Best technology for coal electricity capture costs $10/watt (close to new on budget nuclear plants), and only captures 65% of emissions. A better “free” climate strategy would be to put them in “backup peaker” mode for renewables and run them at far less than 35% of year.

DAC can work only if price of carbon is $300/ton ($3/gallon gasoline). Still, 100% renewables is cheapest path to avoiding those taxes, but afterwards, DAC can hope to pay for itself.