The Solar Ratings & Certification Organization (ICC-SRCC) is an independent ratings organization for solar systems and is widely recognized as the official standard in the field. The ICC-SRCC rates thermal performance of individual solar collectors as well as complete functional systems. Many state and utility rebate programs require ICC-SRCC ratings for products to qualify and system performance can be compared to others in the field using the product directory.

The Florida Solar Energy Center (FSEC) is the primary testing lab that performs ICC-SRCC ratings. In addition to testing solar thermal systems, FSEC also has its own rating system that is widely adopted in both Florida and the Caribbean. FSEC is also engaged in a wide range of energy-efficient and renewable technologies ranging from photovoltaics to reflective roofs.

The Uniform Plumbing Code, which is maintained by IAPMO governs the way plumbing systems may be constructed in the Western United States. Solar systems are often covered under IAPMO regulations, and an independent Uniform Solar Energy Code has been developed explicitly for the design and installation of solar thermal systems. SunEarth solar thermal collectors are listed as compliant with IAPMO codes.

ASHRAE is the leading trade organization for HVAC (Heating Ventilation & Air-Conditioning) professionals in the world. For anything from residences to skyscrapers, ASHRAE has developed standards for it and you’ll find equipment suppliers serving that broad range at their annual trade fair. ASHRAE is also responsible for standard 93-1986, which is the standard used by the ICC-SRCC and FSEC in testing solar thermal collectors.

A leading industry organization for mechanical and thermal systems engineers, ASME is a good clearinghouse of information and produces the ASME Journal of Solar Energy, which includes research on solar thermal systems and heat transfer.

The National Renewable Energy Laboratory (NREL) is the central government lab responsible for renewable energy development. In addition to physical testing and development of renewable systems, NREL publishes some of the most comprehensive weather data sets used for estimating system performance. Typical Meteorological Year weather data known as TMY2 is often used in the solar thermal field to size solar thermal systems.

The Solar Energy Laboratory at the University of Wisconsin is one of the oldest labs in the nation dedicated to the study of solar thermal systems. Many industry standard modeling tools such as F-chart and TRNSYS were developed at the Solar Energy Laboratory & their website contains information about these tools.

A joint program of the Department of Energy and the Environmental Protection Agency.  Energy Star has developed eligibility criteria for high efficiency water heaters, including solar water heating systems.  The criteria are predicated on achieving a solar franction 0.50, or greater.  

DSIRE is a comprehensive source of information on state, local, utility and federal incentives and policies that promote renewable energy and energy efficiency. Established in 1995 and funded by the U.S. Department of Energy, DSIRE is an ongoing project of the North Carolina Solar Center and the Interstate Renewable Energy Council.

IREC provides a good database of state-by-state solar licensing requirements and regulations.

SEI provides certified technical training for solar water heating and PV.