• Energy Research

Abstract Canada has numerous climatic and geographical regions and the Canadian housing stock (CHS) is diversified in terms of vintage, geometry, construction materials, envelope, occupancy, energy sources and heating, ventilation and air conditioning system and equipment. Therefore, strategies to achieve net zero energy (NZE) status with the current stock of houses need to be devised considering the unique characteristics of the housing stock, the economic conditions and energy mix available in each region. Identifying and assessing pathways for converting existing houses to NZE buildings at the housing stock level is a complex and multifaceted problem and requires extensive analysis on the impact of energy efficiency and renewable/alternative energy technology retrofits on the energy use and GHG emissions of households. A techno-economic analysis of retrofitting renewable/alternative energy technologies in the CHS to reduce energy consumption and GHG emissions was conducted to develop strategies to achieve or approach NZE status for Canadian houses. The results indicate that substantial energy savings and GHG emission reductions are techno-economically feasible for the CHS through careful selection of retrofit options. While achieving large scale conversion of existing houses to NZEB is not feasible, approaching NZE status is a realistic goal for a large percentage of Canadian houses.

Abstract Techno-economic impact of retrofitting houses in the Canadian housing stock with PV and BIPV/T systems is evaluated using the Canadian Hybrid End-use Energy and Emission Model. Houses with south, south-east and south-west facing roofs are considered eligible for the retrofit since solar irradiation is maximum on south facing surfaces in the northern hemisphere. The PV system is used to produce electricity and supply the electrical demand of the house, with the excess electricity sold to the grid in a net-metering arrangement. The BIPV/T system produces electricity as well as thermal energy to supply the electrical as well as the thermal demands for space and domestic hot water heating. The PV system consists of PV panels installed on the available roof surface while the BIPV/T system adds a heat pump, thermal storage tank, auxiliary heater, domestic hot water heating equipment and hydronic heat delivery system, and replaces the existing heating system in eligible houses. The study predicts the energy savings, GHG emission reductions and tolerable capital costs for regions across Canada. Results indicate that the PV system retrofit yields 3% energy savings and 5% GHG emission reduction, while the BIPV/T system yields 18% energy savings and 17% GHG emission reduction in the Canadian housing stock. While the annual electricity use slightly increases, the fossil fuel use of the eligible houses substantially decreases due to BIPV/T system retrofit.

Techno-economic feasibility of retrofitting solar combisystems to houses in the Canadian housing stock (CHS) is investigated using the Canadian Hybrid Residential End-Use Energy and Emissions Model (CHREM). Solar combisystem architecture and sizing is based on the systems and guidelines provided by the International Energy Agency (IEA) Solar Heating and Cooling (SHC) Programme Task 26. Houses with sufficient roof area facing south, south-east or south-west, and a basement or mechanical room to contain solar combisystem components, including the thermal storage tank, auxiliary boiler and pumps, are considered eligible to receive the retrofit. A hydronic heat delivery system is used to supply heat to the thermal zones. Solar collector area is sized to match the nominal capacity of the existing heating system in each house. Reductions in energy consumption and greenhouse gas (GHG) emissions are evaluated. Results show that close to 40% of houses in the CHS are eligible for solar combisystem retrofit, and if all eligible houses are retrofitted, the annual energy consumption and GHG emissions of the CHS would be reduced by about 19%. The tolerable capital cost varies significantly amongst provinces, and governmental subsidies or incentive programs may be required to promote solar combisystems in some provinces.

Abstract The residential sector is responsible for 11.7% of global greenhouse gas (GHG) emissions. Space and domestic hot water (DHW) heating accounts for about 80% of the energy consumption of households in cold-climate regions. This study investigates the status of the housing stock in a set of cold-climate countries (i.e., Northern Europe and Canada) with the goal of identifying the barriers to achieving net zero emission (NZEm) status in the residential sector. Several parameters are analyzed, including vintage, energy mixture for onsite heating and offsite electricity generation, energy use, and GHG emissions intensities. Potential scenarios of energy supply and their impact on energy consumption and GHG emissions of the residential sector are discussed. Results show that the existing houses are not energy efficient, and it will be a challenge to reduce the GHG emissions of the residential sector. The energy outlooks indicate that the carbon intensity of grid electricity would not be zero due to reliance on fossil fuels. Therefore, an existing household could not achieve NZEm status by solely using grid electricity. Deep energy retrofits, renewable energy technologies, and reducing the carbon intensity of energy sources are measures to be implemented to achieve NZEm status for the residential sector.

