A solar-powered oxygen producer. Instead of huge solar farms in the desert generating solar electricity, then transmitting it hundreds or thousands of miles to where its useful with all the losses involved, instead directly generate oxygen from sunlight right there. Doesn&#x27;t matter where you do that for the planet; once up and running it&#x27;ll help sustain the whole world like a rainforest does. And it could be massively more efficient than growing plants. And it could work where there&#x27;s the most sun and the least opportunity for plants to grow - large deserts.