NEWS & EVENTS renewable energy system will be very expensive because of the need to achieve the dependability and resiliency demanded by consumers of their energy supplies - especially electrical and thermal energy. This article will introduce you to a new nuclear technology that promises to help achieve a zero-emission energy system at lower cost than a 100% variable renewable system. Variable renewables will be part of the energy mix in order to achieve a minimum cost clean energy system because nuclear power is not well suited economically to supplyshort term peak demand. Before we jump into the technology discussion, it is helpful to review the energy needs of an industrial society like Ontario's. That will help us identify the types of energy we require and how best to transition those to zero emission sources. OUR ENERGY USE Ontario's energy use in 2017 (the most recent year complete data is available) and greenhouse gas (GHG) emissions are summarized in Figure 1A and 1B below. The data has been restructured from its published format to identify electricity demand separately from the other sectors of the economy: Figure 1 A: Energy used by sector It is important to realize that electricity is much more expensive to supply than heat. Most industrialized societies require a significant amount of heat. Producing and then converting electrical energy to heat is usually more expensive on a total cost basis than simply providing heat directly to consumers who need heat. Zero Emission Technologies If we are serious about achieving a net zero energy system for the whole economy by 2050 then we need to make use of all the available technologies in their most advantageous roles and avoid those roles for each technology that do not meet consumers' dependability and resiliency requirements. Here in Ontario, we have access to the following zero emission technologies: * Hydroelectric (limited in Ontario, affected by climate change) * Solar (variable, affected by climate change and limited in winter) * Wind (variable, affected by climate change and limited in summer) * Bio-fuels (limited in Ontario) * Nuclear (several challenges need to be overcome to gain wide public acceptance) circ땠 33% Industrial circ