History of - and Comments On

SKN_N0211R0

History of - and comments on

the “PV/T issue”

2013-16-01, jen

Content

Introduction

The history

SKN decision at 7th meeting (September 2009):

Decision D5.M7 – Solar Keymark Certification of PV/T collectors

SKN decision at 10th meeting (March 2011):

Decision D7.M10 – Solar Keymark certification of PV/T collectors

October 2011: CCB does not approve to include PV/T collectors as decided by SKN above

12th SKN meeting March 2012

November 2012 - First (internal) proposal from the PV/T working group

December 2012 - Second proposal from the PV/T working group - this was send out for voting by correspondence (first round)

January 2013 - Third proposal from the PV/T working group - this was send out for voting by correspondence (second round) - document SKN_0208R1

Comments from Andreas (08-01-2013)

Comments from Mark (15-01-2013)

Comments from Korbinian (16-01-2013)

Introduction

The proposal given in SKN_N0208R1 for including PVT collectorsin the Solar Keymark Scheme Rules has raised a discussion on this issue - and on some basic Keymark issues too.

In this document the history of the issue and comments on SKN N0208R1 from:

Andreas Bohren /SPF
Mark Witt /TÜV US
Korbinian Kramer /ISE

are given in order to have the material for the discussion in one place

The history

SKN decision at 7th meeting (September 2009):

Decision D5.M7 – Solar Keymark Certification of PV/T collectors

The participants present decided that Solar Keymark Certification of PV/T collectors as a solar thermal product is possible provided the measurements of the thermal performance are performed with and without electricity production. For the electrical load applied for the electricity production a MPP Tracker shall be used.

In the Solar Keymark data sheet the thermal performance with and without electricity production shall be presented (see note below).

Note: (Practical comment by the Secretary) In present version of the Solar Keymarkcollector data sheet there is no room for two values for the thermal performanceparameters. Until further notice the two sets of values for a PV/T collector are given inthe following way:

Values for PV/T collector without electricity production: To be given in the normalway in the data sheet.
Values for PV/T collector with electricity production: To be given with the following explanation in the comments field of the data shee: The thermal performance of the collector is reduced if electricity is producedsimultaneously. A test was performed with simultaneous electricity production; results from this test show the following performance parameters: n0a: d.ddd; a1a: d.ddd w/(m²k); a2a: d.dddd w/(m²k²); tstg: ddd °c.

This decision was taken with one abstention.

SKN decision at 10th meeting (March 2011):

Decision D7.M10 – Solar Keymark certification of PV/T collectors

The participants present decided that Solar Keymark certification of PV/T collectors as a solar thermal product is possible provided the measurements of the thermal performance are performed with electrical production under MPP conditions.

In addition an optional thermal performance determination without electrical production (open circuit for PV-Module) is possible.

For the electrical load applied for the electrical production an appropriate solution for the MPP tracking shall be used

This decision was taken with two negative votes and eight abstentions.

Note: This decision replaces decision D5.M7 – Solar Keymark certification of PV/T collectors

Scheme rules 13.

October 2011: CCB does not approve to include PV/T collectors as decided by SKN above

In CCB document N592 they argue for their position:

SUBJECT

Solar Keymark for PVT collectors

BACKGROUND

PVT collectors combine a PV (photovoltaic) collector with a solar thermal collector, forming one device that converts solar radiation into electricity and heat simultaneously.

Solar thermal collectors fall in the domain of CEN. PV collectors fall in the domain of CENELEC.

Solar thermal collectors conforming to EN 12975 are covered by the current Solar Keymark scheme rules of CEN, developed by the Solar Keymark Network (SKN).

SKN has decided to certify PVT collectors as solar collectors under the Solar Keymark scheme rules.

This is currently not possible because EN 12975 does not cover PVT collectors.

However, in May 2011 a draft for a new EN 12975 which includes PVT collectors has been sent to the TC312 Secretariat for enquiry. In the scope of this draft, reference to PVT collectors is made as follows:

It is also applicable to thermal-electrical hybrid collectors, so called PVT collectors; however it does not cover electrical safety or other specific properties related to the PV part of these collectors.

The CCB Secretariat consulted in May 2011 three certification bodies who are active in the domains of CEN as well as CENELEC: AENOR, CERTIF and IMQ.

To note in this respect that DIN CERTCO and ICIM should also have been consulted; DIN CERTCO is part of the TÜV Rheinland Group, which is very active in the PV area.

