Emergency power supply for oil central heating

Well, these are all good and important points from you. You never really know how likely something is to happen, and how severe it will actually be. And of course, you also have to distinguish whether we're just talking about a certain loss of comfort that can be somehow compensated, whether we're talking about a serious danger to the building, or whether we're even talking about a serious threat to societal peace.

I fear that when you prepare for any scenario, in practice it turns out quite differently. Or in the best case, we are completely spared from such problems, then the corresponding money was just wasted.

Difficult...

Matthias

If you want to get a generator, I would recommend a diesel generator. Because if you have an oil heating system, you also have enough diesel (heating oil) for the generator in case of emergency. I know now they say you are not allowed to do this. But if it comes down to it, I wouldn’t care as long as I have a warm behind.

Of course you are allowed to do that. A diesel generator is not a vehicle, but a stationary engine. You are allowed to run it on heating oil without fear of trouble from the tax office. It just should be able to handle (relative to today’s diesel, but not diesel or heating oil from 30 years ago) sulfur-containing heating oil.

If you have an oil heating system, I would also take a diesel generator since there is enough fuel available. Otherwise, use a petrol generator. In the worst case, pump fuel from the car... The most convenient is a stationary installation. However, it is quite complex and expensive. Heating oil may then also be used for this. In a crisis, most people wouldn’t care... What must absolutely be supplied and what not? The generator must be sized accordingly. Is single-phase sufficient or is three-phase needed? How are personal protection, grounding, isolation from the grid, etc. ensured? If the power really goes out for 3 days, there will be many fires. People will start doing the craziest things then. I know some who already have emergency plans for the family. Everyone living in multi-family houses first flees to relatives with single-family homes, preferably in rural areas. Enough water, food, warmth, electricity, and firearms for defense. I really don’t want to paint a gloomy picture here, but you should definitely think about it a little. A small generator to operate the freezer and heating is certainly good. The consumption is quite low and it doesn’t have to run 24 hours. The refrigerator is also important, but in winter the balcony suffices (if it is not easily accessible). When we built, we decided against an emergency or backup power supply. At my mother’s place, I start the unit 1-2 times a year. So far, it has only been needed twice. Hence our decision against it. By now, I would decide differently... Meanwhile, there is a generator here that can provide emergency power. Our installation allows for easy integration. It can also be operated in a protected area and is thus less vulnerable to attack. I hope that we will never need it for several days. If the power goes out for longer than a week, looting will start...

I do have something like that, but that would actually be the most inefficient solution. And you have to have enough Aspen gasoline on hand, because otherwise the device will gum up after years of not being used. Therefore, only Aspen.

By the way, there haven't been any cars in my family for years where you have to pour in any fluids...

Aspen is not necessary. SuperPlus without E10 has been proven to be stable in canisters for over 15 years…
There are also additives for diesel.
As you correctly recognized, you won't get far with a battery. Since you apparently have electric cars (which also have windshield washer fluid, coolant, brake fluid… in them), you could tap from there. There are a few videos online about this. But it's not really recommended.

SuperPlus without E10 has been proven to be stable in canisters for over 15 years…

Really? I’ll have to look that up again. I think I read something about "stable for up to 6 months." Otherwise, definitely all good points.

But just to mention it for the sake of completeness: If three-phase power is fed into the house, then the generator must also be capable of handling unbalanced loads, otherwise you can quickly fry all the devices in the house due to over-/undervoltage. The cheaper generators with CEE sockets often are not, and voltage stabilization is only available for the first phase, which is also where the Schuko sockets are connected. The manufacturer then assumes that only an electric motor (e.g., a concrete mixer), which does not produce unbalanced loads, is connected to the CEE socket. The datasheet often states "200% unbalanced load capable."

Cheap generators are not suitable for something like this. Even single-phase ones do not produce a clean signal. Many also fail after just a few hours… Good generators are 25% capable of handling unbalanced load of the total power. Usually, they are already five-figure priced if you really want backup power.