when we had our solar and PowerWall setup installed we pondered if it would ever be justifiable financially but did it anyway on environmental grounds. it’s panned out rather well.
Me too. Everything Green I have done has paid off ... although, at the time, my mates mostly rolled their eyes and on the floor ... then subsequent turned green (colour, not environment, sadly)
Back in 2009 replaced failing oil boiler with biomass (logs), accumulator and solar thermal. Hugely expensive, wife and I sucked our teeth a fair bit, but I didn't want to buy another oil boiler and be stuck with it for 20 years. By following winter the price of Oil had gone up 70%, by the next winter 250% where it stayed for the next 5 years. That paid for the increased cost of my green-option, over a straight oil boiler replacement.
Had several VW Blue Motion Golfs in a row, then discovered that I had been lied and cheater by VW Dieselgate. In 2015 looked around for alterative and discovered that Tesla MS had a 250 mile range. 3x the price of the Golf and all the concerns, back then, of range and charging locations (I was doing 30K miles a year, out-of-range 2x a month). Saved a bundle on fuel (charged at work for free), BiK tax, servicing (didn't bother with servicing at all for final 50K miles). When I traded in after 3.5 years / 100K miles the new MS was 20% cheaper, 20% more range, and got a 50% trade in . At that point the TCO looked pretty rosy ... and AutoPilot meant I arrived a lot more refreshed on all my long business journeys than before - so add to TCO the reduced wear-and-tear on the driver. And 8 hours a year not stood on forecourts filling / queuing to pay. My Man Maths says those are "billable hours"
Added PowerWall in 2019. Hugely expensive ... (use more leccy than normal because I run business servers in the house), on sunny days Spring-to-Autumn charging the battery overnight bridges with the 16 panel PV so day usage is close to zero. Just having a further 32 panels commissioned - should then be able to charge the battery from PV most days Spring-to-Autumn, and a Zappi added for trickle charge of car with any excess.
Improved house insulation too - too difficult to radically improve the main part of the house, so built a Passive House extension, which has the main winter living quarters. Increased house footprint by 50% and overall heating fuel reduced by 50%
by turning down thermostat in old part of house a couple of degrees as we are not sitting still there on winter evenings and improved insulation / air tightness where I could
All that lot has cost me a lot, at the time the payback on them looked dreadful (like you I was doing it on environmental grounds). One event or another has solved the payback for me ...
Small print: historical performance no predictor of future profitability ...
