BS EN 61853-1:2011 PV (PV) module performance testing and energy rating. Irradiance and temperature performance measurements and power rating

What is BS EN 61853-1 - Irradiance and temperature performance measurements of PV module about? 
BS EN 61853 is an International Standard series that discusses photovoltaic (PV) modules. It establishes IEC requirements for evaluating PV module performance based on power (watts), energy (watt-hours) and performance ratio (PR). It is written to be applicable to all PV technologies including non-linear devices, but the methodology does not take into account transient behaviour such as light induced changes and/or thermal annealing. 
BS EN 61853-1 is the first part of the BS EN 61853 series that describes requirements for evaluating PV module performance in terms of power (watts) rating over a range of irradiances and temperatures 
The object of BS EN 61853-1 is to define a testing and rating system, which provides the PV module power (watts) at maximum power operation for a set of defined conditions. A second purpose is to provide a full set of characterization parameters for the module under various values of irradiance and temperature. This set of measurements is required in order to perform the module energy rating described in IEC 61853-3. 
Who is BS EN 61853-1 - Irradiance and temperature performance measurements of PV module for? 
BS EN 61853-1 on irradiance and temperature performance measurements of PV module is useful for: 
PV module manufacturers  
PV power system manufacturers 
Photoelectric device manufacturers 
Solar energy engineering industry 
Product designers 
Quality assurance and testing personnel 
Why should you use BS EN 61853-1 - Irradiance and temperature performance measurements of PV module? 
Accurate determination of photovoltaic module performance requires precise measurement of  irradiance and temperature performance measurements and power rating. 
BS EN 61853-1 assists you with the power rating conditions, the procedure for irradiance and temperature performance measurements, and rating of power. 
With BS EN 61853-1-compliant performance measurements you can demonstrate the impact of irradiance and temperature on module performance as the power delivery of photovoltaic devices is a direct function of module temperature and incident irradiance level.