Why is pure CO2 not used in solar power?

Question

If atmospheric CO2 acts as such as heat trap for infra-red sunlight in 300-400 ppm, why is pure CO2 not used in solar energy?

Answer 1

It doesn't happen here because of the plants recycling the CO2.

Answer 2

Because solar glazing, either glass or plastic, is much more effective at trapping heat.

Answer 3

How do you propose that would work?

Think about it - over the past 150 years atmospheric CO2 levels have increased 37%.  This increase has caused the planet to warm about 1°C.  Now for the global climate, that's a huge change.  But if you just trapped 384 ppm of CO2 in a small area, it wouldn't absorb much heat.

The radiative forcing of CO2 at its current levels is 1.6 Watts per square meter.  In other words, you need about 15 square meters just to power a CFL.  It wouldn't work on a small scale.

Answer 4

"Solar power" converts visible photons into electrons using photovoltaic materials, mostly.  CO2 isn't a PV material.  If you mean solar power in terms of heating hot water, and using the hot water for power.  In that case, CO2 doesn't absorb enough of the incoming shortwave solar radiation to make that worthwhile using CO2 as the absorptive media.  Typically water systems use dark backing that absorbs the shortwave energy, converts it to heat, which heats the water lying on top of the black material.  If you want to use CO2 instead of water as a heat sink in that type of solar energy collector, there are better gases to use, sulfur hexafluoride for instance.  

The fact that CO2 has marginal use in industrial applications as a radiatively important gas doesn't mean it is irrelevant as far as the planetary energy balance is concerned.