Energy and Water system integration in the urban environment

The transition from a fossil to a renewable energy system presents challenges in ensuring reliable and affordable energy supply. This dissertation addresses these challenges by proposing an integrated system approach to designing a renewable energy and water system on the neighborhood level. The concept, known as Power-to-H3, involves converting local solar and wind energy to hydrogen and heat, utilizing rainwater for various purposes, and incorporating multiple energy carriers (electricity, heat and hydrogen). A techno-economic simulation multi-energy model is developed and applied to assess to what extend the concept is clean, reliable, and affordable in delivering the neighborhood system services energy, transport and water (Chapter 2 & 3). The study explores different system integration scenarios, highlighting the benefits of combining power-to-heat, seasonal heat storage, and power-to-hydrogen methods to create a more balanced system that can be cheaper than all-electric solutions (Chapter 3). Additionally, the research proves the value of including seasonal storage in MES modelling by investigating in more detail the coupling of a multi-energy system model with a numerical hydro-thermal model for accurate modelling of high-temperature aquifer thermal energy storage systems (Chapter 4). Moreover, the recovery of waste heat from electrolysis and its potential for CO2 savings is assessed, which shows how the efficiency of electrolysis increases to 90% when waste heat is utilized (Chapter 5). Finally, an experimental study examines the integration of energy and water systems in a building, demonstrating the cooling effects of green roofs with rainwater storage on solar panels with an expected 4.4% higher PV output (Chapter 6). Overall, this dissertation provides insights into designing reliable, affordable, and clean energy and water systems at the neighborhood level, particularly in North-West European contexts.