Maybe not that far apart. The challenge with subsidies is the administration and making sure you exhaustively subsidize different options. It’s also infeasible

Maybe not that far apart. The challenge with subsidies is the administration and making sure you exhaustively subsidize different options. It’s also infeasible for smaller investments such as radiator foil. My underlying assumption is that you would reduce the 2k compensation in my example. So the incentive for any saving remains. On duration: I installed solar for 0.80€ (ex vat) per Wp (which generates about 1kWh p.a.). In NL electricity rates recently spiked to 0.45 euro per kWh. Based on that, payback time is now less than 2 years (that includes everything, panels, inverter and installation, etc.) but I think we agree the challenge is to find a way to create a good market incentive for consumers and industry to reduce their externalities/CO2.