Photovoltaic (PV) stand-alone systems Design verification
|Publication Date:||1 October 2004|
|ICS Code (Solar energy engineering):||27.160|
Scope and object
The specifications, test methods and procedures included in this document cover stand-alone photovoltaic (PV) systems. It covers systems containing one or more PV modules, a support structure, storage batterie(s), a charge controller and typical DC loads such as lights, radio, television and refrigerators. AC loads with dedicated inverters are considered as DC loads. The load as specified by the manufacturer is an integral part of the PV system with regards to the design verification.
The focus of the test methods and procedures in this document is limited to system performance evaluation. Individual sub-systems and components may be monitored, but only to evaluate the performance of the overall system.
The results of this test are applicable to the exact components that are tested. Any changes in components or components' specifications require design verification.
NOTE An exception to this rule is the load. Retesting is not necessary, if the nominal power of the load and its characteristics are not altered, always provided that the new loads are also type tested (provided a type test is available) and the operation frequency of the loads electronics controller (if any) do not vary more than 50 % from the new one to the one tested and being replaced. Hence, the replacement of a pure ohmic load by lights using high frequency electronic ballasts would require retesting, but not the change from one electronic lighting product to another one.
The standard is valid for system testing both for outdoors in prevailing conditions and indoors under simulated conditions. The testing conditions are intended to represent the majority of climatic zones for which these systems are designed.
The object of this standard is to verify system design and performance of stand-alone photovoltaic systems. While individual components may be qualified to environmental and safety standards, the assembled system needs further verification, to ensure that the components operate properly together as specified by the system manufacturer. The performance test consists of a check of the functionality, the autonomy and ability to recover after periods of low state-of-charge of the battery, and hence gives reasonable assurance that the system will not fail prematurely.