The two main problems in Semarang Regency are the uncontrollable spreading of water hyacinth which endangered the existence of Lake Rawa Pening and also the very high usage rate of unsustainable energies for cooking purpose, especially in rural areas. The goal of this project is to build a more efficient small scale water hyacinth biogas plant for a selected users near Lake Rawa Pening as a way to reduce the CO2 Emission and the energy expense by using free renewable energy and also to reduce the spread of water hyacinth on Lake Rawa Pening by using it as a biogas substrate. Due to lack of experience on fermenting water hyacinth and also limited technology, our partner (Yayasan Rumah Energi) is unable to determine the potential of water hyacinth as a biogas substrate for their plants. Because of this condition the Indonesian government didn’t show great interest on Yayasan Rumah Energi’s project. In this case a research on biogas production from water hyacinth and an optimization of the existing plant system (slurry mixing using submersible pump) have to be done at the Rottenburg University from November 2016 to March 2017 and the project realization will be done on April/May 2017. The selected owner and users will be trained to operate the plant properly and to take care of it. Furthermore we will inform the community and the Indonesian government about the importance of this project in particular through presentations so that more similar projects can be implemented in the near future.