Found this article
https://www.abc.net.au/science/articles/2012/04/17/3478276.htm
And it looks like it's saying that the energy produced by nuclear fusion (which happens in the relatively small core) divided by the entire mass of the sun, gives you that low number.
Terrestrial fusion power plants are aiming to be sun cores, so that all the hydrogen they put in gets fused, and not just a few atoms here and there.
We should do both
There is no two.