Crofter

So why isn't the industry making this case? The figures were seen in this thread area from the industry, and are likely on the optimistic side.

I'll bow to your superior knowledge on this, I was just going from what I could find as a lay person when googling the question. Numbers vary a bit but I'm getting estimates from 450-670m barrels between Rosebank and Cambo. So that's less than a decade at the consumption figure you've given above.

Analysis without numbers is merely opinion. The West of Shetland oil and gas won't keep the lights on for very long. Less than a decade if we extract everything. And some of this is likely to be uneconomic due to conditions.

1kwh is tiny, I'd imagine it would be much better value to fit larger batteries than that.

I never knew that. It does make sense though. A 4" SVP can adequately vent a pretty large building. I have a 2" SVP on my little place, so that I could hide it behind the cladding. It works perfectly. I can only do this because I didn't have to comply with building regs.

Wow. I knew it was expensive but I didn't realise it was quite that much!! Not sure about current prices but the guttering on the little house I built was under £200 all in. Been up about eight years and still looks brand new. So I think that after 50yrs I'll be coming out ahead on cost. I just wondered if I was missing something.

I've always wondered, what's the advantage of metal guttering? It's a huge price premium over plastic which, in my experience, works perfectly well. Is it mostly an aesthetic thing?

Would this be a good point to trot out this perennially relevant cartoon?

This is a little misleading, because China of course are manufacturing the whole world's goods. And there is more manufacturing being done in general.

I used to think that battery storage couldn't possibly play a meaningful part in supporting the grid. I'm starting to change my mind. I'm not saying it's necessarily the best way forward, but with LFP tumbling in price (no Co in these) and Sodium entering the market, the price for battery storage is far lower than anybody predicted even a few years ago. Add to that the proliferation of EVs, with lots of battery packs ready to go on to static storage once the vehicles have rotted away. And of course V2G should be part of the solution. By my back of envelope calculations, an average EV should be able to run a house for about two days straight. That might not get us through every period of calm, dim weather, but it will go a very very long way. We'll probably still need some gas generation to plug the gaps, but I genuinely think it will be possible to get to 10% or less fossil fuel dependency on the grid.

In a few years time I think we'll have stopped worrying about EV range. It makes far more sense to transmit energy down power lines than to drive it around in a battery. Better charging infrastructure will allow smaller batteries, lighter cars, more miles per kWh.

I hope I'm understanding you correctly, but are you saying that you're worried that a layer of ply underneath the kingspan would rot? I'd have thought it would stay pretty dry, it't got an entire hut on top of it. If it helps at all, the little place I little place I built has a floor build up of (from bottom to top): 9mm OSB, 300mm glass wool, 22mm moisture resistant chipboard (glued and screwed), bamboo flooring bonded down. This is completely exposed underneath as the building sits on piers. I'm in NW Scotland and we get our fair share of driving rain here. The underneath of the building remains perfectly dry. It's been up nearly ten years now and it looks the same as it did on day one. Glass wool is obviously going to be a bit more permeable than PIR, but I imagine you'll be fine. And OSB could be slightly more permeable than ply. Maybe.

I used loads of this stuff during the build, and I'm going to need some again soon. Neither Screwfix nor Toolstation seem to stock it any more. Checked B&Q and no joy there either. AFAIK the stuff can't be posted (even though ordinary expanding foam can). Any suggestions for where I can get some?

That might be more plausible were it not around 2⁰C just now.

Finding a rainy day to do the job shouldn't be a problem!

Just bumping this topic because it's time for me to do a bit of maintenance work on my tar planings driveway. Question- should I sweep any loose stuff away first? Seems like it might be a good idea to get the best chance of the new batch staying where I want it. I could probably part fill some of the deeper holes with the loose stuff, so long as I leave space for a couple of inches of fresh stuff on top. I'm just going to be getting a trailerful (about half a tonne) at a time so it's really just a patching job. But I think I'll hire a whacker to go over the whole thing. Anybody got experience of repairing holes in a tar planings surface? It's funny stuff... not exactly loose like aggregate, but not exactly solid like real tar.

