Decentralizing electricity generation in Cuba : Implementation of a microgrid in the sugar mil lCarlos Baliño

Abstract: Cuba has a long history of different dependencies and is a country facing many energy challenges, and therefore seeks to diversify its energy sources and reduce its reliance on fossil fuels. The purpose of this degree project is therefore to conceptualize a microgrid based on renewable energy sources for local energy sustainability at the lowest cost possible. For this purpose, the sugar mill Carlos Baliño and its surrounding community, in Villa Clara, Cuba is used for a case study. The currently existing electricity generation at Carlos Baliño is tied to the steam needed to run the sugar production process, which is generated with a back-pressure steam engine. This thesis evaluates the possibility to extend the system including a condensing extraction steam turbine connected to a new generator, solar PV, and wind power by developing and comparing three scenarios for the future. The BASE scenario is the business as-usual case including no changes, the PLAN scenario is based on the plans of installing a 1 MW solar PV power plants, and the APT scenario includes all possible technologies to be part of the system. For all scenarios, the different microgrid configuration were evaluated based on the following key performance indicators; CAPEX, NPV, IRR and DPP of the microgrid, share of electricity supplied from the grid and lastly the emission reduction rate compared to the current system in Carlos Baliño. In addition to the technical, economic, and social perspective, the results are evaluated in relation to the national context and goals. Evolution of microgrids is significant to develop more sustainable power systems. The key advantages of this microgrid solution include reduced greenhouse gas emissions, increased energy independence, and improved resilience in the electricity supply. By utilizing bagasse and renewable energy sources like solar PV and wind, Cuba can reduce its dependence on imported fossil fuels, leading to lower carbon emissions and contributing to global climate change mitigation efforts. Moreover, the integration of bagasse-based cogeneration plants enhances the country's energy resilience by diversifying the energy mix and reducing vulnerability to external energy shocks. The distributed nature of microgrids enables local communities to generate their own clean energy, fostering self-sufficiency and socioeconomic empowerment. The results show negative NPV for the BASE and PLAN scenarios. When including a Condensing Extraction Steam Turbine generator, the electricity supplied from the grid decreases from 30 to 11% for the BASE scenario and even more for the PLAN. Additionally, for the PLAN scenario, the 1 MW solar PV investment in isolation generates a positive NPV of 2.67 million USD indicating a good investment even though the whole system shows infeasibility and should increase the solar PV installation size to become profitable. Lastly, for the APT scenario, the NPV is 59.8 million USD, with an IRR of 11% and payback time of 7 years showing a good investment. However, with a high CAPEX of 41.3 million USD. The emission reduction rate is as high as 92%. Furthermore, a sensitivity analysis is performed to address the uncertainty in different cost parameters affecting the results of the study. And the result shows that the system NPV is most sensitive to the change in cost in bagasse fuel price. In conclusion, the integrated microgrid solution with solar PV and bagasse represents a sustainable and resilient energy option for Carlos Baliño and Cuba in general. By capitalizing on its solar potential and utilizing bagasse as a local biomass resource, Cuba can achieve a greener and more reliable energy system while promoting rural development and reducing carbon footprint. This solution can serve as a blueprint for other regions in Cuba and the Caribbean with similar energy challenges seeking to transition to renewable energy and achieve energy security.