MCS May 2013 Guidelines

[Berneray]

Quick question.

Potential customer of mine was given the old SAP2009 calculation by another
company.

When I questioned this they told here its okay to do this as long as they tell
the customer the method they are using.

I know a projection is just a projection but in this case their's comes out 243
kilowatts a year better than SAP 2009.

Is this right.

 

[whinmoor]

Don't think so. There was a period (maybe three months) when both systems were acceptable. Then SAP2009 was phased out and the new MCS calculation method was obligatory.

 

[mmorse60]

Agreed, Everyone should be using MCS method now

 

[The Solar King]

You can use as many methods as you like as long as you provide an estimate using new MCS method and do not give greater prominence to alternatives.

We state this in our reports and quotations. We go on to tell the customer that in many instances the MCS method is pants and why. The MCS output estimate is provided first followed by our one based on PVsol and PVGIS-SAF.

Did one recently where MCS method was understating by 23%!!! I could empirically show our estimate is correct as I have an array on a property not far away that produces at a higher output.