Biomass is an increasingly important renewable energy resource, in part because it offers a way to utilize “waste” organic materials to produce electricity and heat using commercial and mature technology. Because of concerns with the depletion of fossil fuels and the adverse environmental impacts associated with their use, biomass is recognized to reduce greenhouse gases for sections of organic materials presently disposable in the environment. This study presents and reviews research regarding biomass power and cogeneration plants. Key considerations are a general description of a biomass power plant, key conversion technologies utilized in power generation, and details on plant performance and environmental effect. This paper specifically focuses on various possible conversion processes: direct combustion for power generation; gasification, including plasma gasification, for electricity or heat generation; anaerobic digestion and bio-hydrogen production, with use as a fuel; and an overview of biorefining. The study looks at both urban and rural applications and notes the applicability of biomass for waste management. A detailed examination of greenhouse gas reduction for biomass is discussed, focusing on carbon neutrality. Implications related to emissions air, water, and land is outlined. Available information in the published literature regarding the performance and suitability of each method and future research directions were evaluated in order to gain further insights on the potential of using biomass as a future method for meeting our energy needs in a sustainable fashion.