Energy prices are high in my country, and price spikes have become more frequent.
My house is currently heated by natural gas, which costs about €200/month avg plus another €550/year in standing charges. Prices for natural gas is expected to rise. By switching to heat pumps and induction cooktop I can disconnect from the gas distribution grid completely. This will safe about €3k in gas costs annually (against current rates) but obviously increase my electricity usage significantly. So in my country €5k/year in electricity isn't as ridiculous as it sounds.
I'm projecting my electricity consumption to be ~€3.5k a year once I have fully switched to electric heating, so this is where generating my own electricity starts to make sense.
The PV array I'm planning is very much over dimensioned for my use. To make financial sense my PV installation must produce more than I consume over the year. Not only will my electricity bill be effectively €0, I will also be able sell overproduction back to the grid during summer. By using variable rate discharging I can optimize the return. I am projecting that selling overproduction will net about €1k annually.
The rest comes from from dynamic energy tariff trading. The battery will be used as a grid stabiliser, so it'll charge (from the grid) when electricity is cheap/negative and discharge back to the grid when return rate is high. This is projected to net another €500~€1000 annually.
If I add an EV I'll safe about 3k/year in fuel, though my electricity use will obviously go up, I won't have as much overproduction anymore.
In my country PV only really makes sense when it's combined with batteries and connected to the grid with a variable rate contract. The more battery capacity you have the more value/income it can create stabilising the grid. So really the price per kWh of battery capacity is the driving force in the ROI of a PV setup.