home of the Sliding House

   The website of Ross Russell and Sally Morris:
   documenting progress on our project to design and build our house in Suffolk in the far east of England.

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Planning consent

You need planning consent for anything more than a toy turbine.  My local council is Suffolk Coastal District Council I got my consent from them on 3 August 2009. Here is a copy so you can see what a consent letter looks like and the sort of conditions they like to impose.

There is a fee for any planning application – in my case £130 for consent for a wind turbine and another £130 for a change of use of the land on which it stands.  Although it is classed as a domestic wind turbine it is just outside of the “residential curtailage” of the house and so the permitted land use had to be changed from agricultural only to something less restrictive. Your local council will tell you what the fixed scales of charges are.  They are the same across the UK.

Nowadays all local councils like you to make your application via the online “planning portal” at www.planningportal.gov.uk.  But you still need to submit various things by post or by hand (such as a cheque for their fee) and I found that it was better to send them hard copies of plans and the like also.  My local planning officer lost my electronic application for four weeks and delayed the project by a similar period.

The manufacturer has a useful planning pack which covers much of the stuff that planners need to know about. A link to this is here

I attended the planning committee meeting itself to answer any questions they had. Here is a copy of what the planning officer submitted to that meeting (again so that you get a feel for how these things are presented). The key issues for the planning committee were these.



It is now a requirement driven by EU law that the interests of bats are taken into account when any development is proposed and this is taken seriously where turbines are concerned.  There is a fear (based on anecdotal evidence from one or two commercial wind farms in the USA) that a turbine will create sudden changes in air pressure as bats fly behind the turbine, which disrupts their navigation system and causes them injury.    The local planning officer will take advice from specialists (in this case the Suffolk Wildlife Trust).  I wish I had spoken to the wildlife trust directly and earlier in the process – the planners themselves only made contact to seek their view a week or so before the committee meeting at which this was to be considered so if they had, for example, insisted on a bat survey then the whole project would have been delayed again.  In the end the wildlife trust raised no objection to my proposed turbine or to its proposed site. To get their support I did change its position to site it further from a nearby hedgerow (bats apparently use hedgerows as their equivalent of motorways and their concern was bats flying by along the hedge not that they were roosting in it).  

At one stage they quoted at me guidance from Eurobats (www.eurobats.org) that said that turbines should ideally be more than 50 metres from any hedgerow, hardly a possibility for most domestic turbines, but in the end they acknowledged that this guidance should not be applied directly to domestic turbines.  You can find the guidance here: www.snh.org.uk/pdfs/strategy/renewable/B259918.pdf in case you need it to argue your case and below are the comments from the very helpful people at Suffolk Wildlife Trust.


Dear Chris

Further to our telephone conversation today I have the following recommendations:

I think that the amended location for the wind turbine is much more acceptable with regards to its proximity to the hedge.

The Natural England Technical Information Note TIN051 is helpful with regards to the large turbines and states that there should be a 50m buffer between them and tree rows or hedges. However, whilst they acknowledge that similar issues apply to commercial, domestic and micro-wind generation, the guidelines do not cover these sort of turbines.

In the context of this site, bats are recorded within 1km, but there is no known bat roost in the immediate vicinity.  If the new location is aceptable, I think it would be reasonable to assume that a bat survey would not be necessary to determine whether the bats are using the hedge as a commuting and foraging route.  If Mr Russell wishes to site the turbine in the original location, I would advise that a bat survey is carried out.

In addition I would like to draw attention to the following paragraphs in my colleague Trudy Seagon's letter of 29th June relating to ongoing research:

Research in to the effects of domestic turbines is ongoing and requires the help of turbine owners to collect information on how bats (and birds) interact with turbines. This may lead to the development either of turbines that do not kill these groups or of deterrents that can be installed to keep bats and birds away from rotors. We would therefore ask, should permission be granted, that the applicant is requested to report any bat mortalities that might be connected to the turbine either via the Bat Conservation Trust or to Stirling University who are conducting research in to this subject – a link to their online questionnaire is below.

Information regarding turbines that do not have an impact on bat populations will also be very useful to this study so we would ask that the applicants complete the questionnaire after the turbines has been operational over, say, a summer season regardless of whether there is believed to be any impact on bat populations.


If this can be made a condition of planning consent this would be helpful, otherwise as an informative note.

