Start with the actual structure of your expenses
If your household spends mainly on electricity, solar works immediately. If a large part of budget still spends on gas, oil or fuel, solar alone protects less. It is then necessary to read as a first brick in a broader strategy.
What causes the protected portion to vary
Three variables dominate: the size and orientation of the system, your self-consumption rate, and the level electrification of the building. A house with heat pump, controlled water heater and electric car plugged in during the day gets a lot more value from the same roof.
The right objective: cover a significant and predictable portion
Seeking total independence often leads to oversizing or overinvesting. The intelligent goal is to protect a significant, stable and profitable part of your bill. This is already what is concretely changing your exposure to future increases.