Green Building Forum - Offgrid - how much will it cost? Tue, 19 Dec 2023 05:16:12 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12763#Comment_12763 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12763#Comment_12763 Fri, 18 Jan 2008 10:13:16 +0000 StuartB
What renewable technology would you use to provide all your heating and power needs for a 4 bed house? If it can't be done for less than £15k how much do you think it would cost?]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12768#Comment_12768 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12768#Comment_12768 Fri, 18 Jan 2008 11:54:15 +0000 stephendv http://www.casanogaldelasbrujas.com/blog/?p=9
Double check those values though, as I'm new at this!

I calculated that for my wife and I in a 2 bed house, we'd use about 6.7kWh per day using new energy efficient appliances and CFLs. No skimping on electricity either as I've included running a bunch of electronics 24/7 and powering a MVHR. The PV panels are designed to supply electricity March through to October and we'll be relying on some help from the generator in the winter months. It's just not economical to size the array for the whole year. Estimated about 24k Euro for the complete setup.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12771#Comment_12771 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12771#Comment_12771 Fri, 18 Jan 2008 12:10:17 +0000 tony
we cant say yes or no without a lot more info.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12787#Comment_12787 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12787#Comment_12787 Fri, 18 Jan 2008 16:52:59 +0000 howdytom tom]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12789#Comment_12789 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12789#Comment_12789 Fri, 18 Jan 2008 18:31:49 +0000 GBP-Keith
To be truly off grid for energy, you will need to spend £25,000 if you self install or £35,000 + if you use installers. You will need a tri or quad-hybrid mix or massive batteries. Tri-hybrid would be wood, wind and solar (active, passive and PV). Quad-hybrid would include some water power input.

Lots of hands-on too. If you are in a really windy site than a large wind turbine 6 or 15kw will give you a good proportion of your annual power but not complete.

Frighteningly rough breakdown.
Wood boiler and system - £7,000 self install or £12,000 installed

Inverter, batteries etc for electricity - £4,500 self or £6,500 installed

Wind turbine - 2.5kw £16,000 self install may not be an option

Micro water turbine if water available (include for pipes, ponds and lots of wasted time playing with water) - £4,000 self install or thousands and thousands if installed

Solar PV - how deep are your pockets? best technology though so budget as much as poss - say £5,000

Solar thermal - £2,500 self install or £4,500 installed

Solar passive can go into your design at little extra cost.

Dont forget the logging equipment and the land needed for planting trees - grants available though

But it is the best fun you will ever have though and I've got energy coming out of my ears at the moment. Energy price increases - what are they?]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12829#Comment_12829 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12829#Comment_12829 Sat, 19 Jan 2008 12:27:26 +0000 richardt
That doesn't include an old Unimog for hauling firewood (which does other work too)and 3pl splitter btw.

Scottish Shower quoted us around 18k for a mains hookup.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12832#Comment_12832 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12832#Comment_12832 Sat, 19 Jan 2008 13:14:45 +0000 tony Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12842#Comment_12842 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12842#Comment_12842 Sat, 19 Jan 2008 17:55:23 +0000 GBP-Keith Put in a good woodstove now. In ten years time they will be difficult to obtain due to over-demand.

If you only have half an acre of land, plant half of it now with ash trees in a semicircle around the north of the other half. You will need the rest to grow food on later.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12956#Comment_12956 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12956#Comment_12956 Mon, 21 Jan 2008 11:53:51 +0000 StuartB Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12992#Comment_12992 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=12992#Comment_12992 Mon, 21 Jan 2008 17:09:21 +0000 dazdread Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13012#Comment_13012 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13012#Comment_13012 Mon, 21 Jan 2008 19:56:06 +0000 GBP-Keith
Have you taken a look at the Skystream 3.7 wind turbine from Southwest Windpower Stuart. It looks really quite economical and could help you keep nearer your budget. The guide prices seems to be about £6500 + groundwork. That's about half the installed price of the Proven! (Plus batteries etc of course).]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13121#Comment_13121 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13121#Comment_13121 Tue, 22 Jan 2008 21:38:16 +0000 chipedwood
Also I wouldn't recommend any solar equipment in the UK as it is not efficient enough to pay for itself even in the long run. They normally are out of their lifespan by the time they would of become useful.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13122#Comment_13122 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13122#Comment_13122 Tue, 22 Jan 2008 21:48:16 +0000 chrisc Posted By: chipedwoodAlso I wouldn't recommend any solar equipment in the UK as it is not efficient enough to pay for itself even in the long run.

