SteamyTea

I do my own, mirror and camera. Even got an attachment to trip orifices. Very good it is. Think it cost a tenner in The Middle of Lidl.

Property is £120k, different market entirely.

Can you clad that side?

Caravan makes sense to me, especially if you fit an A2AHP to control the climate on the cheap.

1 down here.

So 12k a year, your build will probably take 3 years. So about equal to your current savings.

Nor are your reading skills.

How much is the rent?

I was being ironic.

No, PVGIS assumes 14% losses on the PV side, probably similar on a DC side. But I was making an Anti-Sales pitch. Batteries are all the rage, and tomorrow there will be a 'game changer' i.e. V2G, Hydrogen, novel chemistries....

It can be scaled though by multiplying until it gets to your usage. There may be marginal saving to be made on the system install prices. My savings are made by not importing a lot of the time, last week was 49%, made up of 43% over the night 7 hours and 52% over the day 17 hours. That saving has probably cost me less than £100 for a few timers and the monitoring kit. Been making those saving for the last 15+ years now. I suspect that having PV and battery storage makes people a bit more prolific with their usage as they think it is cheaper, so a lot of double counting goes on.

But you will have spent quite a few thousand quid on a system to mitigate against price variation. I use about 1.3 kWh/day, consistently, the rest of my usage is at night (remember I ma on a basic E7 tariff). If I charged up at night, say 2 kWh to cover losses and variation, then that would currently cost me 30p a day. Say I could get a battery system installed that can store that amount for £2000. £2000 / £0.30 = 6 years 7 months How much would I save at current prices. Day rate is currently £0.486/kWh, so on average, and my day usage is pretty consistent, £0.63/day, an increase of £0.33/day. £2000 / £0.33 = 6 years. There are some big assumption there, fitting a system for £2000, highly unlikely, and energy prices stay at todays relatively high amounts. To be realistic, the system would have to cost around £500/kWh. And even then it is marginal and relies on a £0.15 to £0.2 price different between day and night rate. I am not, but we can look at historic 'half hour' rates and adjust to today's prices. You are the programmer, so write something that will link to this https://www2.bmreports.com/bmrs/?q=eds/main

That is population, not housing, as you claimed. I do agree that there is probably a good correlation with population and water usage. It may be a case of not potable water being a problem, but waste water not being treated effectively. We just flush it into the sea down here.

Shall I point you to your topics about battery storage and adding extra? You use a combination of PV and one of the many, confusing, Octopus tariffs to charge your batteries. Now I admit, that you are selling some back to Octopus, but that is a very short term benefit, come winter, it will cost you I suspect. But as you said about the car, if you want something, then you get it (mind you there are many think I want, but have no hope of getting). Regarding the 'how much hot water do you need', that has been answered nicely by @Marvin. Enough and only a little more. As for having batteries charged up 'to use with anything', it is an expensive way to heat water when you need it. A 12 kW shower will soon gobble though your battery storage, and that assumes they can reliable deliver that sort of power. Do you know the cut in power your SE/PW systems needs, will it run 20W of light bulbs? Or 10W for a laptop? Many systems won't. Was it @Radian that showed a chart of his inverter getting confused when the induction hob was on? I can't remember. That bit is true, but seems to have been answered, finacial.

Stop mucking about, you would have all the storage in the nation if you knew the difference between Kw and kW/h.

Bonjour. Sound a sad situation. I suspect the first thing to do is get a valuation. Then look at the taxes, France has some odd ways with properties, well they did 40 years ago when we sold up. Then there is the 'eco' bit to think about.

Not just the length of time, it is the power of each heating source. If your kettle is about 2.8 kW and your gas boiler is 20 kW, then 5 minutes for the kettle is 0.23 kWh, boiler 5 kWh. So get some proper timings, the power ratings and we can see. And outputs. What size is your battery system and what is the utilisation like? Finding the Goldilocks zone is the hard part. There are 3 parts to having a battery system (4 if you include cost). The actual usable storage, the kWh. The charge rate, the input kW. The discharge rate, the output kW. It is this last one that is important as some system need a 200W+ load to start delivering and may top out at a 2 kW load, though I would hope most would be capable of 3 kW at least (enough for a kettle).

Polyurethanes can shrink quite a bit. We used to work on 3 to 5% depending on the mix. Some of the fast setting elastomers can easily be 10% and continue to shrink for years (Look at a Panther Kalister dashboard, it was a perfect fit when I made the tooling). Think how plump your new furniture was compared to when it is a few years old. I have heard that you can buy 'aged' insulation, but not really convinced it is of any benefit. As for the picture, that looks like something went wrong in the manufacturing and storage. Probably it got wet somewhere along the line as it is warped and shrunk (warping is actually caused by shrinkage, think bimetalic strip). It is not a unique problem to just polyurethane, really a problem for all composite materials.

There seems to be some confusion about my comment on storing energy as hot water. It was never meant to mean store all your energy as hot water. That would be a bit silly. It is also silly to heat and store more water than you actually need. So while the volume of a cylinder may be fixed i.e. 200, 220, 250, 300 litres, the mean stored temperature and be varied, within limits i.e. not too hot, not too cold. There is, as @pocster and @ProDave illustrate with their set ups, a zealous need to export nothing and overstore. That is a bit silly as well. When the original question was asked by @DazRave, apart from spending £10k on a system, which says nothing about the size of the system, I was also unaware that he had gas already. But let us look at the cost of gas. I don't have it, but there is a standing charge, is that similar to electricity i.e. 60p/day? How much is an annual service £150? Assuming a combi boiler, how efficient are they when heating water for a few minutes shower, 80 to 85%? Never seen anyone work that one out. There is also the added benefit that roof integrated PV can decrease solar energy entering a loft/roof void by about 18 to 20%. This may help, depending on house design, reduce the need for summertime cooling. Cooling should not really be necessary though, it is a building design failure.

Hard to wash in a TV. Now stop being a twat.

I don't see why not. Not really infinite depth, semi infinite. So long since I had to do this sort of thing that I would have to do a lot of research. My simple method of expanding the slab size, by the slab thickness will be close enough.

With a bit of Fourier thrown in I seem to remember. I once, over at the other place, model the heat flow in two dimensions though a solid, seem to remember that it is just a cone made with exponential curved sides. That is the losses for a cylinder, but should not be hard to chop it into a rectangle and take away the 'off cuts'.

You can get 'diverters' that sense when the system is exporting power to the grid and turn on the water heater, or battery charger. The thing to remember is that PV is not a constant power, or even a normally distributed power curve. It is very variable. If you can find a local WeatherUnderground station that has a solar meter on it, you will see how, even on a sunny day, there is often a lot of variation. Two very very rare days in a row. 3-6-23 4-6-23 5-6-23 6-6-23

What is hard to put a price on is the satisfaction that you are are generation clean energy at source. You can make a game out of planning when the washing is going to be done, and for a lot of the year your hot water will be solar heated. Storing the PV energy in a cylinder as hot water is the cheapest type of storage, way cheaper than batteries.

What has the increase actually been each year, 1%, 0.5%. Data is needed to back that up. I have to agree, and have no idea what the answer is. They died of hyperthermia back then as well.