Wait, it gets more expensive when you use more?

Net metering is potentially better, as you are effectively getting free night usage based ob day generation. My setup pays me, but I get paid 20c per Kw (NZ dollar) and pay about 30c to buy, so there's a 10c difference. Just as long as whatever you lose on 31st Dec is not too high, you'd be better off than me.

Net metering is great, much better than being paid for the surplus.

With net metering the grid is basically an free, infinite, 100% effective battery.

(Author here) Yes, this is how it works in the UK. I sell my excess electricity back to the grid. The selling price is a bit smaller than the buying price.

I'm very ignorant on this subject, but couldn't you just sell excess to grid and get it back for a minimal markup?

Sure, but it depends on the incentives in your country. Afaik, excess energy could be sold, but you'll have to checkout your local incentives and energy suppliers for specifics. In most parts of Europe, the are scaling down the prices for excess energy. Therefore, battery systems are being forwarded in some cases as sort of solution for solar panels maintaining like ca. 80% +? integrity efficiency over 20 to 30 years.

For example, I read that in The Netherlands the solar panel market has crashed completely or is crashing. Note here that saturation of the market ( many existing solar panels) can also cause that.

You need to find out;

1. energy usage
2. insulation options and materials
3. costs /benefits
4. energy contracts and energy incentives.
5. check out current physical electricity wiring and fuses in the house
6. DIY or professional?
7. budget etc

TLDR: dont buy solarpanels if you want to be rich. And buy them according and after you've done everything possible to insulate your house, whether in the colder or warmer climates. The efficiency, added value, and comfort reached by insulation outweighs everything else. Then , after doing that, check your kwh usage, and buy solars according to that.

Hope this is helpful, but seems you need to go outthere and do some exploration on the topic.

(Ed: layout)

It is not remotely close to economically viable to go off grid, and the exports of solar power to the grid pay for the connection anyway.
The reason to have a battery is that it lasts through the night, or even with a smaller system, it can handle dinner time, which is the most expensive time of day to buy electricity.
Now if you live in some remote area without a grid, a generator is a way better option than a huge battery.
Maybe if you live somewhere very sunny, like Spain and especially southern parts of USA you can probably do it with a modest battery that can handle a couple of days.
In the summer we can make enough electricity on by far the most cloudy days, but in the winter, the sun can't penetrate the clouds nearly as well.
Admittedly London is south of where I live, which is close to the most southern part of Denmark, but on the other hand London is infamous for grey weather with heavy clouds.

You could probably get by with a gas generator and only run it 2-3 times/year in many areas. It's not 100% green, but it could get you off grid for a fraction of the price.

OK I didn't see that, that's bigger than I expected, we make about 12.5 MWh per year on our 11.2 kWh panels = 1.1 MWh per kWh capacity.
Your system is 5.1 kWh but you only make 3.8 MWh per year = 0.75 MWh per kWh capacity.
Meaning we have 50% higher yield per kWh rated capacity!

So our production remains 3.3 times higher than yours, despite we only have twice the capacity.
But our panels are pretty optimally placed towards the south.

Considering you are further south compared to us, I'm surprised your yield is so low, despite London is infamous for being cloudy.

...maybe.

I mean it's probably their kids doing that.

could be because I told them I’ll buy once I can get net zero.

I'm not following your logic. You aren't willing to accept any savings unless you can completely zero out your power bill? Judging from your consumption I'm assuming a good chunk of that is for cooling your home? If so that means you're likely in a pretty great place to harvest solar power. You'd reach payback of your investment on your array much faster than most, and be saving money for probably 35 years or more with little to no additional investment.

Making some guesses for how much your electricity rates are, and how much you're consuming (assuming much from cooling), you might be a full payback in less than 7 years if you took advantage of the tax credit. Then, every month after that you'd be gaining money back.

is that per-month, or for the whole span?

Older house, poor insulation, 19 year old heat pump/AC, and hot summers.

It is. Some of them are getting snapped up to help with powering factories.

I think this is car companies using the incoming battery packs from replacing worn out packs. Time to look it up...

https://www.autoblog.com/news/toyota-just-found-a-clever-new-use-for-old-ev-batteries

This is the article I was thinking of. It's more of an idea than a common use case to use old packs to help power factories.

Using half-worn car battery packs seems optimal for home use.

I'm not putting cobalt based (NMC or NCA) batteries bolted to the inside my house. Thats nearly exclusively what car battery packs are. Thermal runaway is too great a risk to bolt that much energy to a wall in the house. I am comfortable with LFP in the house though.

I mean.. they are at ~$16/ kwh right now, so...

https://www.alibaba.com/product-detail/CATL-75AH-220Ah-Grade-a-Sodium_1600972483761.html

No?

O, absolutely. The reality is the only reasonably economic way to do off-grid is with solar, battery, and a diesel or propane generator to top off the batteries when solar isn't cutting it.

That's because they are big mechanical whirring machines. Solar panels are dead quiet and don't throw intermittent shade and have a very low risk of causing damage in the surrounding. There's good reasons they are forbidden for the average household to put on top of the chimney...

These are called "storage heaters". They're still available. https://www.which.co.uk/reviews/home-heating-systems/article/home-heating-systems/storage-heaters-aokoz3G2Em9L

Very old heaters used to contain lots of asbestos. It might have worked well.

Suburbs are fine for district heating, but it's a massive long term investment.

For UK in particular, I also think proper insulation and triple/quadruple window panes are much needed to curb with the increasingly scorching summers and freezing winters. I was surprised to see soo many houses with single paned windows in London.

you really need scale for sand batteries to work

Not at all. First, (hot) water batteries are excellent for home heat storage. Sand/dirt is even more storage per volume required, and completely complimentary in sending hot water through it (pipes) to make it hotter. No combustion heat means less air exchanges, and a 300C rock/dirt/sand pit has losses that radiate through house.