This story was originally published by Vox.com and is reproduced here as part of the Climate Desk collaboration. Every day, the sun’s rays send 173,000 terawatts of energy to Earth, 10,000 times the amount used by all of humanity. Which is to say, the potential for solar energy is immense, and we’re nowhere near the limit. That’s why solar energy is such an appealing prospect, particularly as an alternative to the fossil fuels that cause climate change.