Currently I am on Sabbatical as the James M. Flaherty Visiting Professor hosted by the Trottier Institute for Sustainability in Engineering Design (TISED), at McGill University, Montreal. TISED, as its title indicates, is broadly interested in sustainability and recently hosted a workshop on Quebec’s resource recovery potential. I attended this workshop out of interest and was pleasantly surprised that I could make a valid contribution despite having little or no expertise in e.g. anaerobic digesters, water treatment or mineral recovery from sludge, but because one of the key questions that arose was how the energy recovered from waste is best integrated into the Quebec energy system.
This question is a classic example of Energy Systems Integration (ESI), an area that is becoming increasingly important globally as society tries to transition to a sustainable energy system. ESI is the process of coordinating energy systems across multiple pathways and/or geographical scales to deliver reliable, cost-effective energy services with minimal impact on the environment[1].
Here the ESI question is how best, across the multiple criteria of reliability, cost and emissions, to integrate a fuel (bio gas) that is harvested from distributed waste resources into an energy system. The options include direct integration into the regional gas network for use later, or conversion directly at the point of harvesting into the regional electricity grid and/or a local heat system. In this specific example within Quebec, a quick analysis indicates that conversion to heat and/or electricity is almost certainly not cost effective due to the existence of very cheap hydro generated electricity and consequently a large electric heating load. The best option for this biogas in Quebec may therefore be in the transport system, highlighting another important aspect of ESI i.e. the integration with other large infrastructures like transport, water (a source of the waste) and enabled by the data and communications system.
The transport option may also be unattractive, due to the infrastructure investment required and the comparison with alternative solutions to the transport challenges. Therefore one option that must also be considered is to not convert the waste to energy. This does not mean that waste to energy is not a viable proposition in general, but rather that it may not be viable in Quebec, highlighting the system specific dimension to the best ESI solutions. For example, waste to energy may be attractive in another system like Denmark or indeed in Quebec under a different regulatory and policy environment, highlighting that ESI initiatives are not only driven by physical and purely economic drivers, but are also sensitive to policy and regulatory environments.
UVIG as an organisation has championed the integration of variable renewable energy sources into electricity grids. However, as the penetration levels increase, we find that there are periods of extreme surplus. The economics dictates that we consider storing this energy for reuse later, or we use it in areas that we traditional did not use electricity, for example heating, transport etc. This electrification of the energy system and increased integration is recognised by UVIG and others as an important global trend and I expect that more ESI type thinking will start to become a larger and more significant part of the variable renewable integration dialogue in the future.
Mark O’Malley
Director, International Institute for Energy Systems Integration
Brian Beecher says
Great work and timely discussion to have around this matter. My question to you is; what data do you have built around the efficiency or lacking thereof performance regarding the commercial and industrial installation of geothermal district heating systems? Who would you suggest that I get in contact regarding my interest with research and development data with geothermal district heating systems.