The testing and characterization of solar thermal systems and components have been investigated from the inception of the IEA Solar Heating & Cooling Programme. Performance test procedures and characterization equations were originally developed for typical solar collector types under well-defined standard test conditions. In addition, short-term tests were developed to predict the long-term durability of standard collectors and systems. Presently, national and international test laboratories in many IEA participant countries use these test procedures and characterization equations in order to determine a solar thermal product's performance and compliance with required safety and reliability standards. While there is a solid common foundation for most test procedures, certification bodies for Europe, North America, Australia, China and Europe and the laboratories that they work with have diverged in how tests are implemented in some areas, and the introduction of new products have introduced new challenges that are not always addressed in the same way.

Partly because of these differences, it is not possible for a manufacturer to have a system certified for one region or country and have the test results that support that certification transfer to another region or country. Testing and certification must be repeated in each region or country, slowing product introduction in new markets and adding to costs. While this task cannot ensure that certification bodies will harmonize their testing and certification efforts, it will work on resolving issues and inconsistencies involved in the standards for testing and the implementation of those standards. This will create a technical foundation for certification bodies to consider accepting tests and certifications across borders in order to lower barriers to solar heating and cooling products competing in global markets. In addition the task will explore approaches to testing and characterization of systems and collectors that relate to user thermal comfort and environmental impacts, issues that are increasingly important but where a uniform assessment methodology is lacking.