SAP calculation figures vs. PV SOL figures

[SolarCity]

I am becoming increasingly frustrated at the survey handcuffs we all have to wear regarding performance figures. While I can see the benefit of maintaining an industry standard for evaluating system performance, I find it a little baffling that we use such a vague and general standard such as the SAP calculations.

A SAP calculation will suggest that a 1.98kW budget system with 20% shading (significant in my opinion) installed at the northern tip of Scotland will offer a higher yield than a 1.97kW system using Sanyo HIT panels with zero shading installed in Cornwall.

In my opinion, this is a crazy suggestion and utterly misleading to a customer. When I approach a customer, I want to be giving him the best possible advice that I can offer. Surely software such as PVSOL should be given MORE weight than this embarassingly vague SAP calculation?

 

[Markc]

You are able to use the figures suggested by PVSOL or alike as long as the SAP values are also included within a quotation and the designed figures are no more prominent as those by SAP. We put both figures in our quotations. SAP does not allow for location in anyway shape or form.

 

[Noshocks]

I have been told that the latest SAP figures will be based on three or four locations of the UK in the future (NICEIC assessor), they are currently based on Sheffield, dont know when this new data will be available though.

 

[SolarCity]

Yeah, we also use both sets of calculations. However, I think this is confusing for the customer and it is difficult not to explain exactly what these figures show without inadvertently giving the PV SOL figures more prominence.