But I guess you are comparing with the cost of fossil fuels and perhaps you haven't appreciated that peak oil is probably in the past (or if not will be in a few years at most) and peak gas isn't going to be far behind and peak coal might be as soon as 2025 -- annual 10 to 20% fossil fuel prices rises are probably going to be the norm for the next few years...]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13152#Comment_13152 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13152#Comment_13152 Wed, 23 Jan 2008 10:06:41 +0000 StuartB
stephendv - 6.7kwh seems very high for a 2 bed house! We are currently burning 7.9kwh in a not particulary efficient 4 bed home, I would hope to get this down considerabley with a new build.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13155#Comment_13155 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13155#Comment_13155 Wed, 23 Jan 2008 11:07:44 +0000 Paul in Montreal Posted By: StuartBstephendv - 6.7kwh seems very high for a 2 bed house! We are currently burning 7.9kwh in a not particulary efficient 4 bed home, I would hope to get this down considerabley with a new build.

I think you're getting mixed up between kWh and kW - 6.7kWh is very little over a 24 hour period - equivalent to less than 3 100W lightbulbs. At the electrical rate I pay, that would be equivalent to around Can$140 a year. If, as I suspect, your load is 7.9kW, you'd consume around 190 kWh in a day which sounds more like it for an inefficient 4 bedroom house in winter in Scotland!

Paul in Montreal]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13157#Comment_13157 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13157#Comment_13157 Wed, 23 Jan 2008 11:32:20 +0000 StuartB Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13170#Comment_13170 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13170#Comment_13170 Wed, 23 Jan 2008 13:35:57 +0000 Paul in Montreal Posted By: StuartBPaul, you are correct, excuse my maths. It was 70,000kwh for the year.

Wow, that is an astounding electricity consumption! You're right that it's not very efficient! We scrape by on 25,000kWh per year in a much colder climate than you for what is probably a similar sized house. What form of heating system do you have?

The original poster was talking about lighting and appliance consumption only so 6.7kWh per day is not too bad. My baseload is around 10kWh per day (measured during the period between the heating season and the cooling season) - and a good part of that is the computer equipment.

Paul in Montreal]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13171#Comment_13171 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13171#Comment_13171 Wed, 23 Jan 2008 13:58:12 +0000 StuartB
Paul - I was in Ontario and Quebec last summer and had a fantastic time, Canada is definitely somewhere I could live. The quality of life is so much higher than the UK. Lovely hot summers too which I guess helps you get through the freezing winter!]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13175#Comment_13175 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=13175#Comment_13175 Wed, 23 Jan 2008 14:43:43 +0000 Paul in Montreal Posted By: StuartB4,681mWh for electric and 22,300 kWh for gas which is how I got to 70,000 for the year. Does this sound excessive/incorrect anyone?

I'm not sure how you summed these to 70,000kWh. The sum is 26681kWh which is much more reasonable.
Posted By: StuartBCanada is definitely somewhere I could live. The quality of life is so much higher than the UK. Lovely hot summers too which I guess helps you get through the freezing winter!


