The most cost efficient new-build grid is 90-98% solar/wind/battery depending on your locales insolation & wind coverage. (Source Ember Energy) The remaining 2-10% is nat gas, if you have a piped source, or coal if you don't.
But 98% renewable doesn't mean you can hit 100% by adding 2% more of something else, it means your something else has to supply ~100% of the power 2% of the time.
If China is aiming for that cost-optimal 90-98% renewables, that means they need to build a lot of coal.
But 98% renewable doesn't mean you can hit 100% by adding 2% more of something else, it means your something else has to supply ~100% of the power 2% of the time.
If China is aiming for that cost-optimal 90-98% renewables, that means they need to build a lot of coal.