Well, my brother-in-law is a building services engineer with 35 years of experience and wanted to install such a system for his son (also in the industry, but with a bachelor’s degree ;)). Planning started around 2019. I don’t know if your mentioned system already existed back then. It is definitely still experimental, but that’s no reason to say “leave it”! They also had offers of similar size back then, but hydrogen tanks installed outside. It then failed due to binding commitments regarding consumption and performance. I did a plausibility calculation at that time (photovoltaic yield, hydrogen energy density, electrolysis losses, etc.) and hardly found any cold months that could be bridged (the calculation clearly showed that it wouldn’t have worked!). I can hardly imagine that so much has changed in two years, but on paper even “snowball schemes” look good at first. Also, as others wrote before, I see clear divergences between wishes and budget.
There is the company HPS Picea in Brandenburg, almost near Berlin.
They are now providing guarantees.
There are already videos online where users of this system report that they can easily manage an entire year with it.
Our planned system with the 110 K is also calculated here to be above average in size.
So in the end, we would also have about 6-8 external hydrogen composite tanks that initially store the hydrogen using energy from the roof.
This means we want to deliberately overestimate the storage capacity here to be able to bridge dry spells.
In other words, we want a bigger system than the one HPS calculated for us, because we think just like you do.
Nice numbers, but better to be on the safe side.
Normally, a system costing 60 K € would have been enough for the house idea, but since we will probably overestimate the electricity consumption alone compared to most, we are playing it safe here.
For all emergencies, at least the electricity connection should be routed into the house.
The system would pay off given our electricity consumption.
And aside from that, we would have a CO2 footprint from the house of virtually zero...
So we would even be doing the environment some good if possible.
We are not really eco-freaks and that is of course not the main reason.
However, if we are as energy efficient as possible and for electricity ideally only have maintenance costs in the future instead of monthly rising costs, we save enormous amounts of money.
If the house is sensibly and efficiently built, we also waste nothing. We have zero heating costs, meaning on average my parents and their friends pay around 400-500 euros per month for electricity and gas with smaller square meters. We, on the other hand, would have much higher costs due to larger square meters, which we (apart from the loan for the system) set to zero.
I’d rather put the 400 euros without price increases over the years into a loan and then theoretically be cost-free in old age with only maintenance and repairs left.
(Of course, such systems also age, but by then these systems will certainly be cheaper, and the electricity and heating costs we would have saved should not be forgotten :) We’d rather invest that in extravagant hobby enthusiast technology ^^)