The utilization of biomass energy is important from both an energetic and environmental point of view. Saudi Arabia has a considerable amount of biomass waste that can be converted to renewable energy using different technologies. This study evaluated and analyzed the quantity and energy potential of biomass waste, Greenhouse gases (GHG) emissions, and cost estimation of power generation using different conversion techniques. The results showed that the annual biomass waste in Saudi Arabia could reach approximately 31.50 million tons, which can generate 15 TWh of electricity. Municipal solid waste (MSW) is the largest contribution to the total waste and total power generation potential, which is approximately 70% and 74% of the total, respectively. Although incineration of MSW has the highest cost requirements, it has the highest power generation potential compared with the other studied techniques. However, the anaerobic digestion of other biomass types has the advantages of low costs and GHG emissions and generates considerable energy. The findings of this study can support decision-makers in developing sustainability strategies using eco-friendly and economical technologies for efficient power generation from biomass wastes.