Geogrpahic Irradience Factor

[JamieK]

Morning

Ive been tasked with working with our web developer to generate our own Feed in Tarrif calculator on our website but have a few questions on the calculations we need to use.

Im using the SAP figures (2009) from BRE and the equation 0.8 x kWp x S x Zpv and that is all simple enough to code, combined with the 2011 Feed in Tarrif rates but the bit that has thrown me is that most online calculators split the UK up into 5 irradiance zones (like the one below).

https://www.government-grants.co.uk/feed-in-tariff.shtml?gclid=COa24e2cwKkCFYEc4QodrVamgA

I havent got a clue where to look for the factors to combine this into my caluclations - does anyone have any knoweldge of this or may be able to point me in the right direction - I'd be glad to share the claculation spreadhseet on completion before we turn it into code for the web page which may help others attempting to do the same thing?

Thanks

 

[TedM]

SAP only uses a single factor for the whole of the UK.

If you want to show other calcs in addition to SAP then PVGIS PV potential estimation utility can probably give you all the other data you need.

 

[Ramjam]

MCS is clear, SAP 2005 with no alterations for regional irradiance, why do you want to break the rules?

 

[JamieK]

Fair Comment - to be honest I canned the idea anyway as I coudlnt find the numbers I needed and was just too much hassle.

I think the idea was to give a more specific estimate to the customer but I completely agree with your point, thats the route I took in the end.

I used SAP 2009 though to get my figures.

 

[SolarCity]

I used SAP 2009 though to get my figures.

You should really be using SAP2005 - for reasons that I have yet to fathom.

 

[JamieK]

Ive got my MCS assessment at the end of the month - I wanted to double check with the assessor then as I know in the DTI Guide 2nd Edition it says use 2005 but surely we must be using the most up to date version of the BRE document!

I havent actually checked to see if the figures are the same they might be.

 

[Ramjam]

The 2009 will give a slightly more favourable estimated yield. If you use 2005 then you are compliant, nobody can put you in trouble and the payback is plenty good enough.