A sustainable floating dome biogas plants integrated with semi-transparent photovoltaic thermal collectors: Construction, production and economic analysis.

The design and construction of a self-sustained solar photo-voltaic active thermal heating floating dome biogas plant (35 m3) offers an alternative solution for round year biogas production, managing food and agricultural waste, reducing greenhouse gas emissions and minimize pollution. Moreover, this proposed model addresses the challenge of achieving the desired operating temperature (35 ± 2 °C) specially during the cold climatic conditions, which often leads to low gas production and high hydraulic retention time in anaerobic digestion. The integration of solar modules with the biogas digester enables the utilization of thermal energy for slurry heating and electricity for force mode of operation, ultimately enhancing overall energy efficiency. However, to assess the performance of the system, proximate and ultimate analyses as well as a cost-benefit analysis were carried out, considering revenue, and costs associated with construction, operation, and maintenance. The plant produces a significant amount of gas (9–12 m3) and hot water (∼2000 L) replacing approximately one LPG cylinder/2 day as well as organic fertilizer. The economic analysis shows a positive net present value (19.5 lakhs), an internal rate of return (20%), and short discounted payback period (5.7 years). This highlights the economic feasibility of the proposed model and emphasizes the importance of considering economic factors in the design and implementation of sustainable energy solutions. Furthermore, this approach demonstrates the potential for sustainable development and the transition to cleaner and more efficient energy systems by integrating renewable energy generation, waste management, and cost reductions. [Display omitted] • Developed a self-sustained floating dome biogas plant integrated with solar panels. • Integrated system yields round year biogas production, thermal energy, and manure. • Significant (P < 0.05) biogas production was observed during fourth week (19.25%). • Payback period (4.8 yrs), NPV (1.9 million) and IRR (20%) have been recorded. • Due to high retention time, this hybrid system is suitable for colder climates. [ABSTRACT FROM AUTHOR]