I think this is wrong in terms of new build cost. Especially if you take away subsidies. As far as I know, local factors aside, wind gen costs around 1500/kw without storage. Solar is similar, and gas is around 1000-1200 for a combined cycle and 800 for a simple ct (which would likely be a peaker). If I am remembering correctly, Duke energy recently completed a combined cycle plant that came in significantly under cost - around 900/kw.
If you add utility scale batteries, you’re looking at much more for renewable. I’m not sure what type of storage you have in mind though. Add to that, the capacity factors are very high for gas, while notably low for renewable. This impacts payback severely and I’m not even sure if you can sell capacity against a renewable plant - I may be wrong here.
What type of renewable are you talking about and what type of storage? Also what are the new build costs you are referencing? Or are you simply saying that a utility scale battery costs less than building a peaker?