Fossil energy, especially petroleum, has become the main source of human energy, but the
energy crisis is increasingly felt. Indonesia, dependent on 47% of its energy from
petroleum, faces running out of reserves within 12 years. As a solution, biogas from organic
waste, such as fisheries waste, is being developed as an alternative energy source that has
the potential to reduce environmental pollution and provide a renewable energy source in
the future. This research aims to examine the potential of fish offal waste and cow feces
treatment as raw materials in making biogas as alternative energy. The research methods
used include analysis of the influence of sugar composition and fermentation time on
biogas formation, treatment of cow feces on biogas products, as well as analysis of flame
tests of biogas products. The results of this research show that the highest biogas yield
(193.755 grams) from fermenting fish innards was obtained during a fermentation period
of 16 days with the addition of 100 grams of sugar. Treatment of unfermented cow feces
in making biogas from fish innards results in higher biogas yield compared to treatment of
fermented cow feces. So it can be concluded that fish offal waste and treated cow feces
have potential as raw materials for making biogas. The correct fermentation time and
addition of sugar have a significant effect on biogas production from fish offal waste. Apart
from that, the treatment of cow feces also affects the results of biogas production, where
unfermented cow feces produces higher levels of biogas. Suggestions for further research
are to carry out further studies regarding the optimization of the biogas production process
from fish offal waste and cow feces.