IEC 62670-2:2015

IEC 62670-2 ®
Edition 1.0 2015-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Photovoltaic concentrators (CPV) – Performance testing –
Part 2: Energy measurement
Concentrateurs photovoltaïques (CPV) – Essai de performances –
Partie 2: Mesure de l'énergie
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IEC 62670-2 ®
Edition 1.0 2015-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Photovoltaic concentrators (CPV) – Performance testing –

Part 2: Energy measurement
Concentrateurs photovoltaïques (CPV) – Essai de performances –

Partie 2: Mesure de l'énergie
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 27.160 ISBN 978-2-8322-2627-8

– 2 – IEC 62670-2:2015 © IEC 2015
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Description of the method . 9
5 Selection of subset under test . 10
6 Operation, maintenance and cleaning . 10
7 Downtimes and unavailability . 11
8 Parasitic energy. 11
9 Data acquisition . 11
9.1 General requirements . 11
9.1.1 Data acquisition system (DAS) . 11
9.1.2 Sampling interval . 12
9.2 Mandatory measurements . 13
9.2.1 General . 13
9.2.2 Direct normal irradiance. 13
9.2.3 Global plane of array irradiance . 13
9.2.4 Ambient air temperature . 14
9.2.5 Wind speed . 14
9.2.6 Electrical power or energy . 14
9.2.7 Cold source temperature (actively cooled systems only) . 14
10 Data post-processing . 14
10.1 Calculation of energy from integrated power values . 14
10.2 Calculation of energy from discrete power values . 15
10.3 Calculation of the DNI time series . 15
10.4 Calculation of the active AC or DC energy . 17
11 Calculation of the performance ratio . 18
11.1 General . 18
11.2 AC performance ratio . 18
11.3 DC performance ratio . 19
12 Derived parameters . 20
13 Report . 20
Annex A (informative) Some suggested ways to filter data in order to identify incorrect
data . 22
Annex B (informative) Best practices for power plant energy measurement . 23
Annex C (normative) Optionally derived parameters. 24
C.1 General . 24
C.2 Energy Production Rate (EPR) . 24
C.3 Capacity Factor (CF) . 24

Figure 1 – Nomenclature of angles used in Formula (2) . 17

Table 1 – Steps of the energy measurement procedure . 10
Table 2 – Mandatory measurements. . 13

– 4 – IEC 62670-2:2015 © IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PHOTOVOLTAIC CONCENTRATORS (CPV) –
PERFORMANCE TESTING –
Part 2: Energy measurement
FOREWORD
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