• Following, I have nothing useful to contribute but look forward to watching this progress.

  • @Cazakstan @greentricky @si_mon628
    Thank you, keeping everything very tightly crossed for it!

  • Updates:

    Digger is going to be out starting the groundworks on Friday which is very exciting, been looking at an empty field from the place we’re renting going on two years now..

    Got our wastewater treatment plant delivered. A biorock ecorock which has no electric pumps or components to reduce drain on the system. Supposedly drinking water will come out the other end but unsure whether I’ll be testing that. Even though there’s only two of us we had to buy a system big enough for 5 then they were out of stock of that so sent us one to do 8 people for the same price. Pretty good but will mean higher costs for digging a bigger hole.

    @jono84 never mind the steamroller with a 55t I forgot about the 57 on my rossin 😂

    @Velocio sorry, should I have put this on the non bike current projects thread? Is there a way to transfer to there without losing anyone who’s subbed to follow along?

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  • Moved and subs preserved.

  • Much appreciated, thank you!

  • Digger showed up today! Think today will just be stripping back grass and topsoil over the build plot to keep for future landscaping projects

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  • Absolutely awesome project, in theory it's similar to what me and the wife are trying to achieve in Portugal...

    What materials are you building the walls with, straw bales?

    Subbed and looking forwards to following all the updates>

  • Thank you sir, how far along in your project are you? Timber frame with a mix of wood cladding, cement board cladding with a silicone render and masonry work around the porch.

    Got my own wee groundworks project going today too. Expecting an 8x10ft polytunnel to arrive soon so cleared and levelled some space for it, popped a wee drainage channel around it and ran it to the drainage for the planticru and extended that a bit.

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  • Sounds like an excellent mix of materials! Like the sound of the silicone render.. Personally I like the Straw bales, as they offer fantastic insulation, whilst being eco and sustainable etc...

    We were planning on buying a plot 2 years ago, but the whole CV fiasco, has marooned us in London..

    Fortunately the wife is an architect, and her native tongue is Portuguese, so it's a bit easier for us, than the average escapee's from Little Britain

  • Presumably there's an additional layer of admin here @Creek_Tebsin, as you have to get plant & supplies etc over on a ferry? Or a helicopter, please say you get stuff Chinooked in...

  • It's Orkney.. It's not that remote!

  • Hello Tebsin, Amazing spot you've chosen and your drawings look quite well done.
    Not sure how far you've gotten with power management but this seems similar to a camper van or small yacht power management scheme. Those systems typically rely on battery storage.
    The chain is: Power-gen (DC) => Charge Management Unit => Batteries => Inverter (AC) => Load
    Charge Management Unit controls when charging occurs (low battery level) and when a battery is allowed to supply power to the system load (Full charged to Min Charge). All of these components are commercially available so the task is to scale the components to your application and install to code.


  • Yeah, really good and really cheap, but between how consistently damp the air is up here and how strict planning are. Read about ash being an incredibly good insulator and soundproofer behind walls as well.

    Sorry to hear that and hope you get back on the move with it soon!

    @si_mon628 fortunately for the bank balance there’s no helicopters involved but we are on one of the small islands off the Orkney mainland but we have a ferry that can take trucks and things.

    @hurricane_run haha, don’t tell him that!

    @Video-Sid cheers, I might have to pick your brains a wee bit. We have projected load curves and things if you want a look at them? With how expensive the batteries are, are we best to have them after drain purely to try and reduce number of cycles? Quite new to the storage and how it plays into the overall system..

    Here is how the ground was looking this morning and we’re getting a groundsheet and stone down before starting digging the founds. Fortunately a farmer had a bunch of stone from taking a building down so this didn’t have to be ferried across which probably saved a fortune!

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  • Good point regrading battery charge cycles. Depending on how the Charge Management Unit operates, it should provide power directly to the load to minimize the number of charge cycles to the battery. If you have enough output from wind gen, you might not even need to use battery power. In that case batteries would be a nice backup power source. Have you specked wind gen unit yet? I have no experience with them but I know a guy...
    This is what our solar array produces for a typical early summer day. I don't know what our consumption is but we are typically producing more than we need.
    If you have load curves, post them up.

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  • We’re hoping between the wind and solar panels we should only be finding ourselves struggling or relying on the storage if we find ourselves with a few Misty windless days in a row. Here’s some of our load demand data here but will pm you a more detailed one with projected generation as well we’ve put together (although using old figures as we’ve scaled up the turbine since we did these and really need to sit down with them again.)

    Think it’s going to be a kingspan kW6 turbine and between 4 and 4.5kw of pv panels can fit on the south facing workshop roof.

    We’ve been looking at a victron Quattro 15kva microgrid and inverter for in front of the storage system and around 20kW of BYD lithium batteries in a scaleable storage system.

    Working from home at my fuel poverty charity job but getting very distracted seeing the digger show up again today..

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  • @Video-Sid found this too

    My partner has worked in renewables for a while so took charge of this bit while I focussed on getting the actual build together but she’s only worked on large scale things before rather than a small system like this so is unsure how all the bits will interact

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  • Did you consider a large solarPV chemical battery? We removed our thermal store (to avoid standing losses) and instead treated DHW as part of our excess PV usage. We have a SunAmp Uniq and have been very impressed with it! There are lots of good threads on the BuildHub forum if you fancy getting into the data.

  • What are the u values of the house?

    How are you ventilating the building?

  • Thanks very much and will give it a closer look. We had looked at the sunamp before but I think why we decided against it was mainly due to times of really low production (ie still and cloudy or misty days in a row) where we wanted any saved energy to be in electrical form rather than heat in case we were switching heating and dhw off so we could use lights and keep freezer going etc. Probably deserves more of a proper going through though. So hard because each installer we speak to is knowledgeable about their parts but not the whole system..

    @M_A_X U values we’ve been given are 0.10 for the roof
    0.16 for the vaulted ceiling area in the centre
    0.17 for walls and
    0.12 for the concrete slab floor.
    Building control have passed it with the number of opening windows we have alongside a DMEV in the bathroom and a DMEV and cooker hood extractor in kitchen area.

  • We get surprisingly good power even on cloudy days, or in Winter. At least 25% efficiency on our measly 4kW of panels. Although we do have the option to top-up the sunamp unit overnight on an economy tariff too.

    You could use a manual/dynamic switch to always charge your batteries to [x]% first and then start working on the DHW? Typically, the sunAmp unit will be more efficient than your grid (and will last ~40k cycles, or ~50 years).

  • This is really interesting, thank you! Didn’t realise there would be the option for a dynamic switch like that and just kind of wrote off the sunamp as was focussed on retention and storage of “power” rather than heat. Did you spec the system yourself or is there a company you’d recommend we talk to?

  • A bit of a mix of an enthusiastic plumber (relative), a PassiveHaus consultant and the SunAmp crew themselves. I found the BuildHub forum to be excellent, lots of people will gladly talk you through their own setup. We didn't have space heating, so our setup was pretty basic.

  • Sorry for the delay in response, hectic just now.. thanks very much for this and will have to spend some time on there soon.
    Builder is also working on something else on island (a shed for some e-bikes for the island trust) so haven’t been on site in a few days. My friend from work flew over this morning and got this shot, can actually see the outline of where the house and workshop will sit now.

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  • Recent photos have provided inadequate quantities of dog. Please rectify.

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Off grid house build orkney - looking for help with system spec

Posted by Avatar for Creek_Tebsin @Creek_Tebsin