Nickfromwales

I believe the ones that run down to the sub zero temps have an integral electric blanket to keep the cells from getting that cold. Needs more reading tbh, as some descriptions are void of comprehensive details. The batteries own BMS probably takes the first chunk of charge to warm the cells, before allow the cells to recharge. Just picked up most of these scraps of info by scouring the net and some off-griddy forums. Plenty of gold out there, and here, just got to stop digging at some stage and plug this lot in.

Yup. Very few don't have some flat spots / standing water.

Can you show exactly where the sliding doors are going? If the'y're going in the room currently called 'lean-to', then as a thoroughfare to outdoors it's becoming a less convoluted route to get from playroom to outdoors? TBH, it would be the same if they were going into the rear wall ( top of the drawing )? You're not adding a maze of corridors! As it stands, you need to get through 4 doors to get to outside / rear from the current playroom? Can you get a second opinion? Offer to install linked ( mains ) heat / smoke detectors in those rooms for early warning?

https://www.ebay.co.uk/sch/i.html?_ssn=debattery-66&store_name=kepbattery&_dmd=2&_oac=1&_trksid=p2047675.m3561.l2562#item2416985d05 Cheaper than Eco-worthy? Free shipping, so seems a better option. £365 ( total in Ebay checkout all in ) vs £482 ( including 'estimated taxes' at EW checkout ) at a quick glance. Both have internal BMS. Those 24v / 100Ah batteries come in @£748 per, so circa £1500 for 4.8kWh / £3k for 9.6kWh, so, if they are looked after and last 8 or more years I'm sure I will stay in the black. I'd be happy to break even tbh, if it means not buying from the grid. If your inverter is already your BMS ( hybrid ) then I like those prices! Buyer says "best offer" too, so may try a cheeky lower bid and see what they will drop by. Considering qty 2 of the 24v offerings for the get-go ( installed in series to get me to 48v for the Iconica ) and then possibly add more when I increase the size of the array, but tbh I will probably up my direct ( self ) consumption instead of adding more batteries as that's got longer legs / better economics. I very likely won't do anything more after the initial install eg until I have 4 seasons of statistical data tbh to reflect on. The plan is to oversize the PV regardless, to then have enough residual for the winter to chew into space heating costs, as I am going to fit A2A to get AC in the summer ( defo happening ). That can be used to heat the home too, or at least do a lot of the constant background heating vs heavy lifting ( where the existing gas CH will kick in to give things a nudge when it gets baltic ) plus a view to using gas at night ( if so required ) for quiet operation when sleeping. Over-all's will improve slightly with some downstream fabric upgrades, and the gas system will go ( be evicted ) eventually I expect, but I'm working on a decade long proposal atm as I will probably build something new / efficient after that and just migrate the panels with me ( 25 year warrantied - 30+ year expected lifespan on those ). Buyers perspectives will be much different by then I expect, so we will see if I leave the kit behind or not.

Charging 'in' the cold Eg minimum working criteria / tolerances dictating where they reside.

Yup. EPDM seems to wrinkle up a lot, and doesn't look good when it does imho. Long linear wrinkles holding water when at its worst. GRP is stable, concrete solid, and has great longevity. Colours can be manipulated by simply choosing different top-coats. Needs to be done properly, and not by someone who is skimping on the product eg leaving you with a wafer thin end product. Ask questions, and get answers in writing.

Batteries will be in the man-shed / office with A2A space heating set to minimum of 15oC so no issue for me with temps, so looking like a better option than AGM atm.

A bit more M2 of roof space for the same wattage of other 'on-grid' panels, but 6 and two 3's if you have the space to fit them? It says completely off-grid, so you'd need to research the inverter to see if it will accept a generator ( or grid AC ) feed as well as the panels and batteries. If not, it wouldn't be suitable for retrospective integration into an existing on-grid setup like yours afaik. The Iconica 11,000W hybrid I'm trying to source atm is one such device, eg which is capable of fitting into either camp ( on / off grid ), but, as I am not familiar with that offering linked above, I cannot say yay or nay for you. Would not be cost effective if you cannot simply plug the lot straight into your CU. The Iconica gives UPS out of the box also, with near zero switchover time, so in a power cut you'll stay lit and burning with just a 'blink'. You get a complete system, high capacity / spec, for the price most are just buying the batteries at ( size for size ). I have my 24 panels, all Tigo'd ), just the inverter to source and then it's "f**k you grid!". I do like the price / stats of the LiFePO4 batteries, and am looking on Alibaba etc to see what's about atm. Batteries are the one thing I'm currently deciding, with choices - panels ( procured ), optimisers ( procured ), and inverter ( waiting on new stock to arrive ) - now cemented.

