Institute for High-technologies and Systems, Slovenia
Title: Exergy as measure of sustainability of energy system
P. Novak was professor and Chief Laboratory for HVAC and Solar Energy all at Fac. of Mech. Eng. Ljubjana, Dean of Faculty, Dean of High School for Technologies and Systems, Novo mesto and Director of the Institute for High-technologies and Systems. Last activities in EEA, Past Vice-chairman of Scientific Committee at European Environmental Agency, Copenhagen, 20012-2016 Scientific Activities: Heat and mass transfer in buildings and building equipment, solar energy, environment and climate change. For his activities become: Honorary Member of IIR, 2003, Fellow and Life Member of ASHRAE 1999; Honorary Member of REHVA, SITHOK and SLOSE. Publications and Mentorships: Author and co-author of more than 430, scientific papers, studies, reviews, owner of 10 patents, mentor of 20 PhD students, more than 25 Master students and more than 300 engineering students. Publication information’s are available, from 1980 on www.COBISS.si, Slovenian cooperative online bibliographic system under No. 00956.
Do we need energy or exergy? Amount of exergy in energy carriers is very different and prices include value of quantity and not the quality of energy. Exergy is measure for quality of energy, because the only part of energy available to do work is exergy. For different purposes we need energy with different amount of exergy: for heating and cooling energy mixture between small amount of the exergy and large part anergy is needed. Transition to sustainable energy system, without GHG emissions, based on RE, open the questions how to evaluate exergy from solar energy. Solar energy in all form (irradiation, water flows, wind, and biomass) consists from nearly 100% of exergy. Solar energy is for free, conversion systems are not. To exploit at maximum the present infrastructure there is common agreement that we need sustainable energy system with four main energy carriers: electricity, gaseous, liquid and solid fuels.
Our vision is the new Sustainable Energy System (SES) based on the biomass carbon recycling using solar and planetary energy for electricity and hydrogen production. SES is based on the existing infrastructure and known chemical processes. With regards to availability of renewable energy resources (RES) it is unrestricted in comparison to present fossil fuels use. The proposed SES consists of the three main energy carriers: electricity, synthetic methane (CH4) and synthetic methanol (CH3OH).