here it is maybe a bit easier. also getting some "financial support" countrywise but also gettings some good and maybe more or less free credit from our bank. when i remember right, i was paying 185.- € / month for a credit at the solar panels and getting 225.- / month from our powercompany for "selling" our produced eletricity into the power grid. so after all i made 40.- plus each month plus the use of the electricity we are using for own consumption.
but as you said, this is only a countrybased thing and each country had other baselines for the support.
the other part with the ground-to-water headpump was all in all a much higher invest ( nearly 40k ) because we planed this as we built out house and also included a better house insulation, underfloor heating, energy saving house and other things.
but at the end, we are running our house with around 40.- euro / month costs for ( heating, water, energy )