I was amazed how long it took me to roller my place. 43m², vaulted ceiling. Not exactly a huge project. But the fresh plaster just drank up paint. Worst bit of all was the cement fibre board behind the stove. It seemed to take dozens of coats before that wall looked uniform

It's not a hard run- just across some rough ground at the back of the garden. I'm not digging up a driveway, or even a lawn. So I don't think I'll regret it too much if I do end up having to re-do it. Anyway... cabling aside, with the rest of the installation, what would be best practise: - breaker and/or isolator up at the panels? - breaker between the Eddi and the immersion? - anything else that might not be obvious to me?

I appreciate that, I just thought maybe I was missing something. I'm not sure how likely an upgrade would be. I'll be maxing out my permitted development with this ground mount array, and the next sensible move would be adding something to the roof. I also have the other property which would benefit from a similar setup, and I'd likely do that project before I did any upgrades to this system. I hadn't heard that standard SWA wasn't suitable for DC. I thought that so long as you stayed within the voltage rating you'd be good. Would something like this be suitable? https://www.superlecdirect.com/6942x-6mm-2core-bs5467-xlpe-swa-pvc-cable-harmonised-black/ (the datasheet for the above cable shows DC and AC values. The 6mm2 is rated to 53A when buried in the ground, which is a lot of headroom for a system that should be generating around 15A)

That makes sense, thanks. I'm still wondering why the DC cables need to be so beefy. I did my initial calculations based on twelve 285w panels. That gives a minimum system voltage of 348v, and a maximum current of about 10A. Even a skinny little 1.5mm2 cable will only show a voltage drop of 1.82% over 25m. Upgrading to 4mm2 gets me down to 0.6%, and 6mm2 would be 0.45%. I just didn't think that was necessary? I could use a smaller number of larger panels, e.g. seven, giving me 234v/16A (gives a slightly smaller array overall). In this case 1.5mm2 is definitely too small (more than a 4% drop) but 2.5mm2 looks pretty good to me (2.6% drop). 4mm2 gives 1.6% drop. 6mm2 gives me a 1% drop. I've built a lot of off grid stuff where this kind of voltage drop is of no concern. but I appreciate that things are a bit different. When you have a panel pumping out 17v and you want 14v to charge a battery, you can afford to lose a whole volt somewhere and it will still work. I'll happily stump up for the chunkier cable, I just like to know why...

Thanks everyone. I'd initially read/heard that the long run should be before the inverter. Then somebody (on Faceache) said it was the other way round. Does the choice of panels affect this decision? E.g. if I had ten 300w panels, I'd be running about 300v DC or more. But if I had seven 500w panels instead, I'd have a lower voltage. You'd think you'd want the longest run to be where you run the highest voltage, for lowest losses and smaller cable sizes. Bear in mind I'm coming to this with fairly extensive off-grid experience so I have a certain amount of intuition which isn't necessarily helpful

So I've been told that it's best to place the inverter up at the array. I think I'll need to make some sort of enclosure for it due to the weather we get! I'm also a bit confused about cable sizes. By my understanding, if I have say ten panels in series, I'll have 300v minimum. For a 3kw array, that means about 10A. So I should be OK with a 1.5mm2 cable over my 25m run. But everything I read says I must use 4mm2 minimum. Am I fundamentally misunderstanding something here?

Are they honestly going around the country sticking in replacement meters and then walking away leaving the homeowner to pick up the tab for the re-wiring? The way this house was set up until recently, the panels heaters were the only form of heating in the bedrooms. So disconnecting those would not have been popular. I've had the A2A installed and those heaters are now defunct, but that was my choice. Will do... when the rain stops!

We have two CUs, the one on the left is the THTC one which is split in to two. I've just had it confirmed by OVO that we will get a single smart meter to replace the dual meters we currently have. I'd have thought that, to change to a single rate tariff, all they have to do is bill me at the same rate for everything. No re-wiring required. And just to complicate things, I want to add a diverter in to all of this. Hmmm.