With all due respect these are the kinds of "tiny" details that renewable enthusiasts conveniently forget. Yes, this person's house needs better insulation. As does everybody else's.
You can't just wave this away with "your math is wrong". These numbers reflect reality, not wishful thinking.
I think for me and the OP it’s quite clear that optimizations can be made on production and consumption side. And in their circumstances financial reality says that increasing production is much cheaper, while possibly providing extra cash that would enable investment for reducing consumption, which in turn would lead to more income.
The problem with people enthusiastically proposing renewables as the cheap solution to our energy needs is the thousand "little" details like the one above. Whose only mention is in the comments like "your math is wrong, invest in insulation".
No. The math isn't wrong. Bo, the consumption is correct and shouldn't "should be lower". Because it's directly indicative of the reality.
Yes, you have a couple of enthusiasts who can sink another X kiloeuro into rebuilding their house. For the absolute vast majority of users it's not a viable option.
So yes, the answer to "PV energy is almost enough in summer and not nearly enough in winter" isn't a dismissive "you're doing insulation wrong".
I shouldn't put solar panels on my roof because it would not fix someone else's problems? What kind of logic is that?
So that's an actual solution to the problem!
Only if the efficiency is 100%. In practice it's lower than that, so reducing consumption is better than increasing production.
The expected economic lifetime of a building in Germany is approximately 100 years. Which means that on average, the house will be torn down and rebuilt after at most 100 years, because additional upkeep would not make economic sense.
This means that if you do not change policy except mandating modern standards for new buildings (which is already done) and do literally jack-shit, the normal economic activity will have the problem sorted out in that timespan.
For reference: Of 22 million buildings in Germany, "only" 12.5 million are built before 1977.
The German government aims at having pretty much all buildings energetically renovated in 2050.
The biggest problem is that 1. there are many house-owners who literally do not give a shit even if they can save lots of money by an investment. Not everyone is economically minded and there is no political will (or legal basis) to force these people for their own good. And 2. for bigger apartment buildings etc. it is hard to do an invasive renovation while the units are occupied, limiting the scope of renovations to something that can be done in-place or one unit at a time or without affecting tenants.
Citation needed. This number is absurd.
Of course you can only do that once. And if you’re a landlord why would you pay your money to insulate when you wont save any money as your tenants are the ones paying the bills.
I mean generally it is well known that you cannot just put a lot of PV/Wind and things will work. A smart grid is needed, buffers and ideally great insulation although that is arguably important for every form of energy. Also at-home PV setups are meant to earn money/offset the energy bill. Autonomous energy supply is an after-thought that is interesting enough but has obviously not been possible with any other energy source before actually.