prEN IEC 62862-1-5:2023

SLOVENSKI STANDARD
01-julij-2023
Sončne termoelektrarne - 1-5. del: Preskus postopkov merjenja učinkovitosti za
sončne termoelektrarne
Solar thermal electric plants - Part 1-5: Performance code test for solar thermal electric
plants
Centrales électriques solaires thermiques - Partie 1-5 : Essai du code de performance
pour les centrales électriques thermosolaires
Ta slovenski standard je istoveten z: prEN IEC 62862-1-5:2023
ICS:
27.160 Sončna energija Solar energy engineering
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

117/177/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 62862-1-5 ED1
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2023-05-12 2023-08-04
SUPERSEDES DOCUMENTS:
117/170/CD, 117/176/CC
IEC TC 117 : SOLAR THERMAL ELECTRIC PLANTS
SECRETARIAT: SECRETARY:
Spain Ms Lourdes González Martínez
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

Other TC/SCs are requested to indicate their interest, if any, in this
CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
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is drawn to the fact that this Committee Draft for Vote (CDV) is
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TITLE:
Solar thermal electric plants – Part 1-5: Performance code test for solar thermal electric plants

PROPOSED STABILITY DATE: 2028
NOTE FROM TC/SC OFFICERS:
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without
permission in writing from IEC.

– 2 – IEC CDV 62862-1-5 © IEC 2023
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Symbols . 8
5 Performance reference . 9
5.1 Requirements . 9
5.2 Simulation model . 10
6 General test guidelines . 11
6.1 Test procedure. 11
6.2 Guidelines for each type of test . 12
6.2.1 Short-duration tests . 13
6.2.2 Long-duration tests . 13
6.3 Test boundary . 14
7 Instruments and methods of measurement . 14
7.1 General requirements . 14
7.2 Required measurements . 15
7.2.1 Direct solar irradiance . 15
7.2.2 Heat transfer fluid flow rate . 16
7.2.3 Temperatures . 16
7.2.4 Wind speed . 17
7.2.5 Relative Humidity . 17
7.2.6 Atmospheric Pressure. 17
7.2.7 Net plant electricity generation: delivered electricity to the grid minus
received electricity from the grid . 18
7.2.8 Electricity consumption at auxiliary transformer . 18
8 Performance calculations . 18
8.1 Available solar radiation energy . 18
8.2 Plant electricity consumption. 19
8.3 Net electricity . 20
8.4 Non-solar energy . 20
8.5 Net plant efficiency . 21
8.6 Recording and processing data . 21
8.7 Results presentation . 22
8.8 Acceptance test procedure. 22
9 Performance test report . 23
9.1 Executive summary . 24
9.2 Introduction . 24
9.3 Instrumentation . 24
9.4 Calculations and results . 24
9.5 Conclusions . 24
9.6 Annexes . 24
Annex A (normative) Uncertainty Calculation . 26

IEC CDV 62862-1-5 © IEC 2023 – 3 –
A.1 Purpose and assumptions . 26
A.2 Equations for calculating net plant efficiency . 26
A.3 Considerations for calculating uncertainties . 27
A.4 Basic equations for calculating uncertainties . 28
A.5 Calculating uncertainties . 28
A.5.1 Introduction . 28
A.5.2 Type B uncertainty of the direct solar irradiance . 29
A.5.3 Type B uncertainty of the electrical power . 30
A.5.4 Type B uncertainty of the mass flow rate of heat transfer fluid in the
auxiliary heater . 30
A.5.5 Type B uncertainty of the enthalpy difference of heat transfer fluid in the

auxiliary heater . 31
A.6 Alternative method for calculating the uncertainty of net plant efficiency . 32
A.7 Calculation of type B standard uncertainty when redundant instruments are
used . 32
A.7.1 Type B standard uncertainty of temperatures measured with two
redundant sensors . 33
A.7.2 Type B standard uncertainty of direct solar irradiance. 33
Annex B (informative) Example of uncertainty of net efficiency calculated following the
procedure in clause A.5 . 34
Annex C (informative) Example of uncertainty of net efficiency calculated following the

alternative procedure described in clause A.6 . 40

Figure 1 – Energy flows in a Solar Thermal Power Plant . 6
Figure 2 – Required simulation model inputs and outputs . 11
Figure 3 – Generic test boundary and energy flows. 14
Figure 4 – Typical electrical connections in a power plant . 18
Figure 5 – Examples of acceptance criteria. Comparison of the measured value (M)
against the reference value (RV) with uncertainty bands . 23

Table 1 – Symbols and units . 8
Table 2 – Example of a test main results table . 22
Table 3 – Levels of confidence and associated coverage factors (Normal distribution) . 22

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SOLAR THERMAL ELECTRIC PLANTS –
Part 1-5: Performance test code for solar thermal electric plants

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