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Cars are designed for a global market. 3-phase is common in commercial charging points and homes in Europe. Most cars will charge faster when plugged into 3-phase. Why they have cheaped out and only put chargers on 2-phases I'm not sure. Guess it's cost saving rather than targetting a specific market. 2-phase supplies are common in some places (notable the US - though 2-phase US can be used as single phase 240v). Depending on how they wired this up internally, you may be able to supply the same phase to both internal chargers, effectively running 6.4kw single phase. IIRC a lot of modern 3 phase kit, is 3 seperate single phase supplies rather than something that requires the phase separated phases specifically.

Octopus offer the 15p export price but AFAIK they have a limit of 15kW of solar, so not sure they will offer that price to you if you go over that. That might make a 15kw export array more profitable than a 30kw one. Not sure about other providers and their pricing. Even if you do get the price then don't bank on it being around for the life of the array so don't base financial decisions on it. Agree that a large hot water tank isn't worth much given the amount of electricity you plan to generate. If you do a lot of miles via EV then being able to use the solar for that would be a big win, but then you have to wonder if the cars will be at home plugged in when the sun is up. If you get the 15p export rate an can export as much as you want it's no big deal as you can export at 15p and import overnight at 7p. But if you are export limited then batteries would help you time shift, but that is going to be very expensive and it probably doesn't make financial or environmental sense (to have sufficient batteries to charge cars). Your roof angles are also not particularly well optimised for winter generation, where excess panels can be really helpful. PVGIS is showing you that in winter you don't generate much. It may be worth considering if there is a location on your property that is not the roof that might better suit at least some of the panels. If you can angle at 45/50o you could generate a lot more in winter, which would likely be more useful long term (especially if export pricing during summer months becomes less attractive).

Wondering if you can unlevel it in a way to bring the insides straight? Would have though it would be relatively easy to push the frame 10mm in one direction or another over a distance of metres. Failing that, probably isn't the end of the world to remove the french doors and refit if it came to it. (either the seller arranging that or DIY) If the caravan isn't a leaky mess and all plumbing/electricals work then you have a good base for a while. No practical experience with these things but my impression from reading here is that buying second hand you will always have something to deal with with these units.

Steve Baker is making an impression I see.

I'm going to try and put my thoughts down here. The physics of enthalpy is a bit much for me so this is just how I understand it. But my understanding was that enthalpy is not a bad way of talking about what these things are doing. Air with 0% humidity at 30oC is in a much lower energy state than air with 100% humidity at 30oC. If you live in a hot climate with high humidity. Say Missisippi, then you really want to have an ERV vs HRV because the incoming air will be saturated with moisture even after the heat has been exchanged, which you will then need to use AC/dehumidifier to extract. In many parts of the world the dehumidification demands more power than cooling, so these ERVs are doing what they say they are. In this country where we don't generally have a lot of high humidity high temperature days and we also don't tend to air condition our homes then ERVs are not as useful. They will provide some benefit, possibly by preventing moisture leaving the house during cold winters*, but at least to my understanding, it was generally considered unnecessary to spend the extra for an ERV vs HRV in this country. As to your other questions, I'll leave that to others as I don't have the personal experience of one. * Thinking aloud but this may be seen as a negative in some homes with no other way of dehumidification, as you are trading the extract of humid air with dry air most of the year (which we often want) with preventing the air getting very dry in very cold conditions.

The 48V approach? I thought @MortarThePoint was making a more theoretical argument. Not sure there is much 48V lighting available to buy. Voltage doesn't really relate to brightness. All white LEDs need about 3.3V. The difference between a bulb needing 12v 24v and 240v is the number of LEDs run in series vs number in parallel. Brightness is just dependent on the specific layout within the bulb/strip. Bulbs/strips are sold on the basis of a brightness output often in lumen. The only case where voltage matters, is if you have undersized your supply cables which is to be avoided in all cases (even if you don't care about efficiency) because an undersized cable will heat up.

Now updated my knowledge: https://www.sigenergy.com/en/support/files/2213 It's still reduced functionality 'for your safety'. Struggling to find the reasons for most of the restrictions, most of the justifications I can think of are to limit warranty claims for more extreme cases. Edit to add: other systems don't have such artificial limitations. They claim they may add more functionality in future, but equally they could take stuff away in future if you are limited in what you can do without their involvement.

A big negative with them as far as I'm concerned is that they explicitly tell you that if their system can't call-home via the internet it may disable function after a period of time (30 or 90 days). That's unacceptable to me under any circumstance for something you expect to last 10+ years. Who knows if they will still be around then and if not you have a very expensive and heavy paperweight. Cloud connection should be for additional quality of life features. Basic function should always be there and locally manageable.

