Lets compare that Clean Coal power station to the Crescent dunes solar thermal power plant in Las Vagas (all figures approx and off wikipedia)
Boundary Dam (Coal) Capex 1.5bn Canadian dollars = $1.22 billion US, for 110MW.
Crescent Dunes Capex $975 million US, for 110MW
The solar power station obviously has lower Opex as it uses, like, free sun, rather than coal, and doesn't need to spend lots of money capturing CO2.
And it has almost zero emissions, as opposed to 50-90% of what a normal coal power station emits.
So other than ideological arguments, and an attempt to shore up an industry which is unfortunately past its sell by date (neither of which big financiers give a rats ass about) , why would anyone invest in "Clean Coal"?
