This is only the capex of the project. Tesla batteries can be...

This is only the capex of the project. Tesla batteries can be expected to degrade 7-10% over a period of 10 years.

https://electrek.co/2018/04/14/tesla-battery-degradation-data/

This equates to swapping out 7-10% of the batteries over 10 years if amortized over the same period, equates to 0.7% to 1% per year. $15-20M replacement cost just on batteries every year? That adds another $150k per MW a year. Run the same setup for 6 years and you could have build another gas plant. In fact, you could have built a gas plant every 6 years with the amount of expenses you incur.

A gas plant on the other hand, lasts for decades.