Abstract The techno-economic feasibility of retrofitting existing Canadian houses with solar assisted heat pump (SAHP) is investigated. The SAHP architecture is adopted from previous studies conducted for the Canadian climate. The system utilizes two thermal storage tanks to store excess solar energy for use later in the day. The control strategy is defined in order to prioritise the use of solar energy for space and domestic hot water heating purposes. Due to economic and technical constraints a series of eligibility criteria are introduced for a house to qualify for the retrofit. A model was built in ESP-r and the retrofit was introduced into all eligible houses in the Canadian Hybrid Residential End-Use Energy and GHG Emissions model. Simulations were conducted for an entire year to estimate the annual energy savings, and GHG emission reductions. Results show that the SAHP system performance is strongly affected by climatic conditions, auxiliary energy sources and fuel mixture for electricity generation. Energy consumption and GHG emission of the Canadian housing stock can be reduced by about 20% if all eligible houses receive the SAHP system retrofit. Economic analysis indicates that the incentive measures will likely be necessary to promote the SAHP system in the Canadian residential market.

Abstract This study investigates the greenhouse gas (GHG) emissions from diesel- and liquefied natural gas-fueled (LNG) heavy-duty vehicles (HDVs) in the context of Canada and the province of British Columbia (BC) from 2014 to 2050. HDVs accounted for 18% and 11% of the 2014 GHG emissions from the transportation sector in Canada and BC, respectively. Different scenarios are analyzed using the GHGenius model and recent emissions measurements from LNG HDVs. The low emissions scenario of 1 g C H 4 /k g LNG indicates that LNG HDVs could reduce GHG emissions by 22% and 30% in Canada and BC, respectively. Also, the analysis shows that Canada’s and BC’s well-to-wheels (WTW) methane emissions should be maintained below 13 and 18 g C H 4 /k g LNG to produce less GHG emissions from LNG HDVs than their diesel counterparts. If WTW methane emissions are maintained at the current estimated rate of 26 g C H 4 /k g LNG , replacing diesel with LNG in HDVs would change GHG emissions from +1.7% to +24% for Canada, and from −8% to +16% for BC by 2050. Finally, our study indicates that even methane emissions of 1 g C H 4 /k g LNG would not be enough to decrease GHG emissions of HDVs by 80% below 2005 levels by 2050 as is the target set by the Government of Canada and BC. However, LNG HDVs do reduce nitrogen oxides and particulate matter emissions. Policy makers could support LNG HDVs for immediate reductions of nitrogen oxides and particulate matter, but should support methane emissions measurements and control campaigns, and other alternative fuels to meet the 80% GHG emission reduction target by 2050.

Abstract A preliminary techno-economic evaluation of retrofitting reciprocating internal combustion engine based cogeneration into existing Canadian houses for the purpose of achieving or approaching net-zero energy rating is presented. Primary energy and electricity consumption, associated greenhouse gas emissions and tolerable capital cost are used as indicators. A whole building simulation model was used to simulate the performance of a commonly used cogeneration system architecture with thermal storage in “typical” single storey houses located in Halifax, Montreal, Toronto, Edmonton and Vancouver, representing the five major climatic regions of Canada. The system is assumed to sell excess electricity to the grid at the purchase price. A high efficiency auxiliary boiler is included to supply heat when cogeneration unit capacity is not sufficient to meet the heating load. The effect of thermal storage capacity, interest rate and acceptable payback period on the overall performance was evaluated through a sensitivity analysis. The findings suggest that internal combustion engine based cogeneration provides a promising option to achieve net-zero energy rating for Canadian houses, and therefore more detailed studies focusing on the entire Canadian housing stock are needed.

Solar combisystems that are capable of providing space heating and cooling as well as domestic hot water heating present a promising alternative to conventional systems to achieve net zero energy status in residential buildings. To determine whether or not the performance of such systems would be suitable in the northerly Canadian context, a preliminary study was conducted to evaluate the thermal performance of a solar combisystem with space heating, cooling, domestic hot water heating and thermal storage capability for houses in the four climate regions of Canada (Atlantic, Central, Prairies and Pacific) based on simulations conducted using models developed within the TRNSYS 17.1 energy simulation software. For days without sufficient sunshine, auxiliary heating and cooling systems are included. The operation of the solar combisystem and the auxiliary systems is controlled using a realistic control algorithm. Sensitivity analysis is conducted to determine effects of solar collector area and storage capacity on solar combisystem performance. The results show that solar combisystems can provide a substantial fraction of the space heating, cooling and domestic hot water heating energy requirement of a simple house in all major climatic regions of Canada. As to be expected, climatic conditions have an important impact on solar combisystem performance. The results also show that increasing solar collector area enhances solar fraction, and the solar fraction curve peaks at a specific storage capacity. Based on the favorable results found in this study, it is clear that further and more detailed studies are warranted on solar combisystem applications in Canada. The next step in this work will be a much more detailed evaluation using the Canadian Hybrid Residential Energy End-use and Emissions Model.