Well, solar would apparently need about 0.6% of the land area of the USA, which is assuming pure photovoltaic power @ 2008 performance levels. Based on the report cited here:
https://solar.gwu.edu/how-much-land-would-it-take-power-us-solarThat's, you know, do-able. The above source cites 1948 sq ft of solar panels per person to power people to USA-levels of consumption, and since the total world population has an average density of about 148 people per sq.mile, it works out at 1% global land-coverage to power everyone on the planet to USA levels of electricity consumption with just 2008-grade solar panels.
Of course, USA is near the top of the charts for being energy-hogs, so basing anything off USA-levels of consumption is a massive over-estimate. World per-capita electricity consumption is 1/4th to 1/5th of USA-levels, so would need a land-usage of ~0.2%
https://en.wikipedia.org/wiki/List_of_countries_by_electricity_consumptionwith some market-driven changes in consumption, along with improved solar panel designs and energy-saving measures, it would be practical to have 100% of baseload power provided just by solar panels, covering maybe 0.1% of total land area, much of which can be rooftops.
A couple other ways to look at this are in this article:
https://landartgenerator.org/blagi/archives/127... this one comes up with a world figure of half-a-million sq km of solar panels to power the world for total energy needs (not just electricity). That's out of 150 million sq km of total world land area, so about 0.33% of total land area, which is pretty much in line with the above estimates. To put this in perspective:
According to the United Nations 170,000 square kilometers of forest is destroyed each year. If we constructed solar farms at the same rate, we would be finished in 3 years.
There are 1.2 million square kilometers of farmland in China. This is 2 1/2 times the area of solar farm required to power the world in 2030.
And here, where it's pointed out that the amount of land destroyed by coal mining means that it has a bigger land-footprint than a solar plant:
https://www.google.com/search?client=firefox-b-d&q=how+big+is+a+coal+planetSo, we have no qualms destroying or otherwise extracting resources from areas of land
far in excess of the amount we'd need to convert to solar, but somehow the only time we have the "there won't be space!" argument is in relation to alternative energy.
Also ... another important point is that you're not going to rip up economically valuable farmland to build your solar plants, you're going to purchase economically marginal land and develop a solar plant there, because that raises the economic value / resource potential of that chunk of land. Solar plants will spring up in otherwise-useless tracts of land that are located nearby to urban centers. Solar is going to be a good thing because it generates a resource out of otherwise useless bits of land, such as marginal land and/or rooftops and the like, which means real economic growth potential.