For fun, put a nail in dirt. See how long it lasts.

But there is more to it: The stake has to have permanent contact to some electrically conductive layer in the ground, so you need to take geology and local climate into account. In central europe, with generally wet climate, you just need to reach the year-long stable, frost-free, local water table at a depth of (usually) between 1m and 10m. If you cannot reach sufficient depth, don't know the required depth, a simple stake isn't going to cut it. Because in case of an electrical fault, the grounding has to withstand and dissipate in the order of a few hundred Ampere. To achieve that you then shallowly bury lines of non-corroding material in a grid, or bury a grounding net something like 1 to 2m deep over an area of 100m^2 to 10000m^2.

If you are on sandy or rocky ground, permafrost, arid climate and no handy body of water is nearby for grounding, you need to have a far larger grounding net or use conductivity-enhancing methods like permanent watering, adding salts or carbon to the soil or replacing it outright with something more conductive. In all, very expensive.

And as for large installations, you just measure the soil conductivity, calculate the necessary grounding current and scale up the aforementioned methods.

Disclaimer: Not intended in any way as professional electrical advice yada yada. Just what I've read.

(Also all sorts of weirdness can take place around grid earth vs. local earth, eg. during thunderstorms. Earthing is its own entire engineering discipline. :S )

Well, I suppose if you have enough panels to generate power even on short, cloudy winter days, then that doesn't matter anymore; then you just need enough storage for the night. But then what are you going to do with all the surplus power on sunny summer days?

Some sort of cheap long term storage would really help a lot.

It's not terribly sophisticated, but it keeps my pipes from freezing.

Refueling a car is as easy as it gets, though. To refuel anything else, you'd have to put it in a car and take it to the fueling station anyway. This way you just refuel the car the normal way. You can also store whatever gasoline you'd have used in a generator at home too, but the Prius' 10.9 gallon tank holds a lot more than your average portable generator and runs a good, long while.

Now I'm in single family home and my energy use is bonkers, but most of that is heating while I'm missing part of my roof and an entire exterior wall. It should be criminal for a town to take two years to approve permits.

I've installed an electricity meter 2 weeks ago, and the lowest it got was 4,8 kWh/day in a 2-person Croatian household, although I do have a small Synology NAS running 24/7 and we have a TV on for a couple of hours.

Easy, live in a house 4x the size of a 2-person Dutch household and in a climate that averages 10 degrees C warmer, like would be common in the southeast US.

Do you mind shared where this is?

Unless you meant 100 kWh/day, which would be doable, but I think only with geothermal.

The most rigorous standard for home efficiency, the Passive House standard, stipulates that no more that 15kWh/m^2/yr is used for space heating. For a 200m^2 house, that's 3000kWh/yr.

Given a 120 day (4 month) heating season, that's 25kWh/day average just for space heating. Obviously it varies quite a bit, with some days much higher and others much lower. Add in other electricity uses, like refrigeration, laundry, and you're easily at 40+ kWh/day even in an efficient Passive House.

Apart from heating the house, we also use some power for hot water and pumping water from the well into the house.

Not much even in an efficient house.

We didn't build the house, so there are all kinds of standby stuff (including needing smart lights for most lights, stove, towel heaters).

I didn't turn these things off because my mother in law is using the apartment a little while we are gone.

My 200m2 house is slightly worse at ~120kWh/m2/year, or around 24MWh of energy per year (that also includes domestic hot water though).

With a ground/water heat pump it should translate to ~5MWh of electricity per year, or about the same as my current yearly electricity consumption.