MCS Guide to the installation of Photovoltaic systems (shading analysis)

[Gavin A]

PVSOL is exceptable

in what way?

As it's currently written, it's only acceptable as an additional method, not on its own as far as I can see.

 

[jason121]

Just had my audit today, inspector mention any form of survey to verify shading will do. If PV Sol predicts 10 % shading transfer that into your quote prediction. 1 is now .90

 

[infinity]

That also how I read it...

 

[Gavin A]

Just had my audit today, inspector mention any form of survey to verify shading will do. If PV Sol predicts 10 % shading transfer that into your quote prediction. 1 is now .90

he's applying common sense then rather than the specified MCS methodology which only allows that method as an optional extra on top of the MCS method.

What he's done there is to basically apply the approach myself that I and TSk have requested be inserted into the current wording of the guidance, which is all very well, but leaves it up to the judgement of the individual MCS assessor as to whether to apply the letter of the MCS requirements or use a common sense approach. What I'd want to see is that this is specifically written in to the MCS documentation, otherwise you might be fine, but another company might be given a none conformity for using the same method and forced to adopt the MCS methodology instead / as well as a more accurate method.

This is how the guidance puts it currently

“Additional estimates may be provided using analternative methodology, including proprietary software
packages, but any such estimates must clearly describe
and justify the approach taken and factors used and must
not be given greater prominence than the standard MCS
estimate.”


“In addition, it must be accompanied by a warning stating
that it should be treated with caution if it is significantly
greater than the result given by the standard method.”

 

[The Solar King]

Good points as always from Gavin. I am also with NAPIT and will find the right person to copy in tomorrow. Gavin will also have noticed I have blagged a few lines of his from responses to Martin Coterell's Solar Power Portal Blog. Trust you don't mind and that this is sufficient recognition of your authorship.

Also copied my trade body the STA and Chris Laughton of the Solar Design Company whom I am aquainted with. Quite an interesting response from Chris who has also had concerns from early on in the process. Some of you I know have read his blogs.

The important thing now is resolution, not people digging their heals in.

 

[whinmoor]

Who's actually using the MCS approach on a regular basis? We've tried a few times but often run into difficulties:

* Once the only available window was in a bathroom with frosted glass so that wasn't very helpful.
* It doesn't really work on an east-west split because it's difficult to look south.
* It's a bit tricky to handle all the tools, paperwork and pen whilst clinging on to a ladder in the wind and rain and following the "three points of contact" rule.

Totally impractical and highly dangerous in many cases.

 

[The Solar King]

Who's actually using the MCS approach on a regular basis? We've tried a few times but often run into difficulties:

* Once the only available window was in a bathroom with frosted glass so that wasn't very helpful.
* It doesn't really work on an east-west split because it's difficult to look south.
* It's a bit tricky to handle all the tools, paperwork and pen whilst clinging on to a ladder in the wind and rain and following the "three points of contact" rule.

Totally impractical and highly dangerous in many cases.

Please write and tell them so. What you have to say is as valid as any other comment made. Go for it. [email protected] Or if you have a contact address for the Heid Yin, use that.

 

[jason121]

This is the reply from my MCS inspector, Sounds like a very considered comment to me.

 

[jason121]

Look at summary of methods PVSOL at bottom of page

 

[The Solar King]

This is the reply from my MCS inspector, Sounds like a very considered comment to me.

Nothing showing to look at. Try uploading it again

 

[Gavin A]

Look at summary of methods PVSOL at bottom of page

but section 8 then states that you have to transfer the information from PVSOL onto an MCS horizon chart, then use the MCS method to calculate shading, so you can't just use PVSOL to calculate the shading.

Step 4 … transfer data onto MCS chart (using same method employed for basic compass method)

 

[jason121]

Yes. Keep up the fight.

 

[Gavin A]

tbf, that does at least answer the health and safety criticism, although they really need to make that clearer in the guidance.

The issue remains around the inaccuracy of their method then.

 

[Worcester]

Well if any of you have been using the Sunpath Indicator / Solar Shading Meter from test-meter.co.uk here's the foil as shown in the new shading guide :
Moderator - do you want to move this post and make it a sticky?
View attachment sss-foil-mcsaid-V3-rp.pdf I've rebundled it as originally it was 2.5mb


the foil is a free download from here: MCS Shading Method - Download free MCS-aid foil from The Solar Design Company

 

[jason121]

I shall be using the trig calculation. That way I don't have hang out a window. transfer onto midsummer shade tool online.