Translations:Simplified weather and solar resource evaluation/2/en

Temperature and insolation largely determine the energy production of PV source. Temperature affects the performance of every component of an off-grid PV system, in almost all cases negatively. When designing an off-grid PV system the conditions under which a system will be operating will be factored into the design to make sure that the system can still deliver power when necessary even under the worst-case weather and solar resource conditions.

Information about the weather and solar resource for a location is most accurate when it is obtained from a nearby weather station that has many years of recorded data that can be analyzed at the level of days. Weather and solar resource can vary quite significantly from year to year and in the case of off-grid PV system design the months with the worst weather are the most important. Weather and solar resource data readily available on the internet, although there are print copies of this information for some locations. There is rarely local weather and solar resource data for remote locations where off-grid PV systems tend to be installed, which means that information must be used from the nearest site – which can be quite far away – or be obtained from an organization that provides estimates based upon computer models. There is no single definitive source for information that covers the entire globe and is available in many languages, although there are some resources that are close. These will be explored below.