In general, the view is that certification of PVT collectors should include PV related safety and performance features as laid down respectively in the EN 61730 series (Photovoltaic (PV) module safety qualification) and EN 61215 (Crystalline silicon terrestrial photovoltaic (PV) modules).

This has also been discussed at a meeting of the Solar Keymark empowered certification bodies on 21 June 2011, in which DIN CERTCO and ICIM also participated.

PROPOSAL

The reputation of the Keymark may be seriously harmed when a PVT collector which is carrying the Solar Keymark proofs to be electrically unsafe or unreliable and of a low quality. That is why only CE marking of the PV modules under the LVD is not sufficient; it is only a manufacturer’s declaration and there are not Notified Bodies involved.

Therefore, electrical safety and performance of the PV modules has to be certified by an accredited certification body on the basis of the relevant European standards.

Only if this condition is fulfilled, a Solar Keymark empowered certification body can issue a Keymark licence for the PVT collector on the basis of the (future) EN 12975.

Unfortunately, this means indeed that the manufacturer/supplier needs two marks: the Keymark for the solar thermal collector, and a mark covering electrical safety and performance of the PV modules.

The above proposal may therefore not be the most elegant solution, but it is the easiest and most practical way to ensure that Solar Keymark certified PVT collectors are quality products and (electrically) safe.

In the data sheet of the Solar Keymark certified PVT collectors on the website, information about the certificate for the PV modules will be provided.

12th SKN meeting March 2012

The situation that the PV/T proposal was not approved by CCB was discussed at the 11th SKN meeting; it was decided to establish a PV/T Work Group, as seen from the minutes of the meeting:

Since the discussion showed that the subject is quite complex it was not possible to elaborate during this meeting a consensus. Hence a working group consisting of the following persons was established.

Uli Fritsche (Chair), Joakim Bynström, Sören Scholz, Korbinian Kramer, Marco Trionfetti, Giovanni Bellenda. Carsten Lampe, Joao Santos.

The task of this working group is to elaborate a modified version of the Solar Keymark scheme rules including Solar Keymarking of PV/T collectors as a basis for a resolution at the next Solar Keymark Network meeting

November 2012 - First (internal) proposal from the PV/T working group

Not included here as it was made for internal discussion in the working group.

December 2012 - Second proposal from the PV/T working group - this was send out for voting by correspondence (first round)

Proposal: SOLAR KEYMARK-Scheme Rules amendments for PVT certification

Revision 2.1 issued 2012-12-12 by Ulrich Fritzsche (TÜV Rheinland)

Co-authors: Joakim Byström (Absolicon), Daniel Eggert (ISFH), Korbinian Kramer (Fraunhofer ISE),Sören Scholz (DINCERTCO), Mark Witt (TÜV Rheinland PTL)

Due to the fact, that there is no standard fully covering PVT Hybrid collectors or a standard mentioning PVT’s (neither within EN 12975-1 or -2 nor within IEC 61215; 61646; 62108; 61730), there’s a need of additional requirements within Solar KEYMARK Scheme Rules to ensure a harmonized procedure within the third parties involved in the Solar KEYMARK certification.

PVT Hybrid collectors can get a Solar KEYMARK certification if the following requirements are fulfilled:

-Full certification of the PVT Hybrid collector/module (not only the PV-module) by an accredited and IECEE accepted certification body CB based on reports given by an IECEE accepted test laboratory CBTL(see IECEE certification for PV via according to

EN 61215 “Crystalline silicon terrestrial photovoltaic (PV) modules - Design qualification and type approval (IEC 61215)” ;
EN 61646 “Thin-film terrestrial photovoltaic (PV) modules - Design qualification and type approval” (IEC 61646)
EN 62108 “Concentrator photovoltaic (CPV) modules and assemblies – Design qualificationand type approval (IEC 62108)“ and
EN 61730-1“Photovoltaic (PV) module safety qualification - Part 1: Requirements for construction” (IEC 61730)”
EN 61730-2“Photovoltaic (PV) module safety qualification - Requirements for testing” (IEC 61730)”
IEC 62688 “Concentrator photovoltaic (CPV) module and assembly safety qualification” (after official publication as standard)

-Consideration of temperature test results (stagnation temperature) within IEC test procedure
(important at least for covered and concentrating PVT’s)

-Full EN 12975 test of the PVT Hybrid according to SK Scheme Rulesby a SOLAR KEYMARK-recognized test laboratory

-Reference of IEC (or IECEE) certification within Test-Report, Solar KEYMARK Data Sheet, and Solar KEYMARK certificate (similar to the solar thermal system certificate according to EN 12976 with the reference to the collector certificate according to EN 12975).

