commercial planning

[TedM]

Sorry, the limit for domestic and non-domestic permitted development is 50kW.

The PD refers to 'microgeneration' which is defined as up to 50kW at section 26(3) of The Climate Change and Sustainable Energy Act 2006. Climate Change and Sustainable Energy Act 2006

HMRC also refer to this same maximum limit when applying the tax exempt status.

No coincidence that this is also the MCS limit as well.

 

[Gavin A]

so it is.

Though it actually references the definition in the energy act 2004 in that planning document, the wording of the definition from there is below.

(6)​

For the purposes of this section “microgeneration” means the use for the generation of electricity or the production of heat of any plant—

(a)​

which in generating electricity or (as the case may be) producing heat, relies wholly or mainly on a source of energy or a technology mentioned in subsection (7); and

(b)​

the capacity of which to generate electricity or (as the case may be) to produce heat does not exceed the capacity mentioned in subsection (8).

(7)​

Those sources of energy and technologies are—

(a)​

biomass;

(b)​

biofuels;

(c)​

fuel cells;

(d)​

photovoltaics;

(e)​

water (including waves and tides);

(f)​

wind;

(g)​

solar power;

(h)​

geothermal sources;

(i)​

combined heat and power systems;

(j)​

other sources of energy and technologies for the generation of electricity or the production of heat, the use of which would, in the opinion of the Secretary of State, cut emissions of greenhouse gases in Great Britain.

(8)​

That capacity is—

(a)​

in relation to the generation of electricity, 50 kilowatts;

(b)​

in relation to the production of heat, 45 kilowatts thermal.

Energy Act 2004


I'd entirely missed that, as there is no definition in the permitted dev document, or any size limit mentioned. They could have given us a steer by actually stating it in the PD legislation instead of assuming everyone knew

 

[SolarCity]

I stand corrected. Thanks Ted.

I'm surprised that kWp size affects planning. I don't really see what the amount of power generated has to do with it.

 

[TedM]

I can see no justifiable reason for the limit on non-domestic. If the roof is big enough to take whatever size PV without contravening the edge spacing condition then it is likely to have minimal impact. But for some reason it is there.

50kW = permitted, 50.01kW = planning permission.

 

[njcuk]

Thanks Ted.

I note you said 50kW has a tax exempt status. I presume this is if it was bought by an individual?

 

[TedM]

That is the upper limit on size for the domestic tax exempt status to apply, yes.