East facing roof.

smiffy · Nov 14, 2011

I am about to rewire a house but the local council says that the house must generate 10% of it's own energy. The problem is that it's an east/west roof. Can we still use solar panels? also how many would be needed. The house will be sold once it's finished so not too worried about long term savings it's only to please the planning department. Also an idea of cost would be useful. There maybe a job for a forum member in the GU35 area if he decides to go the pv route.
All advice gratefully received.
Carl

LightGEN · Nov 14, 2011

'smiffy' I'm struggling to understand why the 'council' is requiring you to generate 10% of energy consumption simply because you wish to rewire a property. Is other work being performed on the property, which requires planning permission?

smiffy · Nov 14, 2011

I expected this question but hoped it wouldn't be asked so i wouldn't have to tell the story...................here goes.

The house was once a 3 bed with an attached garage on the side, then the garage was built on adding a storey ans two more bedrooms making a five bed house on a council estate. it was then divided again into rooms and became a HMO.
Then it was repossessed and my friend bought it to convert back to a 3 bed house and a 2 bed house, the 3 bed was done and completed 2010 and subsequently sold. When he applied to the council for planning permission for the 2 bed they said (among other things) that as the part of the house which will now be the 2 bed has never had a staircase ( it was in the 3 bed side) It is considered a new build therefore new planning regs etc so he must generate his own energy, have a downstairs loo etc etc

unit-electric · Nov 14, 2011

This is new to me too. this is the first time im hearing about planning demanding this

Tony1 · Nov 14, 2011

You can have a PV system with as little as 6 panels which should produce about 1.6 - 1.8 KW, easily 10% I would have thought, even on an east facing roof. Not sure on costings but Denmans an City electrical factors will give you a price for the gear.
Hope this helps

smiffy · Nov 14, 2011

Thank you Tony For the useful info. I will need someone to install though if he decides to do it.

Sunnydaze · Nov 14, 2011

Have you thought about microchp (like Baxi Ecogen?) instead of pv?

LightGEN · Nov 14, 2011

'smiffy', Ok, I understand now. We're currently quoting for a system fof premises, which have been granted permission for change of use, and a 20% renewables requirement has been specified by the local planning department, as a condition of permission. The way to approach this is to have an energy survey performed, this will give you an expected electricity consumption figure from which you can extrapolate a system size requirement. The council will likely require you to justify the sysze of system you install. From there it's 'simply' a case of installing an appropriately sized PV system.

A PV system facing East/West will generate around 20% less than a system facing south (at optimum pitch), so the system need sto be 20% larger than it would otherwise. In our case, the energy assessment led us to a requirement for a 1.5kWp system - the premises will use low energy lighting, which figured favourably into the equation.