Green Energy

I was thinking the same thing. But on closer reading I see the article makes comparison to renewable energy production capacity in the area. So I think by "capacity" they do mean power, as in the project's contribution to the grid's power delivery capacity.

All of the information I found on this project comes from an article from the [South China Morning Post] (https://www.scmp.com/news/china/science/article/3230622/china-breaks-ground-major-project-could-boost-renewable-energy-production-gobi-desert). The Interesting Engineering article copies some passages, including the source article's choices of the word "capacity", and the use of "20 million kilowatt hours".