I was going to suggest we should hold competitions for turning Earth's CO2 in sugar as well, but then I remembered you can just plant seeds.
It's literally dirt cheap and super easy in many parts of the world to drop sugar beets in the ground at 40 acres an hour. Photovoltaics (not even considering the chemistry equipment) to cover an hour's worth of planting will cost on the order of $20 million!
Hmm, I wonder if there's a market for that...
Most plants need some oxygen for the root network, but photosynthesis produces an excess of oxygen and doesn't require it to run.