Re: Your figures like many
So, your totally offgrid, in that the electricity from solar panels is going to batteries and your then drawing that power from the batteries at night to drive an inverter, which pushes the power into a step down transformer to charge another set of batteries. Many of us actually here of course are IT Professionals and have setups capable of delivering many kilowatts at 240 volts at work for keeping servers online for mere minutes, so we know:-
1) How much it costs to deliver multiple kilowatts from batteries for long enough to fire up a generator, let alone to deliver this sort of power for multiple hours.
2) How much physical space the transformers and batteries require.
3) How much this lot weighs and how much structural reinforcement is required to put them on the first floor of a building.
4) Misc things like the amount of hydrogen generated from the battery charging requiring either spacing or ventilation to avoid a fire risk, the maintenance required, and the cost of new batteries when used frequently.
You may suggest that your doing this, but I don't beleive you, sorry. Especially when you need to say that as an Anonymous Coward. Nor do a lot of other people, judging by the downvotes. We don't beleive you because we know full well that most modern houses barely have enough room for the people to live in, let alone have space to fit this sort of equipment anywhere but the loft space, which is made from wooden beams in most houses, which is rather more flimsy than the reinforced concrete that we have to get reinforced to take the weight of large UPS systems.
If you were doing this then it'd be because your very, very well off and can afford equipment our companies can't (plus the room to install it, which our companies couldn't in offices which are much bigger than homes), and you'd understand that:-
A) it's not a solution viable for any significant percentage of the general population as the cost of the equipment is much greater than the yearly income of the richest 10% of the population.
B) The usual setup with solar panels is that you sell the generated power via the feed in tarrif scheme during the day for profit, and then buy electricity from the grid when you are at home. The feed in tarrifs are greater than the normal cost of electricity so your use in the evening is paid by the power sold in the day resulting in payments from the electricity company, rather than you making payments to them. This is then recouped by pushing everybody elses electricity bills up, so the old and poor who can least afford it pay more for electricity to pay for your electricity.
C) The power that you, and all other well off/rich people with solar panels on the roofs generate is not enough to turn a real power plant off during the day, so the electricity still has to be generated centrally both during the day and in the evening meaning that your input doesn't significantly change my very, very rough estimate as to how much power is required from the grid.
I expect that my estimates are way out of kilter, as I note with things like not taking into account that there are likely to be 20 million vehicles needing charging at about 5% rather than 2.2 million at 100%, but your input doesn't add anything to a reasoned debate on this, sorry.