Yours sincerely



This was not raised as an issue by my planning officer nor the committee.  Maybe because the planning information pack that the manufacturer, Proven Energy, provided addressed the concerns directly. Frankly, a domestic turbine is not going to damage birdlife at all, as evidenced by the fact that the RSPB support the use of wind-turbines (see www.rspb.org.uk/ourwork/policy/windfarms/index.asp). The bigger dangers to bird life where we live are the cats kept by farmers nearby and the glass panes of the house itself (which birds seem unable to resist flying into, thus concussing and sometimes killing themselves).



This is the perennial bugbear for anyone wishing to install a wind turbine.  Turbines are not silent and a quick Google search will reveal dozens of sites for organisations dedicated to opposing new developments on the grounds of expected noise problems. 

In my case the solution is one I don’t really like but can live with: a planning condition relating to noise.  If the turbine increases the level of background noise by more than 5 decibels (using a specific definition of noise measured in dB(A) and averaged over a period with a mechanism for stripping out the impact of occasional passing cars and barking dogs – the LA(90) measure).  It means that, if anyone complains about the noise level at their home, then the Environmental Health Department will investigate and may ask to measure the noise level at that neighbour’s home with the turbine operating and with it braked to a halt.  If the difference is more than 10dB(A) then that constitutes a noise nuisance and they are entitled to tell me to cease operating the turbine at all. This would be a pretty nuclear option given the investment I will by then have made in kit which would be useless for any other purpose.  If the difference is more than 5dB(A) then that will be a breach of the planning condition, the remedy for which is less clear.  

The good news is that only residents can complain and only about their own property, so any busybodies who just want to make a fuss even though they live miles away will not be listened to.  The manufacturer of my turbine had commissioned an independent expert report on noise levels (and also power output) which they will make available to customers on request, which is helpful if you can do the maths to work out the expected noise levels at various distances from the turbine – such as the specific neighbours that may be affected. See here for my own spreadsheet as used for this purpose, although beware: it comes with no guarantees as to accuracy! 



Ours is a turbine with 4.8 metre blades and standing on a 15 metre tower.  By contrast our house is about 7 metres tall to the pitch of the roof. It is visible in the landscape, albeit that it is not the tallest item near here – several trees within half a mile are higher. My local parish council (who are consulted on such things and whose members I contacted to invite round for a look) were supportive in principle but objected to the height (which meant that they were not supportive in principle at all – wind turbines don’t work unless they stick up into the wind!).  But in the end the planning process overruled them, on the grounds that they, like all UK planning authorities, are required to look favourably on micro-generation projects.


Building Regulations

The good news is that you don’t need approval from those nice men at building control. A turbine is not considered to be a building so you lash together any old Heath Robinson device and they cannot touch you. But in practice your manufacturer and installer won’t let you do that and those people have a de facto monopoly on installation work, given that you cannot claim the government grant for installing a turbine unless you have a registered installer install a registered product for you.  


Electrical infrastructure

Ours is a grid connected turbine – we buy electricity from the grid when our needs exceed what we generate (like still days in winter) and we sell electricity to the grid when the reverse is true (i.e. it is howling a gale but we are on holiday and using power only for the “always on” things like the sewage treatment plant).

The first thing you have to check is that your local electricity infrastructure can cope with the power you plan to generate.  This ought to be obvious. After all if I can use a maximum of 20kW of power by turning on all the appliances in my house simultaneously, which I can, then the grid must be able to supply it. And if it can supply 20kW to me then it can surely cope with 12kW generated by me? It is not as is those cables they lay are directional and can only cope with power supplied to me but not power generated by me. And given that I am only 13 miles from Sizewell B and it pumps out some 1.2 million kW into the grid, my measly 12kW should hardly register should it?  But the local electricity company (and here we mean the guys that run the infrastructure, not they guys who flog you power and deliver it through that infrastructure) do need to approve your turbine and if they don’t think they can cope then they can prevent you installing one. So do ask. And do so early on, given that any problem they identify can potentially be a show-stopper as it nearly was for me. 

The general rules are that you can generate up to 3.8kW per phase (so 11.4kw on a three phase supply, 3.8kW on a single phase) without requiring advance approval from your DNO. This is gross maximum power output (i.e. before allowing for what you use on site).  The procedure is called G83.  You still need to tell your DNO but they cannot object. In practice I am told that my local company EDF will accept a 6kW turbine on a single phase supply without any problem so there is obviously some flexibility here.

