We describe a polygeneration system that can run on neat plant oils, such as Jatropha and Pongamia, or standard diesel fuel. A prototype has been constructed using a compression ignition engine of 9.9 kW shaft output. It consumes 3 L/h of fuel and will produce 40 kg/h of ice by means of an adsorption refrigerator powered from the engine jacket heat. Steaming of rice, deep and shallow frying, and other types of food preparation heated by the exhaust gas have been demonstrated. In addition, the feasibility of producing distilled water by means of multiple-effect distillation powered by the engine waste heat is shown. Overall plant efficiency and potential savings in greenhouse gas emissions are discussed.

The energy-water nexus is a concept widely established but rarely applied to product and, in particular, to food and beverage products, which have a great influence on greenhouse gases emissions. The proposed method considers the main nexus aspects in addition to other relevant aspects such as climate change, which is deeply linked with energy and water systems, and assessing process as well as product. In this framework, this study develops an integrated index (IWECN) that combines life cycle assessment (LCA) and linear programming (LP) to assess energetic, water and climate systems, enabling the identification of those products with minors energetic and water intensity and climate change effects and helping to the decision-making process and to the development of eco-innovation measures. In this case, the product assessed was one bottle (70 cl) of gin and two main hotspots were identified: the production of the glass bottle and the energy requirements of the distillation stage. Based on that, several eco-innovation strategies were proposed: the use of photovoltaic solar energy as energy source and the substitution of the glass bottle by a plastic one and by a tetra brick. The nexus results indicated that the use of solar photovoltaic energy and plastic as bottle material was the best alternative decreasing 58% the IWECN value of the production of one bottle of gin. The sensitivity analysis presented a strong preference for photovoltaic solar energy in comparison with electric power and for the reduction of the glass bottle weight or its substitution by a plastic bottle. The use of the IWECN index is extendable to any product with the aim of facilitating the decision-making process in the development of more sustainable products to introduce them in new green markets.

Rural electrification is constrained by grid extension infrastructural cost, isolated low rural populations, lack of anchor loads, and repayment potential of villagers while decentralized renewable energy power is constrained by high capital cost, low reliability, and non-workable business models. Solar thermal energy can produce electricity, heating, cooling, water, and fuel and has the potential for storage for livelihood applications. Hence solar thermal energy-based cogeneration and polygeneration systems have the potential for intervention in rural livelihoods with a focus on the energy-land–water-food nexus. However, standalone solar thermal systems are capital intensive and shadowed by photovoltaics. In the current work, an island in the Indian Ocean is considered for the study, and a solar thermal energy-based hybrid polygeneration system is designed with end products such as electricity, heating, cooling for food storage, and desalinating to get pure water. The turbine, VAM, pasteurization unit, and membrane distillation unit are the considered components in the present analysis. The thermodynamic properties of the key components of the polygeneration system are identified and the energy and entropy balance of the system is done. The levelised cost of production of polygeneration outputs for 25-year operational life with an accelerated depreciation of 30% of the capital cost, over 8 years is carried out. It is found that the electricity and water pricing are INR 14.71 and INR 14.01 per unit which are not attractive. Normalization is done by adjusting the price of other polygeneration outputs namely refrigeration, hot water, and pasteurizing to make the electricity and water pricing feasible to achieve an IRR of 12.99% and payback of 9 years at a 5% annual escalation. The social cost saved with the benefit of polygeneration outputs is cumulated considering value addition in the supply chain to save agricultural produce and milk, which otherwise would have spoiled. The annual carbon emissions that are curtailed with solar thermal polygeneration outputs are cumulated and found to be 434 tonnes of carbon. The social cost and environmental cost due to carbon are considered as an incentive in the cost economic economics of polygeneration system and it is found that the IRR and payback can be improved to 17.98% and 6.2 years respectively. The work recommends policy interventions to promote decentralized solar thermal polygeneration systems for impact on rural livelihoods with a focus on the energy-water-food nexus.