RETScreen Expert is a comprehensive Clean Energy Management Software platform which enables professionals and decision-makers to identify and assess the viability of potential energy efficiency, renewable energy and cogeneration projects; and to measure and verify the actual and ongoing energy performance of buildings, factories and power plants around the world. The software is developed by the Government of Canada in collaboration with notable international partners and is used by over 600,000 people in every country and territory of the world. RETScreen is also used as a teaching and research tool by well-over 1,100 universities and colleges worldwide, and is frequently cited in academic literature. RETScreen Expert allows energy professionals and decision-makers to identify, assess and optimize the technical and financial viability of potential clean energy projects. Its decision intelligence software platform also allows managers to measure and verify the actual performance of facilities and helps identify additional energy savings/production opportunities. The software is available in 36 languages and can significantly reduce the financial and time costs associated with identifying and assessing potential renewable energy and energy efficiency projects. RETScreen Expert models a full range of both traditional and non-traditional sources of clean energy as well as conventional energy sources and technologies, including energy efficiency (from large industrial facilities to individual houses), heating and cooling (e.g., biomass, heat pumps, and solar air/water heating), power (including renewables like solar, wind, wave, hydro, geothermal, etc. but also conventional technologies such as gas/steam turbines and reciprocating engines), and combined heat and power (or cogeneration). Integrated into the analytical worksheets are product, project, benchmark, hydrology and climate databases, as well as links to worldwide energy resource maps. RETScreen Expert is managed under the leadership and ongoing financial support of the CanmetENERGY Varennes Research Centre of Natural Resources Canada, a department of the Government of Canada. The core team leverages collaboration with a number of other government and multilateral organisations, with technical support from a large network of experts from industry, government and academia. Principal partners include NASA’s Langley Research Center, the Renewable Energy and Energy Efficiency Partnership (REEEP), Ontario’s Independent Electricity System Operator (IESO), UNEP’s Energy Unit of the Division of Technology, Industry and Economics, the Global Environment Facility (GEF), the World Bank’s Prototype Carbon Fund, and York University’s Sustainable Energy Initiative. RETScreen Expert is available for download completely free-of-charge in Viewer mode. Viewer mode will be sufficient for most energy analysis needs of most users. The full functionality of RETScreen Expert (including the ability to save, print and export files) is available in Professional mode by purchasing a renewable 12-month subscription, currently priced at CAD 869 per subscribing computer (plus applicable taxes) and charged on a cost recovery basis.