-Calculation of Power output thermal and electrical including interaction of thermal on electrical performance according ScenoCalc (if applicable). If it is not applicable, it need to be clearly stated, that the recent data sheet is only an interim solution until the calculation is implemented in ScenoCalc. Furthermore, the electrical operation mode the figures for the thermal energy prediction based on need to be stated.

For PVT Hybrids where the PV module has been modified after original manufacture to operate in hybrid, such as through adhesive or mechanical bond between absorber and module, the following requirements need to be fulfilled:

-Full certification of the PV module accredited and IECEE accepted certification body CB based on reports given by an IECEE accepted test laboratory CBTL (see IECEE certification for PV via according to

EN 61215 “Crystalline silicon terrestrial photovoltaic (PV) modules - Design qualification and type approval (IEC 61215)” ;
EN 61646 “Thin-film terrestrial photovoltaic (PV) modules - Design qualification and type approval” (IEC 61646)
EN 62108 “Concentrator photovoltaic (CPV) modules and assemblies – Design qualificationand type approval (IEC 62108)“ and
EN 61730-1“Photovoltaic (PV) module safety qualification - Part 1: Requirements for construction” (IEC 61730)”
EN 61730-2“Photovoltaic (PV) module safety qualification - Requirements for testing” (IEC 61730)”
IEC 62688 “Concentrator photovoltaic (CPV) module and assembly safety qualification” (after official publication as standard)

-Verification, that the assembly of the PVT did not adversely affect PV components and the PV module safety and durability through evaluation based on the IEC 61215, 61646, 62108 and 61730 retest guidelines

CTL decision sheet DSH0647A:2010 “Retest Guidelines for IEC 61215 and IEC 61646”
CTL decision sheet DSH0770:2010 “Retest Guidelines for IEC 61730-1/-2”
CTL decision sheet DSH0778:2010 “Retesting guideline for changes in CPV cell package technology”

(by an accredited and IECEE accepted test laboratory CBTLfor the above listed standards).

-Full EN 12975-2 test of the PVT Hybrid according to SK Scheme Rulesby a Solar KEYMARK- recognized test laboratory

-Reference of IEC certification within Solar KEYMARK-Report ,Data Sheet, and Solar KEYMARK certificate (similar to the solar thermal system certificate according to EN 12976 with the reference to the collector certificate according to EN 12975)

-Calculation of Power output thermal and electrical including interaction of thermal on electrical performance according ScenoCalc (if applicable). If it is not applicable, it need to be clearly stated, that the recent data sheet is only an interim solution until the calculation is implemented in ScenoCalc.Furthermore, the electrical operation mode the figures for the thermal energy prediction based on need to be stated.

Only a few Solar KEYMARK recognized testing laboratories are also accredited for IEC testing. The verification of electrical safety or PV durability aspects shall only be performed by IECEE accepted CBTL’s with scopes including the above mentioned IEC standards. SK certification bodies shall only do the document examination, that all required certificates and verification reports are available.

January 2013 - Third proposal from the PV/T working group - this was send out for voting by correspondence (second round) - document SKN_0208R1

Proposal: SOLAR KEYMARK-Scheme Rules amendments for PVT certification

Revision 3.0 issued 2013-01-07 by Ulrich Fritzsche (TÜV Rheinland)

Co-authors: Joakim Byström (Absolicon), Daniel Eggert (ISFH), Korbinian Kramer (Fraunhofer ISE),Sören Scholz (DINCERTCO), Mark Witt (TÜV Rheinland PTL), Stephan Fischer (ITW)

Due to the fact, that there is no standard fully covering photovoltaic and thermal PVT Hybrid collectors or a standard mentioning PVT’s (neither within EN 12975-1 or -2 nor within IEC 61215; 61646; 62108; 61730), there’s a need of additional requirements within Solar KEYMARK Scheme Rules to ensure a harmonized procedure within the third parties involved in the Solar KEYMARK certification.