Yes, the summer certainly make up for the winters - though last summer was not particularly hot, though it was sunnier and average and also wetter too - though most of the rain was at night. It gets as much above freezing in summer as it goes below freezing in winter - it's like there's a big +30C / -30C switch that gets thrown twice a year :wink:

Regards,

Paul in Montreal.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=45666#Comment_45666 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=45666#Comment_45666 Sun, 01 Feb 2009 23:42:17 +0000 valasay Water sourced heat pump from sea loch 100m from house with a 50m drop to sea level and 20kw wind turbine to replace 10000kwh electricity and 5000l of oil
We live in an exposed location in the Outer Hebrides of Scotland in a timber framed house built 11 years ago. It makes total sense to insulate more effectively as the building regs which applied at the time of our build were the same whether in the centre of Edinburgh or on the coast, next stop America.
There are vents under the floor, in the walls, along the soffits and in the roof space, hence draughty house with 180 mms insulation in walls but huge energy bills. This is probably a silly question but how do I improve insulation/air tightness without compromising the ventilation required for the timber frame?
All suggestions gratefully received!]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=45790#Comment_45790 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=45790#Comment_45790 Mon, 02 Feb 2009 22:16:39 +0000 robJH
I'm sure you can drastically reduce your consumption below those values! Just for info, here's how we do it.

I have a 1930s semi (110m^2 total floor area) in Sheffield and this year the house has been occupied 24/7 due to the arrival of our baby in Jan 08. We have used around 6000kWh of gas and 5.2kWhr/day of electricity in the last year - and we have an electric cooker (not my choice, I'd like to add!). We have a new combi boiler and a wood burning (5kW) stove.

Central heating is only on for around 45mins in the morning and only ever on in rooms that we use. It is on for around in hour in the evening, but most importantly of all, the thermostat is set to around 13-14 degrees. It gets the kitchen warm enough for breakfast and the stove is then lit which keeps the lounge at between 17 and 20. The stove keeps the dinning room to around 16-18 degrees as well.

So I would think it is probably possible to significantly reduce your energy consumption and as a result, significantly reduce some of the costs of your renewable energy generation.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=45811#Comment_45811 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=45811#Comment_45811 Tue, 03 Feb 2009 01:09:00 +0000 pmcc
Completely agree that before looking at how to generate heat you should first look at how to keep it.

There seem to be well understood techniques for lofts, although it can be rather messy and complicated for timber frame houses with many voids. Lots of threads on this forum discussing them, plus lots of materials on the web. I just so happen to have these links open, but many others explain in more detail.

http://www.xtratherm.com/products/saferpitchedroof.php
http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=3466&page=1#Item_0

The walls are the biggest problem. I'm looking at external insulation, but the cost would make your eyes water. Other options are to rip off plasterboard for external facing walls and stuff insulation into the gap. Or to put up some insulating wallpaper type of stuff.

For under the floor, I'm afraid the only options I've seen discussed seem to be cutting rigid insulation board and fixing between the floor joists. The joists are a cold bridge, but must be ventilated to avoid condensation and rot.

I have a whacky idea, but I'm not a builder so it will probably be silly. In essence, put insulation above the foundation concrete, block off the under-floor air vents to the outside, and install wall vents on the inside. The space between the internal walls and external wall becomes warm. Insulation is outside the external wall so heat is not lost too fast.

Probably this deserves its own thread...]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=45862#Comment_45862 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=45862#Comment_45862 Tue, 03 Feb 2009 12:24:29 +0000 fostertom Posted By: tonyInsulate and get airtight then work out heat loss then think about how much solar heat you can use then think about an inter-seasonal thermal store (needn't be expensive) then see what you maximum base load will be then look at reducing that then size your generation or storage capacity.That should be on a banner across the top of every GBF and AECB page! Says it all.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=45868#Comment_45868 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=45868#Comment_45868 Tue, 03 Feb 2009 12:35:49 +0000 MarkH Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=46065#Comment_46065 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=46065#Comment_46065 Tue, 03 Feb 2009 23:06:42 +0000 pmcc Posted By: MarkHpmcc - we chose to have Warmcel blown behind our plasterboard between the timber frame. We already had 25mm of EPS (and then a 75mm gap). This seems to have been effective (we think the walls now have a u value of 0.35 or better), and although just as messy as ripping off plasterboard to fill the stud work with rigid insulation, it was about 20% of the cost if my memory serves...


Interesting - from various conversations and general reading I had formed the impression that blown-in insulation wouldn't work for timber frame. Could that be because there is sometimes a vapour control layer outside the studs, which would trap moisture and cause rot?

