Prof. Daniel Favrat
Technological and methodological approaches of advanced urban energy networks
Daniel Favrat is professor emeritus at Ecole Polytechnique Federale de Lausanne (EPFL) and former director of EPFL Energy Center. Previously he was director of the Industrial Energy Systems Laboratory of EPFL for 25 years. He is vice-chairman of the energy committee of the World Federation of Engineering Organizations and member of the editorial board of Energy. He is also a member of the Swiss Academy of Engineering Sciences and of the French National Academy of Technologies. He is also president of the international foundation for films on energy (fifel.ch), cofounder of ExerGo.ch and a fellow of Presans.com
Following the Paris protocol and the most recent IPCC warnings increasingly ambitious objectives towards a carbon free society are being proposed. Urban areas have a high energy density demand but also offer major opportunities of synergy between providers and users of energy. To tackle this potential requires not only improved technological schemes but also proper methodologies to differentiate between the various options.
This contribution intends to highlight both new district and cooling network options of what we call 5th generation with either water or CO2 as transport fluids within 1 to 3 pipes networks and an updated exergy efficiency characterization based on the division of the problems into 4 subsystems as proposed earlier. Additional considerations such as the need for a renewable energy ratio as well as practical factors in densely occupied streets of cities will be mentioned. While the main focus will be on providing heating and cooling in cities with buildings having different retrofit status and therefore different temperature requirements, approaches to smaller villages will also be briefly discussed.
Longer term perspective aiming at exploiting the synergies with other networks like the natural gas networks equipped with SOFC fuel cell systems with CO2 recovery or local power to gas and gas to power energy storage will also be explained. Theoretical comparison will be shown of different alternatives for a given city area with a mixed category of users (residential, supermarkets, servers, office) with a reference to earlier work including the account for some of the major uncertainties on the economic comparison. One concept with the use of CO2 as a transport fluid will be particularly highlighted with additional contributions to the building extinction capabilities with limited drawbacks in case of fire.
District and cooling networks, exergy, heat pump, cogeneration, power to gas, gas to power