All required PV related tests and verification procedures need to be performed by an ISO 17025 accredited and IECEE accepted CBtest laboratory CBTL and all certificates shall be issued by an EN 45011 accredited and IECEE accepted certification body CB. (see IECEE certification for PV via

PVT Hybrid collectors can get a Solar KEYMARK certification if the following requirements are fulfilled:

- A:Full certification of the PVT Hybrid collector/module (not only the PV-module) according to

EN 61215 “Crystalline silicon terrestrial photovoltaic (PV) modules - Design qualification and type approval (IEC 61215)” ;
EN 61646 “Thin-film terrestrial photovoltaic (PV) modules - Design qualification and type approval” (IEC 61646)
EN 62108 “Concentrator photovoltaic (CPV) modules and assemblies – Design qualificationand type approval (IEC 62108)“ and
EN 61730-1“Photovoltaic (PV) module safety qualification - Part 1: Requirements for construction” (IEC 61730)”
EN 61730-2“Photovoltaic (PV) module safety qualification - Requirements for testing” (IEC 61730)”
IEC 62688 “Concentrator photovoltaic (CPV) module and assembly safety qualification” (after official publication as standard)

-B:For PVT Hybrids where the PV module has only been “modified” after original manufacture to operate in hybrid, such as through adhesive or mechanical bond between absorber and module, it is possible to use the original PV-module certificate (according to the above listed standards), if a verification procedure confirms, that the assembly of the PVT did not adversely affect PV components and the PV module safety and durability through evaluation based on the IEC 61215, 61646, 62108 and 61730 retest guidelines

CTL decision sheet DSH0647A:2010 “Retest Guidelines for IEC 61215 and IEC°61646”
CTL decision sheet DSH0770:2010 “Retest Guidelines for IEC 61730-1/-2”
CTL decision sheet DSH0778:2010 “Retesting guideline for changes in CPV cell package technology”

-Consideration of temperature test results (under stagnation conditions) within IEC 61730 test procedure as well as requirements for all polymers as defined in IEC 61730-1
Remark: Most PV-module test standards are only considering standard PV modules without any thermal insulation or additional cover. For the definition of thefinal test procedure, the resulting raised stagnation temperature need to be taken into account . In some cases for example, the climate chamber temperature need to be adapted.

-Full EN 12975 test of the PVT Hybrid according to SK Scheme Rulesby a SOLAR KEYMARK-recognized test laboratory

-Thermal performance detection shall be performed with the PV-module working in MPP mode as main working conditions. Additional performance tests with PV-module working in open or short circuit mode are possible. The reference values for the data sheet will always be the ones detected with MPP mode for PV.

-Reference of IEC (or IECEE) certification within Test-Report, Solar KEYMARK Data Sheet, and Solar KEYMARK certificate (similar to the solar thermal system certificate according to EN 12976 with reference to the collector certificate according to EN 12975).

-Calculation of output power both thermal and electrical, including interaction of thermal on electrical performance according to ScenoCalc (if applicable).If it is not applicable, it need to be clearly stated, that the recent data sheet is only an interim solution until the calculation is implemented in ScenoCalc. The electrical operation mode used for thermal performance test and energy prediction need to be stated.

Comments from Andreas (08-01-2013)

Dear Friends of PVT collectors, dear SKNetwork

Although I might be one of the triggers for the current action I have to vote with a “NO” from SPF. I appreciate the work of the working group, thank you. However, thinking about the proposal it became clear to me that I don’t agree with the current approach, mainly for formal reasons.

Please let me explain the NO from SPF:

I think there are some major and fundamental errors in reasoning:

1.)On the Keymark webpage (not SOLAR Keymark, but more fundamental, CEN Keymark: ) we read “The Keymark is a voluntary European certification mark, demonstrating that a product is in conformity with the European Standard….” This is the fundament of all Keymarks. The intention of the Keymark is hence NOT to make sure that a product fulfils general quality or performance requirements. The requirement is that the product is in conformity with a given standard. That’s it. Any additional requirement for the PV have nothing to do with the EN12975 and there is no Keymark for the PV standards. The EN12975 covers the aspects of the solar thermal collector not less and not more. I fully understand the concerns of CCB but from a formal point of view I think that CCB is somehow off the track.

2.)It is not appropriate to base the Keymark on other (non-Keymark) certification schemes. The requirement for an EN12975 Keymark as a basis for the EN12976 Keymark is something completely different because here the two certificates are based on the same fundamental regulations (Keymark). Basing the Solar Keymark on other certification schemes will induce difficulties as these regulations can be changed anytime by other committees. What if these changes are in conflict with the Keymark regulations?