Powered solar heat pumps sanitize themselves once a week if temperature doesn't reach 70C at least once. Same for heat pump boilers, they are usually set to 50C but goes up to 70C weekly.
On solar, there is always a downstream heater that can heat cold water to 60C+ and must be set at least that high for legionella. My setup is like that, unpowered solar tank for free heat if available, and gas boosts it up to safe temperature and does all the work in the winter.
[citation required]
Unsubsidized PV is around €1 to €1.5 per Wp, IKEA offers 4200 Wp for €4321 right now. That saves at least €800 off my power bill.
A solar boiler starts at €2500 at minimum and easily goes up to €4000. It saves me €250 per year in gas. Or I could get a heat pump boiler for €1500 and save 80% of the €250.
Thermal solar was a thing when PV was stupid expensive but it makes no sense in ROI now, with PV you can power your hot water, home heat and everything else for about the same price as 2-3 solar heat collectors and a boiler.
What crazy ass compressor needs 220V 30A? Here in Netherlands heat pump is standard as new gas connections are banned for environmental reason, and most homes heat water and the whole house on 7 kW heat, 1.5 kW electric, or about 7A on 240V.
The backup element which only runs at extreme cold outside is a few kW yes but for hot water we just let it run dry and the tap gets colder, no big deal.
Dedicated hot water only boilers have a 300-700W compressor and sometimes a 1.5 kW backup coil. If electrical connection is an issue, just look for a pure compressor driven boiler.
If you print regularly, HP's 6 cent per page, 100 pages per month plan is about the same price as a small black and white laser's drum and toner.
But you can plan full page photos on photo paper with it for that 6 cent too, not just BW documents. I like it, a full year costs about the same as 1 set of XL OfficeJet ink and you never have to try to save money by going BW / draft mode. Just print whatever. Clean the head whenever needed. It's all included.
Yes it is a subscription, but this one is actually useful. And it gets cheaper the more you print, up to small office volumes. We have it at multiple offices on a 300/700 pages plan.
Efficient with money means you get more of that world and environment as savings per dollar.
Would you choose paying €4000 to replace 600 kWh of heat pump boiler hot water with solar boiler, or 4000 kWh of basically a whole home's energy usage including hot water?
The solar boiler doesn't even heat well during all seasons, mine still uses gas to back it up at least half the days.
We have two main models here, one with a sizable compressor enough to heat a whole home (7-20 kW heat) and a water tank on the side which doesn't need resistive backup, or smaller, hybrid models that have a few hundred W compressor and maybe 1-3 kW heat output. The latter are almost all backed up by a gas boiler in a hybrid setup, usually uses zero gas until you run it dry - then the 25ish kW gas powered furnace can provide enough power to quickly fill a bath or send tons of hot water to a rain shower.
Chosing to eat chicken instead of beef impacts the whole chain from fertilizer to animal feed to clearing the Amazon for pasture to methane produced by cows.
You have more choice than you think, like which meat to pick or to use more eggs and cheese as replacement instead. This is just one of the obvious everyday choices. Not all fish is equal too, with sustainable aquaculture being the best choice for the world.
If the oil majors, or just one of them switch off the taps tomorrow we will just get Russian gas crisis x10 and make OPEC and friends insanely rich. We need to transition to something else, that's for sure, but blaming them for everything is super naive.