Renergen Limited, an investment holding company, engages in the alternative and renewable energy businesses in South Africa and sub-Saharan Africa. It operates through Tetra4 and Cryovation segments. The company explores for, develops, and sells liquefied natural gas and helium gas. It also develops Cryo-Vacc technology, which enables the transportation of vaccines and biologics at low temperature without any electrical power. Renergen Limited was founded in 2005 and is based in Sandton, South Africa.