That is just a point to point antenna for wifi. I agree that you likely need a directional antenna each end for a good link over 100m but 100m isn't that far in the scheme of things. People are running wifi links measured in kilometers at decent speed. Psst: wifi signals are microwave signals 😛

Microtik is the other name I was thinking of, not necessarily for the non-technical. https://mikrotik.com/products You can do this on a lot of home routers too but its not necessarily well documented. OpenWRT supports doing it if your hardware does so a router that can have that installed is an option. But if you have 100m to traverse you should be looking at specific point to point antennas which pushes you towards the ubituiti/microtik type options.

Oh in that case the Ubiquiti suggestion is a good one. Building to building links is one of their business focuses. A number of other companies in the space too but the names escape me right now.

And lower generation per m2 and somewhat unknown/poor reputation for longevity.

Have you got a multimeter that can detect the PWM signal on the output? Would be good to be able to know whether its a problem with the unit sending the signal or the pump recieving.

As you know from previous threads I see the appeal of a floated floor for certain properties, at least as a phase 1 cost saving measure. But as soon as you add the complexities of not having a single level slab with no corners to negotiate I think you can throw any idea of cost savings out of the window and instead you are looking at a concrete floor as a premium option not a cost saver. If so, then there are other ways to go. If you are thinking of it as a cost saving approach then I think you need to change your plans. Either its dead simple and easy for the contractors or it's not happening. In other words I think it's only a viable option if you have an insulated slab or have designed around an uninsulated/badly thermally bridged floor (which I'm not sure would meet current regs).

That's what I guessed. Means it wouldn't work for @flanagaj if he wanted to powerfloat the slab, not put insulation and another concrete layer on top.

Is this to create one big network? Sounds like it. If so, the modern way to do this is with Wifi Meshing and it's supported by many many devices. Best to use them all of the same brand though to avoid any issues. You can often get them in multiples bundled together. Not recommending anything in particular but: https://www.currys.co.uk/computing/networking/whole-home-wi-fi-systems

How did you handle floor insulation?

I did a bit of digging trying to remember who this was. Theres a company called Polish Interiors that does windows but it's definitely not them, their range isn't even close. I came across fenbro.com which seems familar and is Polish. Looking at their site some of their windows look very much like the one I saw and liked but can't say for sure it's the same, and they seem like a reseller anyway so I guess maybe it was another reseller selling the same product? https://fenbro.com/products/aluminium-window-mb-104-passive-si/

It was more than a year ago now and my memory is hazy as it was more a scoping trip rather than a detailled specific look with note taking (went to the Homebuilding and Renovating Show at Excel in London on a whim as it was nearby). I know I wasn't particularly impressed with Internorm and Rationel. One that did seem to tick boxes was something like Polish Windows but not sure the name. They were really flogging the sound reduction properties of their windows (though I guess that is the same for any good triple glazed unit) but they felt right to the touch/look to me. The Internorm/Rationel ones either felt a bit clunky, had wierd locking mechanisms/handles, had fake plasticy wood film frames or engineered wood which in theory I don't mind but didn't seem well done. A lot of these things are options so maybe theres a good combination that I missed/wasn't displayed but for all the talk on here and elsewhere about how premium those brands feel, I couldn't help walking away thinking that I wouldn't want to pay a premium for anything I saw at their stands. I guess I'm picky.

Indeed, I found I wasn't that keen on some big brands that people use here that I expected to like. There were some nice elements but the overall packages seemed flawed in one way or another. Ended up liking others that I'd never heard of before. All a bit to early for me though (when I went I thought I'd be in a position to move sooner rather than later but that now seems to be significantly delayed).

Here is a Fronius doc exploring this though only by a small oversize. I've seen others discussing much larger ones but not got time to search for them. https://www.fronius.com/~/downloads/Solar Energy/Whitepaper/SE_WP_Yield_Impact_Current_Oversizing_EN.pdf I note the comment at the end about short circuit current limits. That one does have to be complied with but it is much higher than the MPPT string limit.

That was not my understanding. My understanding was that you could go over the amp rating by the allowed amount for the inverter. The inverter will limit the amps it draws from the panels to the amount in the specifications, but the panels being capable of outputting more is not an issue (within a limit). The inverter can manage this through adjusting the MPPT point.

Overpanelling by up to 50% is common and helps generate more electricity in winter but imposes a cap on generation in summer. Inverters do have ratings for the extent of overpanelling they support though. I think 50% is common but 100% options are available. Given the amount of sun we get in the cooler months and the price of panels it makes sense to overpanel as much as possible if you have the space.

Don't just stick normal strips underneath, you need a diffuser to avoid seeing the individual LEDs. You can get COB strips that have diffusion built in but the are usually white only so may not be what you want. So get an aluminium profile with a diffuser strip if you want a good looking outcome, consider getting profiles that angle the light in the way you want. I'd guess there are some prepackaged solutions for significant money that might avoid the profile but then you have lock in to the manufacturer rather than a generic, future proof, solution.

Saw rivets mentioned as the preferred option with screws the more standard one.