[tzs]

The atmosphere does a pretty good job of mixing, with the CO2 concentration uniform to within +/- 1% around most of the world so if there are enough places with stranded energy just building DAC plants there could help the whole world.

If there aren't enough places with stranded energy maybe we can make more. All that takes is installing more solar in some place than there is infrastructure to transport the electricity out. That excess is stranded.

The amount of energy available for solar is insane. To illustrate how ridiculously abundant solar power if you wanted to build a solar farm whose output during the day matched the power use of the entire world you'd only need about 500 000 km^2 worth of panels.

At night the power falls to near zero, but so what? If all it is doing is running a DAC plant it doesn't need to run overnight.

I'm sure there are hundreds of places around the world with good daytime sunlight, enough room for a DAC plant and a solar farm to power it, and limited grid infrastructure.

[mucle6]

"Only" need about France (~551,000 km^2) worth of panels. I see your point though

[tzs]

Note that is how much is needed to produce an amount of energy equal to the current consumption of the entire world. It is to illustrate how abundant solar energy is.

That would be enough energy with current DAC technology to remove each year about 50% of the year's CO2 emissions. That would effectively knock us back to 1970 levels of net yearly emissions.

There are 5 subtropical deserts in the world with areas greater than 500 000 km^2. There's room in those 5 deserts for about 30 of those 500 000 km^2 solar farms. That's enough energy to in 1 year bring atmospheric CO2 down to around 320 PPM, which is around 1960 levels. 2 years to get back back to 1800 levels. 6 years to get to pre-industrial levels.

Of course it is possible that at that scale energy isn't the bottleneck for DAC. It may depend on other resources that cannot scale that well.