> There is no point at which sequestering CO2 by use of electricity is going to make sense.
> Until the day that we burn zero CO2 whatsoever
That day will come. And we'll then be at the point where its time to use cheap renewables to pull CO2 back out of the air and store it in a stable state where it can't be burned again.
My bet is some sort of synthetic bio-augmented photosynthesis process (if you think about it - that's exactly what plants do - sequester carbon dioxide in carbohydrates). If we are super lucky that process will also generate edible byproducts.
> Until the day that we burn zero CO2 whatsoever
That day will come. And we'll then be at the point where its time to use cheap renewables to pull CO2 back out of the air and store it in a stable state where it can't be burned again.