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I am part way through installing an off-grid solar PV and wind turbine feed for a summerhouse and wondered if anyone has any experience or tips. One strange piece of info is that a first small turbine or ASHP is permitted development (conservation areas excluded) but if you already have a Heat Pump then you would need planning permission for a wind turbine.

I have a small control system with battery storage which the panels and turbine will feed into and an associated power dump protection once the battery is full. It is a relatively small system but something that will power lighting, cooling and a small heater in winter. Once all in place I will post some photos for info.

Sounds like just what I need, although it would have to produce about 3kW. Fat chance of my landlord agreeing with me, though. I’ll be interested in hearing how it goes, perhaps with some idea of the costs involved … good luck with getting it all up and running 👍


When you say a small turbine is it the type some yachts have ? My neighbour has one a similar size to that but he’s surrounded by trees and I rarely see it turning ☹️ I’d love one !


Sounds like just what I need, although it would have to produce about 3kW. Fat chance of my landlord agreeing with me, though. I’ll be interested in hearing how it goes, perhaps with some idea of the costs involved … good luck with getting it all up and running 👍

Thanks - this is rather small scale (about 1000 W peak) but not that expensive .. around £500 for all the hardware and fairly easy to install. When I mentioned it at home my daughter wanted a water wheel as well (we have an off run from the hills nearby) but that seemed a little optimistic. 


When you say a small turbine is it the type some yachts have ? My neighbour has one a similar size to that but he’s surrounded by trees and I rarely see it turning ☹️ I’d love one !

Yes, that’s the type of thing. I’m told it can go to around 11 m high but it’s really just as an experiment and to complement the solar feed


@TerryE may be able to advise. I have it in my notes that they have built a passive house…


@TerryE may be able to advise. I have it in my notes that they have built a passive house…

Ok thanks for that but … have you changed the title of this? It’s Off-Grid so nothing to do with DNO


@BPLightlog you are absolutely right, and I’ve now changed this back. I hope you don’t mind my meddling I just want to make sure everyone searching can find this online. Let me know if you want any other changes to the title. 

 

Sadly it seems @TerryE isn’t joining us. @krankyd I’ve got it in my notes that you have a wind turbine. Are you about?


HI,

I’m not about often lol :)

There are requirements to meet if you don’t require planning permission for a turbine, take a look at https://www.planningportal.co.uk/permission/common-projects/wind-turbines/planning-permission-stand-alone-wind-turbines for reference, but as always contact your local planning office, they should be able to give you an idea if it’s permitted development or not. They do mention ASHP etc. 

my turbine is massive - 11kw - and had full planning as it’s huge. The DNO has to be notified if you’re using an on-grid connection, and it’s likely there will be some cost element with this, but if you’re getting it installed via a MCS certified installer they’ll take care of all of this. However they will add extra $$ onto the price just to be MCS certified..  If you’re off grid you have to consider dump loads and be available to pump spare electricity into this at certain times instead of feeding it back into the grid. 

You could install the turbine first then install the ASHP, as the requirement for no planning is only if the ASHP is present when the turbine is being installed…. 

To be totally honest ( I think not the answer you’ll be looking for..) , I would not think a small turbine would be enough to contribute much to any off-grid system, unless you’re in a properly well exposed, windy area. You’ll most likely be paying 2K+ for something that generates only tens of KW per year, solar would almost always be a better option, require less planning, require less maintenance and be cheaper. For the price of a turbine you could potentially double your solar install costs that has no maintenance or moving parts (turbines require regular maintenance or they fall apart)

We live in the highlands of Scotland, and we regularly get winds up past 100KPH, and our turbine is in an excellent location, free from hills and obstructions for a long way around. It generates easily 200kw on a good day, but as I’ve said we’re really windy, and we have a very large install.


This is what I mean by ideal site :) 

 


@TerryE may be able to advise. I have it in my notes that they have built a passive house…

I did. I liked @BPLightlog comment that Off-grid solar is nothing to do with PassiveHouse optimisation.  The one comment that I do have is that whilst the DNO may limit consent to export to the grid, many PH owners with solar get around this by implementing this outbound limit themselves in their control and conditioning, e.g. using a decent amount of  battery and thermal storage.  The cost of battery storage if you want SME-scale continues to fall at 15-30% p.a. and if the Sodium-based technologies come into the market then this rate will accelerate. 

This Canadian Youtuber has a range of related video posts, e.g:  Surprising Truth About Off-Grid Solar.  The cost economics of field-installed PV and small WTs is that you will end up with maybe 2 month a year when you rely on a DNO input, or backup generator, 5 where you “balance” the books and 5 where you have energy excess.  (This `2:5:5 ratio depends on your current investment in such generation infrastructure.)  Whatever the ratio, the three zones still remain and you need to address all three cases in your design, especially what do you do when you have too little local energy and what do you do when you have too much?  I know someone with a 1m³ tote that he has 200mm insulation around and dumps any excess electricity into this by an immersion heater as a thermal store, but a plastic tote still has a upper safe temp limit (~60°C) so at some point you may still need to be able to dump excess elsewhere.  Even 3 kW export to the DNO can give you a deadband that makes this a lot more workable.

This issue of falling prices complicates the optimum, eg. do I do a part solution now, because deferring the rest by say 3 years gives a better overall RoI. 


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