate "truth" / propaganda based on being seriously invested in their technology.