The RETScreen software Suite is a unique decision support tool developed with the contribution of numerous experts from government, industry, and academia. The software, provided free-of-charge, can be used worldwide to evaluate the energy production and savings, costs, emission reductions, financial viability and risk for various types of Renewable-energy and Energy-efficient Tech**logies (RETs). The software (available in multiple languages) also includes product, project, benchmark, hydrology and climate databases, a detailed user manual, and a case study based college/university-level training course, including an engineering e-textbook.