Techno-economic assessment of photovoltaic (PV) and building integrated photovoltaic/thermal (BIPV/T) system retrofits in the Canadian housing stock

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 substan

Techno-economic assessment of solar assisted heat pump system retrofit in the Canadian housing stock

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

Techno-economic feasibility evaluation of air to water heat pump retrofit in the Canadian housing stock

This study was conducted to assess the techno-economic feasibility of converting the Canadian housing stock (CHS) into net/near zero energy buildings by introducing and integrating high efficient and renewable/alternative energy technologies in new construction and existing houses. Performance assessment of energy retrofit and renewable/alternative energy technologies in existing houses in regional and national scale is necessary to devise feasible strategies and incentive measures. The Canadian Hybrid Residential End-Use Energy and GHG Emissions model (CHREM) that utilizes a bottom-up modeling approach is used to investigate the techno-economic feasibility of air to water heat pump retrofit in the Canadian housing stock. The proposed energy retrofit includes an air to water heat pump, auxiliary boiler, thermal storage tank, hydronic heat delivery and domestic hot water (DHW) heating. Energy savings, GHG emission changes and economic feasibility of the air source heat pump retrofit are considered in this study. Results show that there is a potential to reduce 36% of energy consumption and 23% of GHG emissions of the CHS if all eligible houses undertake the retrofit. Economic analysis indicates that the feasibility of air to water heat pump systems is strongly affected by the current status of primary energy use for electricity generation and space and DHW heating as well as energy prices and economic conditions. Legislation, economic incentives and education for homeowners are necessary to enhance the penetration level of air to water heat pump retrofits in the CHS

Techno-economic study of solar combisystem retrofit in the Canadian housing stock

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

Techno-economic evaluation of internal combustion engine based cogeneration system retrofits in Canadian houses - A preliminary study

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

Development and analysis of strategies to facilitate the conversion of Canadian houses into net zero energy buildings

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

Stirling engine based cogeneration system retrofit impact on the energy requirement and greenhouse gas emissions of the canadian housing stock

Energy end-use and greenhouse gas (GHG) emission impact of retrofitting Stirling engine based cogeneration systems in existing Canadian houses is studied using the Canadian Hybrid Residential End-Use Energy and GHG Emissions Model (CHREM). CHREM includes close to 17,000 unique house files that are statistically representative of the Canadian housing stock (CHS). The cogeneration system performance was evaluated using a high resolution integrated building performance simulation software. It is assumed that the Stirling engine cogeneration system is retrofitted into all houses that currently use a central space heating system and have a suitable basement or crawl space. A high efficiency auxiliary boiler is included to supply heat when cogeneration unit capacity is not sufficient to meet the heating load. The GHG emission intensity factor associated with marginal electricity generation in each province is used to estimate the annual GHG emissions reduction due to the cogeneration system retrofit. The results show that cogeneration retrofit would yield substantial energy savings and GHG emission reductions in the CHS

Preliminary study for solar combisystem potential in Canadian houses

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 fr