The present review provides an overview of the latest research on microalgae production techniques based on carbon instead of light as energy source. The independence of light in mixotrophic and heterotrophic cultivation considerably reduces production costs and space compared to autotrophic production. Hence, this production technique may play a key role to meet future increasing food and feed demands. In order to reach this aim, it is, however, necessary to explore the possibilities of utilizing low-cost carbon sources such as molasses from industrial waste streams. This review provides an overview of worldwide potentially available low-cost carbon sources, potential microalgae species and their chemical composition, available pre-treatment methods for media sterilization and enhanced bioavailability, latest literature on growth of heterotrophic microalgae cultured on new, innovative low cost carbon sources, non-sterile culture approaches, and finally, economic considerations including a future outlook.