The National Renewable Energy Laboratory lists an extensive suite of software tools for renewable energy applications.
The Stella Group Ltd has a page of Renewable Energy Modeling Tools, Calculators and Design Guides.
Open EI is a knowledge-sharing online community dedicated to connecting people with the latest information and data on energy resources from around the world.
The Green Tool Wiki includes useful tools for many green and renewable applications.
Mistaya Engineering is a key strategic partner, creators of the Windographer software product. Since 1997, Mistaya Engineering has provided software engineering, documentation, and technical support for HOMER, first for the US National Renewable Energy Laboratory, and now for HOMER Energy.
The Seattle University College of Science and Engineering includes HOMER among its engineering laboratory software applications.
The Solar and Wind Energy Resource Assessment was a five year effort that aimed at developing information tools to stimulate renewable energy development. It covered major areas of thirteen developing countries in Latin America, the Caribbean, Africa and Asia. SWERA's mission was to provide easy access to credible renewable energy data to stimulate investment in, and development of, renewable energy technologies.
COMMEND, the Community for Energy, Environment, and Development, is an initiative of the Stockholm Environment Institute.
InfinitePower.org is provided by the Texas State Energy Conservation Office as a means to accelerate the acceptance of renewable energy resources in Texas.
PermaculturePower is a blog dedicated to supporting efforts to develop permaculture around the world. According to Wikipedia: "Permaculture is an approach to designing human settlements and agricultural systems that are modeled on the relationships found in natural ecologies."