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In recent years, several researchers have studied the potential use of ammonia (NH3) as an energy vector, focused on the techno-economic advantages and challenges for full global deployment. The use of ammonia as fuel is seen as a strategy to support decarbonization; however, to confirm the sustainability of the shift to ammonia as fuel in thermal engines, a study of the environmental profile is needed. This paper aims to assess the environmental life cycle impacts of ammonia-based electricity generated in a combined heat and power cycle for different ammonia production pathways. A cradle-to-gate assessment was developed for both ammonia production and ammonia-based electricity generation. The results show that electrolysis-based ammonia from renewable and nuclear energy have a better profile in terms of global warming potential (0.09–0.70 t CO2-eq/t NH3), fossil depletion potential (3.62–213.56 kg oil-eq/t NH3), and ozone depletion potential (0.001–0.082 g CFC-11-eq/t NH3). In addition, surplus heat for district or industrial applications offsets some of the environmental burden, such as a more than 29% reduction in carbon footprint. In general, ammonia-based combined heat and power production presents a favorable environmental profile, for example, the carbon footprint ranges from −0.480 to 0.003 kg CO2-eq/kWh.

Cooking is one of the most important final household uses of energy. In Ecuador, the main energy carrier for this use is liquefied petroleum gas (LPG), which normally is supplied in bottles. LPG is imported and heavily subsidized for household consumption. The Government has promoted the use of electric induction stoves provided the hydropower generation capacity in Ecuador is projected to grow. Sustainability issues should be considered when changes in energy systems are analyzed. Life cycle assessment (LCA) is a methodological framework that can be used to quantify the environmental performance of any product or service, including energy systems. LCA can be used to quantify a range of environmental impact categories including Climate Change. The life cycle greenhouse gas emissions of a product or service are also known as carbon footprint. The objective of this study is to quantify the change in the carbon footprint of the household cooking system from the current based on LPG to the proposed based on electricity, and the cumulative energy demand (CED) for cooking with both technologies, using the LCA methodology, in order to provide a basis for the development of policies to reach the maximum mitigation of greenhouse gases (GHG). Several scenarios that consider different electricity generation mixes, cooking efficiency and emissions profile are studied. The functional unit for comparison was defined as “1 effective MJ”, which is 1 MJ transferred to the food during cooking. System boundaries for the assessment included resources extraction, processing, energy carrier supply, cooking and manufacturing of the stove. The results depend highly on the carbon footprint of the electricity system and, in a lesser extent, on the stove efficiency. Main results indicate that a carbon footprint mitigation occurs when changing the conventional LPG to a highly hydropower based cooking system, and that a higher life cycle energy efficiency is obtained when a high stove efficiency is considered. However, a greater carbon footprint may occur when cooking is performed using fossil derived power, which is a possible case when cooking is performed during peak demand of electricity.