Also, for some reason I thought there had to be some sort of gap immediately behind the plasterboard to allow for electric wires and other services. In my house making such a gap that would mean ripping the plasterboard off anyway.

Did you fill up the whole space between the foil back of the plasterboard and the wood on the outside of the studs? Presumably you drill a hold in the plasterboard and spray it in? If so what happened to stuff like wiring - just trapped inside the insulation? Warmcel is supposed to have effective fire suppressants, but I wonder about fire risks from loose electrical connections...

Sorry for so many questions - I've not seen a good explanation of this elsewhere.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=46341#Comment_46341 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=46341#Comment_46341 Thu, 05 Feb 2009 13:23:17 +0000 MarkH
I'm no expert, relying mainly on the Warmcel technical people and the installers - very helpful.

Drilling the holes through the plasterboard meant going through the vapour barrier. The company installing the Warmcell ran a calculation to show that the risk of condensation was below the levels required. As a belt and braces approach we have used a sealant overs the patched holes to minimise vapour transfer. Also, the Warmcel was blown in dry not sprayed in wet.

Regarding electrical cables - yes we do have a few in the external walls, and yes the cables are now buried in Warmcel. Again there is some building software which showed no problem. (If you have cabling that is pre PVC covered that might be a problem).

We have assumed no electircal cable connections in the Warmcel - connections are in the wall socket boxes or in the loft.

Hope that helps. If you want more its worth speaking to the Warmcel tech guys. If I remember when I'm at home I'll dig out the name of the installer for you.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=102598#Comment_102598 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=102598#Comment_102598 Tue, 15 Feb 2011 21:13:07 +0000 renewablejohn Posted By: StuartBIs it possible to be 100% off grid for a maximum capital outlay of £15k? Location - rural, exposed south facing half acre plot in Scotland with am average wind speed of 6.1.

What renewable technology would you use to provide all your heating and power needs for a 4 bed house? If it can't be done for less than £15k how much do you think it would cost?

You could go down the biomass CHP route especially as it is eligible for ROC's and RHI when it comes in.

10kw solution for $16995 20kw for $25995 plus shipping and import duties.

http://www.gekgasifier.com/gasification-store/gasifier-genset-skids/]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=102725#Comment_102725 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=102725#Comment_102725 Thu, 17 Feb 2011 09:37:39 +0000 fostertom Posted By: renewablejohnWhat renewable technology would you use to provide all your heatingI answered you that but you poured scorn on it, poss because it wasn't a bolt-on 'technology' but something more integral in the (re)design of the house's fabric.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=102739#Comment_102739 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=102739#Comment_102739 Thu, 17 Feb 2011 10:54:56 +0000 renewablejohn Posted By: fostertom
Posted By: renewablejohnWhat renewable technology would you use to provide all your heating
I answered you that but you poured scorn on it, poss because it wasn't a bolt-on 'technology' but something more integral in the (re)design of the house's fabric.

Fostertom

Just to clarify it was StuartB who posed that question even though the system suggests that it was posted by me.]]> Offgrid - how much will it cost? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=102762#Comment_102762 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=1125&Focus=102762#Comment_102762 Thu, 17 Feb 2011 16:25:20 +0000 fostertom
That is, about enabling the building to collect, store and use 'renewable' energy in an extremely lo-grade form:
Collecting solar heat by collectors operating at very low flow/return temp, about 21C, which reduces re-radiation loss to cold outside scenery, so that even in Jan/Dec there's useful and sufficient nett gain
Transporting that heat to very massive heat store e.g. all the walls of the building - massive enough to store enough heat in lo-grade form for long enough to bridge over Jan/Feb sunless spells
Inputting that heat to the interior over large enough radiant area e.g. all the walls of the building, that very low delta-t is sufficient.
So if desired inside temp is 17C, inside radiant wall temp needs to be 17.5C, outside temp of same walls 20C, thermofluid inputting heat into outside of walls @ flow temp 22c, return temp 20.5C.

Only space heating can make user of solar heat collected at such lo temp (tap water, electricity etc can't) - so at least do your space heating that way, which makes it possible right thro Dec/Jan - and is inherently off-grid.]]>