In terms of sign off, the GSR chap will look for 18.5mbar or above ( check the MIs of the appliance you select ) and that’s with the hot water tap fully open and the boiler going at 100% burner rate. The supply from the street is fine for a bigger meter, that’s all you’d need tbh. Combi kW ratings have zilch to do with heating, as that usually takes <12kW even in a poor dwelling, and specifically relates to the devices capability to produce DHW.

Yup. With today’s water bylaws, most taps / other outlets are flow governed by manufacture, so a 22mm feed is pointless. Also, unless this is a monster heat store combi, the cold inlet will be 15mm, so another reason to not employ 22mm hot pipework

You do not want to upsize the hot water pipe. You’ll massively increase the delay in getting hot water out of basin / sink taps. 👎

FWIW, I’m on a TF house atm, with 300mm glulams and I got permission for pre determined / agreed location etc 96mm holes. Can be up to a 1/3 of the depth dependant on thickness of wood.

Structural engineers can help you decide where to drill that number of holes. You should be fine, don’t go to the expense and ugliness of boxing in etc 👎. You can stop the insulation ( if it’s actually required ) either side of the joist to make the holes smaller. What is the 22mm feeding? Not hot water?

+1

I doubt they’re massive tbh, so I’d stop worrying about that and look at practicality. Go with the garage, as when converted to AC all you “need” to do is upsize the cable to combat any losses vs distance. Say upgrade from a 4mm2 cable to a 6mm2 cable for eg. Done jobs where we’ve run the AC for 135m ( ground mounted PV with external inverter ) and was still performing extremely well as we upsized the SWA back to the CU. I think you’re over thinking a little. It’s all within the footprint of a single domestic dwelling so afaic you can relax a little and just apply a little sensible mitigation to get the best result from a practical installation

OK, firstly.... 350mm of XPS? Secondly.... Which ICF system is this? Woodcrete / EPS ?

Space a plenty, speak on Obi Wan........

That’s what I’ve been thinking for some time….. Header tank is way too small, so when low the splashing water from the fill valve stirs up the sediment. Extra Radox is recommended lol.

Heat circuit input connections to the cylinder just look too close together…….

I’ll need a pint in my hand before replying to this later. In the interim, is there 100% defo just the one header tank servicing the copper cylinder and Rayburn? Looks like it from the images, which send a shiver down the spine…….

There will be plenty of large car and HGV batteries around for the next 10 years at least. I’ll worry about that again after the first 10 years has expired. Not lithium no. Regular car batteries. Cheap and plentiful in the used market.

If going for the Tesla tariff then export is defo required That’s why they give you this “deal” isn’t it? So they can suck ‘em dry as quick as you can fill ‘em. 50% of 48kWh is still a bloody decent bit of storage for a domestic setting. Most decent size dwellings where we’ve installed PV plus batteries have had a 9.6kWh and that’s often difficult to routinely fill and empty ( by themselves ) every 24 hours. With the multiple hybrid(s) you also get the benefit of huge rates of discharge, plus instantaneous UPS to boot. Would piss me off to be having peaks of consumption that called for support from the grid, when there’s perfectly good stored energy in the batts. Cheap as chips for the sizing, zero export capable out of the box, so what’s there not to like? Yes, you’ll need a bit of room to fit the batteries, which to most will look “unsightly”, but I think my electricity bill is unsightly, so my minds made up. “Death to grid dependency”.

I thought it was only me that only opened their mouth to change feet 🤣

In a nutshell, yes, so minimising the capital cost is of paramount importance if you want to even glance at breakeven / RoI numbers Folk need to remember that charging off excess and then using it of an evening is a relatively easy life for a battery system. Change the scenario to where you sign up for the Tesla / Octopus arrangement and your batter is in for a kicking, thus further reducing its useful lifespan ( can drop to 7 years of 'usefulness' vs 10 with the right amount of abuse. I'd be interested to hear what the warranty wording is like for that system in that arrangement, as they benefit from beating the shite out of the system you paid for.........and then own.........and have to maintain / repair / replace....... @Wil I'm waiting to get a reply from a supplier for an Iconica hybrid inverter ( 11kW ) which is sub £1500, and then I can open my horizons to which battery I choose to employ ( within the manufacturers recommended connectable equipment options of course ) but I am also looking at BMS options to charge near end-of-life commercial vehicle batteries. Cheap option, with fleas that come with the dog ( monitoring / replacement etc ) but the costs should be vastly cheaper. All depends if you want a nice looking shiny box that someone fits for you, or if you want to ( and are able to ) get your hands dirty with a bit more of a bespoke setup. Pointless doing anything unless its really worth doing tbh. Change of £9k before VAT........ https://www.photonicuniverse.com/en/catalog/full/566-20kW-Zero-Transfer-Uninterrupted-Power-Supply-UPS-System-with-48kWh-energy-storage.html

I've seen a YT video with some Tesla do-dah that connects to your CU after 5 seconds of grid 'absence'. Not sure what it was called, but Robert Llewelyn has one in his garage. "Fully Charged" was the channel.