This technical specification provides guidelines for the parameters to be specified for solar trackers for photovoltaic systems and provides recommendations for measurement techniques. No attempt is made to determine pas s\/fail criteria for trackers.<\/p>\n
The purpose of this test specification is to define the performance characteristics of trackers and describe the methods to calculate and\/or measure critical parameters .<\/p>\n
This specification provides industry-wide definitions and parameters for solar trackers. Each vendor can design, build, and specify the functionality and accuracy with uniform definition. This allows consistency in specifying the requirements for purchasing, compar ing the products from different vendors, and verifying the quality of the products. In addition, this specification will clarify terminology and definitions for trackers and provide examples of measurement techniques.<\/p>\n
This technical specification will be a foundation for other standards to follow , including (but not limited to ) design qualification and reliability.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 4<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | 1 Scope and object 2 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 3 Specifications for solar trackers for PV applications 3.1 Specification template Tables Table 1 \u2013 Tracker specification template <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 4 Tracker definitions and taxonomy 4.1 General 4.2 Payload types 4.2.1 Standard photovoltaic (PV) module trackers <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 4.2.2 Concentrated photovoltaic (CPV) module trackers 4.3 Rotational axes 4.3.1 General 4.3.2 Single axis trackers <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 4.3.3 Dual axis trackers <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | Figures Figure 1 \u2013 \u03b8 = Altitude angle = 0\u00b0 (zenith angle = 90\u00b0) occurs when a vector normal to the module face is pointing to the horizon. Altitude angle = 90\u00b0 (zenith angle = 0\u00b0) occurs when the module is facing the sky <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 4.4 Actuation and control 4.4.1 Architecture 4.4.2 Drive types <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 4.5 Types of tracker control 4.5.1 Passive control 4.5.2 Active control 4.5.3 Backtracking <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 4.6 Structural characteristics 4.6.1 Vertical supports 4.6.2 Foundation types <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 4.6.3 Tracker positions 4.6.4 Stow time 4.7 Energy consumption 4.7.1 Daily energy consumption <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 4.7.2 Stow energy consumption 4.8 External elements and interfaces 4.8.1 Foundation 4.8.2 Foundation interface 4.8.3 Payload 4.8.4 Payload interface 4.8.5 Payload mechanical interface 4.8.6 Payload electrical interface 4.8.7 Grounding interface 4.8.8 Installation effort <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 4.8.9 Control interface 4.9 Internal tolerances 4.9.1 Primary axis tolerance Figure 2 \u2013 Illustration of primary axis tolerance for a polar tracking axis <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 4.9.2 Secondary axis tolerance 4.10 Tracker system elements 4.10.1 Mechanical structure 4.10.2 Tracker controller 4.10.3 Sensors 4.11 Reliability terminology 4.11.1 General 4.11.2 Mean time between failures (MTBF) <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 4.11.3 Mean time between critical failures (MTBCF) 4.11.4 Mean time to repair (MTTR) 4.12 Environmental conditions 4.12.1 Operating temperature range 4.12.2 Survival temperature range 4.12.3 Maximum wind during operation 4.12.4 Maximum wind during stow 4.12.5 Snow load <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 4.13 Functional tests 4.13.1 Static load test 4.13.2 Moment testing 4.13.3 Limit switch operation 4.13.4 Manual operation 5 Tracker accuracy characterization 5.1 Overview 5.2 Pointing error (instantaneous) <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 5.3 Measurement 5.3.1 Overview 5.3.2 Example of experimental method to measure pointing error Figure 3 \u2013 General illustration of pointing error <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 5.3.3 Calibration of pointing error measurement tool 5.4 Calculation of tracker accuracy 5.4.1 Overview Figure 4 \u2013 Two flat parallel plates at a specified distance, one having a pin hole for sunlight to be tracked on specified-diameter circles that ultimately measure 0,1\u00b0, 0,2\u00b0, and 0,3\u00b0 accuracy rings (more if necessary) <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 5.4.2 Data collection 5.4.3 Data binning by wind speed <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 5.4.4 Data filtering 5.4.5 Data quantity 5.4.6 Accuracy calculations <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 6 Mechanical characterization 6.1 General 6.2 Backlash 6.3 Stiffness Table 2 \u2013 Alternate tracking accuracy reporting template <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 7 Reliability testing 7.1 Corrosion 7.2 Component durability 7.3 Extreme conditions tests 8 Additional optional accuracy calculations 8.1 Typical tracking accuracy range <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 8.2 Tracking error histogram 8.3 Percent of available irradiance as a function of pointing error Figure 5 \u2013 Pointing error frequency distribution for the entire test period <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | Figure 6 \u2013 Available irradiance as a function of pointing error Figure 7 \u2013 Available irradiance as a function of pointing error with binning by wind speed <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Photovoltaic systems. Specifications for solar trackers<\/b><\/p>\n |