Energy Savings Potential in Dual Smart Grid Solutions : Are there synergy effects to be found using a dual smart grid system for heat and electricity?

Abstract: Smart cities and eco-districts will shape a new city landscape in the upcoming years, making renewables the only source of energy. They have the potential to cut greenhouse gas emissions up to 99 %, reaching the ambitious energy and sustainability goals set by Europe and the rest of the world. Double smart grids is a 20th-century concept aiming at connecting the current main energy networks as(electrical and thermal) into a unique mesh. It enables the exchange of energy and new options for storage, flexibility, and reliability. The goal of this study is to show the potential energy savings captured by the implementation of a double smart grid on a district and city level, and to quantify energy savings on a European scale. The first chapter of this work aims to clarify the objective of a smart grid, how it is composed, and why it is called smart. It implies a complete understanding of the history of the two grids, digging on the district heating concept as well as the fundamental of an electrical grid. Moreover, an overview of the major energy needs that usually exist in a district has been presented, to demonstrate what a double smart grid should meet in terms of energy demands. Secondly, an exhaustive analysis has been carried out to point out the main technologies available on the market to meet these energy needs. It focuses on all major renewable heat sources and the upcoming technologies expected to help energy transition in reaching its ambitious goals. The same process is applied for the most mature renewable electricity sources, with a focus on decentralized and decentralized structures. Storage options and flexibility have been added at the list since their integration will drastically reduce energy production. This means that, before producing new energy, it is necessary to better consume the one already produced. It is always true that the greenest kWh is the one ever produced. Lastly, double smart grid synergies have been evaluated through an exhaustive analysis of a smart renewable energy scenario, that includes a complete integration of the double smart grid concept, in the first step, and a triple smart grid concept as full-cycle scenario (including green gas networks). Throughout the entire document, several project examples have been presented to complete the theoretical knowledge with concrete examples developed all over the world. Most of them have been developed by Dalkia Smart Building. The results show the necessity to boost innovation and pilot projects around double smart grids and in general smart energy systems, and it will require impressive efforts from government and private investors.