From the article:
"Algae, like all plants, feeds off of CO2, water and light. A fraction of the energy in the light it absorbs is used to convert CO2 and water to the carbohydrates (carbo=carbon, hydrates=water) it uses to make more algae. In the process it produces waste oxygen.
In darkness plants metabolize some of their carbohydrates for energy to stay alive, and produce CO2, water and heat just as animals do.
georgehapplegate in reply to DcHewlett (Show the comment) 4 hours ago

<LI class="comment yt-tile-default " data-author-viewing="" data-id="CrwUV6K28QDi6W8mGecigSGxOa1UuPStvbv5BHBVAD8" data-score="0">Do the math. Growing algae with artificial light will generate more CO2 than not growing algae. That should be obvious.
You ask who cares that growing algae blocks the light? Ensuring the same level of illumination means using more artificial lights. You could argue that: street lighting and interior lighting is unnecessary, so why not just use them to grow algae? Why not just turn them off, and actually reduce CO2 emissions?
Think it through."





Nothing's free. Now, if they were using sunlight on vast pools of algae for the express of adding O2 to the atmosphere, ok, but burning a fossil fuel or using atomic energy? Ahhh, not so much.