SAP 2005 or SAP 2009??

[SRE]

This has been bugging me for a while so I've asked MCS, REAL and NICEIC for an answer. Still waiting for the answer from MCS

NICEIC say :
As far as the MCS and NICEIC is concerned you can use any SAP calculator, REAL is generally a guide, they are happy as long as the consumer is aware of the average of what the system will produce.

Real say:
The REAL Consumer Code states under section 5.3 (Performance information and predictions)-
“ Members must present calculations using recognised standards or based on those that have been developed for the Microgeneration Certification Scheme (MCS) installer standards for the individual technologies.”

SAP 2005 were the first standards produced for assessing the performance of technologies but these standards will constantly be updated to reflect changes to technology.
You should use the assessment procedures specified by MCS and if they recognise SAP2009 to be used then that would comply with The Code.

Remember if you are using another assessment method (Such as PV Sol) alongside the SAP calculation you should do so in-line with the Consumer Code and follow the guidance which I have included below. Even if PV Sol is based on SAP 2009 the breakdown of how the prediction was produced still needs to be shown.

Guidance on alternative estimates
If a member also presents an alternative estimate calculated by using a different methodology and/or assumptions, then the member must:
1. ensure any figures calculated are in line with the attached EU Joint Research Centre maps (source: EU Joint Research Centre’s PV-GIS http://re.jrc.ec.europa.eu/pvgis/countries/europe/g13y_uk_ie.png) and the table estimating the effect of varying incline and orientation on a typical UK site (source: REA) or with other models that convert for tilt and azimuth
2. specify and justify the methodology/assumptions and factors used
3. explain any difference between the results using SAP and the alternative methodology
4. give at least equal prominence to the SAP estimate
5. Include the following warning, if this estimate is significantly greater than the result given by the standard method:

‘This estimate has been produced using a methodology/assumptions that differ from the Government's standard assessment procedure for energy rating of buildings. You should consider both estimates together.’


So - I'm going to be doing SAP 2009 from now on and saving shed loads of time when I could be sleeping!!!!

 

[SolarCity]

I think it is the MCS that specify SAP2005 so I'd be careful going with SAP2009.

Frankly, the NICEIC's response is pathetic - "they are happy as long as the consumer is aware of the average of what the system will produce." - No sh*t.

 

[SRE]

Last time I ran a query past MCS they told me to check with NICEIC - it was about the barn SAP and they've said that SAP 2009 was ok for that. Other colleagues I work with in the Midlands have had a response from MCS saying that 2009 is ok. I'm waiting for MCS to come back to me so I'll lt you see what they send when it comes through.

It's obvious that the right hand doesn't know what the left hand is doing! As if the job isn't hard enough...

This week I've discovered that:

Commercial pv is taxable
Vat is 20% on commercial
Scottish installations need a building warranty
Debate about SAP continues ...

 

[dansk]

Its in the MIS document for 2005 SAP - so i agree with BiggsSolar and i will continue to use that untill further notice - just be carefull thats all.

 

[SRE]

Will do ...

 

[HotSpot]

This is SAPPING my will to live

 

[SolarCity]

Getting the estimated yield figures as accurate as possible should be up there with THE most fundamental issues concerning MCS companies. That the issue is clouded in uncertainty between three organisations that we all pay handsomely for is an absolute joke. Ultimately, the customer loses out and they are the party that these organisations are supposed to be helping.

 

[TedM]

I don't see that this is anything to get too exercised about.

The only difference I see between the two is that the solar radiation figures in SAP2009 are about 3% higher than the SAP2005 ones.

Also I fail to understand why MCS do not mandate the use of SBEM to calculate the figures for commercial buildings. (SAP itself is only supposed to be used for residential dwellings and SBEM is the equivalent for commercial.) If someone is putting up a new building then the predicted pv figures that have been calculated by the architects/designers should be the same as they get from the pv installer.

http://www.2010ncm.bre.co.uk/filelibrary/SBEM_Technical_Manual_v4.0.a_09Jun10.pdf - pv calculation is shown on p94.

The main difference is that solar radiation has to be determined for the specific locality - rather than the SAP approach of using an 'average' figure for the whole of the UK.

 

[gr7]

"The 2009 edition of the Standard Assessment Procedure (SAP 2009) applies from October 2010"

BRE: Standard Assessment Procedure (SAP 2009)

 

[SRE]

Quick update - I spoke to MCS this morning. The PV standards are currently being reviewed but at this moment in time still require installers to complete SAP 2005 assessments for each property. Obviously this can't be done for barns etc in which case SAP 2009 can be used. There is a possibility that the standard may change from SAP 2005 to SAP 2009 but it hasn't yet. Unsurprising the guy at the end of the phone didn't understand either of the versions! He did back up everything he said with - but if NIC are doing your assessment and they have said that SAP 2009 is ok then it's them who will be doing your assessment and you should stick to their standards.

Is anyone else confused!?

 

[SolarCity]

Yes, very confused.

Regarding SAP for barns - we only need SAP for working out yield, so what difference does it make if it's on a barn?

 

[SRE]

Well we're working out SAP measuring windows, doors, insulation and heating - none of which youcan do for a barn - it's open to the elements.

 

[SolarCity]

But isn't this outside the jurisdiction of the MCS? The MCS isn't concerned with windows, doors nor insulation is it?

 

[TedM]

It's worth noting that there is a difference in the MCS standards between pv and solar thermal.

For pv SAP is required for both domestic and commercial buildings.

For solar thermal SAP is only required for domestic, and 'proprietary software' can be used for commercial:

"For non-domestic installations, a performance calculation using proprietary software is
permitted. This information should be communicated with the client at or before the point
that the contract is awarded." MCS MIS 3001 p13