If you want to export more than this, then you need specific approval under a different process, G59.  This requires an engineer to make an assessment of your local infrastructure to determine whether you local transformer can cope with feeding that power back to the 11,000v high voltage grid or whether the users connected to that transformer are expected to use that amount of power anyway so the turbine will actually reduce the load on the transformer. This assessment can take weeks of months.  EDF quote 10 weeks to me and despite repeated chasing that is how long it took.

In my case the infrastructure company is EDF and my electricity supplier is E-on.  You can tell who your supplier is by looking at your electricity bill, but you’ll have to ask a neighbour or your local electrician or do a google search to find the infrastructure company.  You may by the way hear them referred to as your DNO (Distributed Network Operator).  They have local monopolies so if you are in their region then they are the only show in town.

Electricity Contracts

Quite a lot of electricity suppliers have tariffs that deal with the grid connection of domestic turbines, but I found that few had a tariff suitable for my 15kW turbine – most put the upper limit for micro-generation kit at 6kW (and that is maximum rated power, not net or average). In the end I went to Good Energy (www.goodenergy.co.uk) who have a tariff called Smart Energy which is aimed at that section of the market above small scale domestic turbines (say up to 6kW) and larger commercial turbines (their upper limit is 75kW). 

At the time of writing (December 2009) the payments I can get from them are:

£47 per ROC

£42.30 per MWh exported

I pay them for imported electricity at a tariff similar to what others charge (at the time of writing: 14.11p /Kwh day rate; 7.5 p/kWh night rate; 17.05p/day standing charge).  I also pay them £75 for an import export meter and £76.41 per annum for administration costs.


Financial analysis

People ask me what the pay-back period on the turbine is.  As an actuary I regard this as a wholly useless piece of information, although for the record it is about 15 years. The better way of looking at this, in my view, is the return on investment. This can be compared with the return on alternative investments. I have set up a spreadsheet which looks at total returns: see here.  But the gist of it is as follows:

ROCs are payable based on total power generated in a year, regardless of whether you use it or export it.  Since last April you get two ROCs per Mwh as an incentive for small scale generation. – I hope for 20 Mwh (that is 20,000 kWh) in a year and will claim 40 ROCs so £1,880.

Given that the import price and export price differ so much it is pretty hard to work out what I get paid for the power itself – it depends on how much of the turbine’s power I use on site rather than exporting.  The wind is pretty variable so I expect that in practice only a small part of the turbine output will be used directly on site – I have used 25% in my sums.   On this basis:


  The base cost of annual electricity if I had no turbine would be



  With a turbine I will pay reduced electricity bills and other costs of:



  I will get payments from ROCs and exported power of



  Which gives me a net income of


In other words I make an annual return of A plus D which is £2,944.  It would be much better if the 25% proportion were higher, so I’ll be looking at ways to get the heating and other appliances working harder when the weather is windy (which to a degree it will – it is windier in the winter than in the summer and houses, like people, find it harder to retain heat in high winds).

Given construction costs of some £45k, this gives a return on capital of 6.6% per annum, if I assume that the turbine has indefinite life span, or 4.3% if I assume that it conks out after 25 years and is scrapped entirely. The government announced recently that the cash income I get is tax-free and the saving in electricity I would otherwise have bought is of course tax free.  And while that income does depend on continuation of current subsidies via the ROC scheme, it also ignores inflation – and my guess is that inflation of electricity prices is likely to be quite high. Anyway call the return on the turbine 4.3% per annum in excess of inflation, tax free. By comparison I can lend money to the government via long-dated index linked gilts and get a return of about 0.5% per annum, less tax so call it 0.3%. No contest!

All of the above is of course subject to change when the government introduces its feed in tariffs in April next year. I’ll update this when I learn more about how it affects me. 



Do I feel another spreadsheet coming on? Well I set one up to test what power I might get in various wind conditions and it is here.  The power output of the turbine varies hugely with wind-speed – broadly speaking doubling the wind speed increases the potential power eight-fold.  Fortunately the frequency with which the wind blows at various speeds is reasonably predictable using the Raleigh distribution (see www.wikipedia.org/wiki/Rayleigh_distribution for Wikipedia’s explanation).

The manufacturer has commissioned independent tests of their product and published expected power throughout the range of wind-speeds. Their data is here.  In combination, their power output data and an assumed Raleigh distribution of wind speeds will give me a reliable estimate of power

If we get our anticipated 5.1 metres/second average wind here (which remains to be seen) then I’ll get 26MWh of power per annum. For planning purposes I have taken this as 20 MWh so that any surprises are hopefully pleasant ones.  

I’ll paste data for performance here when I start generating.


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