It is not maintenance. An AC grid is a complex beast that needs to continuously match power consumption with power generation. When you add an intermittent sou

It is not maintenance. An AC grid is a complex beast that needs to continuously match power consumption with power generation. When you add an intermittent source like solar that has its peak production about noon you’re displacing baseline generation in favor of dispatchable sources like natural gas. Besides, the operator is forced to buy your energy paying a price a lot higher most of the time, and indeed at some periods in the day the power generated by your solar system has negative economic value, and yet the company is forced to buy it from you at almost consumer distribution prices instead of buying the same power cheaper in the spot market from some baseline generation facility.