How Do I Get Round This?

[SRE]

1960's bungalow, cavity wall insulation, 8" loft insulation, good boiler controls, 87% efficiency rating for boiler, low energy lighting - walk in the park for EPC ..... NOT. It's lpg and no matter what our EPC guy does we can't get it up to a D rating, without replacing the boiler for oil which would need a new bunded tank or ashp which would be totally inappropriate for this particular bungalow as well as costing a fortune. Biomass reduces the EPC rating instead of increasing it.

How can this possibly be fair when a customer with natural gas and very little insulation can often get the full Feed in Tariff? Our EPC guy reckons changing the lpg boiler will only increase the efficiency to 93% and when he's put the figures through it's still short of the D rating.

So - biomass reduces the rating, the embodied energy involved in changing an lpg boiler is greater than the CO2 savings that would be made by gaining 6% extra efficiency and he can't have pv at the full feed in tariff to increase his EPC. The world has well and truly gone mad!

 

[whinmoor]

Can you install more than 4kWp of PV? Front, back and sides? And in the garden and on the garage?

 

[SRE]

Hadn't thought about that - doh! That actually might make a difference. There's a bit of spare roof if we can get DNO to agree to an increased spec.

 

[The Solar King]

May find you can do 5.5k up North and not breach G83. I know Gavin has done this with EW systems. EPC software should take up to 7kW of PV.

 

[jason121]

I have never managed to go over 5.5kw in my area with DNO, on domestic installations

 

[The Solar King]

Have run this through PVSol on a number of occasions. Have never seen clipping of inverter output. We do have less irradiance. If the inverter does clip, you will be able to count the occurances on your fingers.

 

[Worcester]

Just remember the FiT is now definitely based on the panel rating so it will be in the 4-10kW band, however even that is better than the alternative.
No reason why not to connect the 5.5Kw to a 16A G83 inverter and therefore not need DNO notification.
Does the EPC take account of location, orientation etc or just # of panels and W ?

 

[The Solar King]

With regard to EPC, the answer is I don't know and can't find out until I am back home in a weeks time. Only know about 7kW as am looking at an east/south/west job where we may fit 7.2kW and needed a ball park as to whether it would lift the property in to a D. (Which we think it will).

 

[Gavin A]

not enough info.

what points exactly is it on, and is this before or after the PV?

Off the top of my head, increase to 300Wp LG panels = 4.8kWp should gain a couple of points, no need to go above 16amps on the inverter, the limiting will be less than 1% of generation across the year, and the inverter will be operating more efficiently at lower outputs when the extra energy will actually be used in the house.

Or use an east / west roof as well and add another 2-2.5kWp on a dual tracker eg 3.6out-d or probably 3600TL-21 so the higher voltage range will allow for all 16 panels on the one string.

extra insulation jacket on the cylinder? Maybe see if the EPC assessor would rate an immersun as a solar water heating system, or check what impact electrically heating the water would do to it with a larger amount of solar PV. If it's a bungalow it may actually be worth adding an extra layer of loft insulation as proportionally more of the heat goes through the loft.

etc

We got an LPG fired renovated detached stone cottage through a while back, but only just with a 5kWp 2 roof system, and needed extra loft insulation, us to proof that there was a thin cavity, extra heating controls etc.