• Energy Research
• CA close
• NL close
• University of Waterloo close

The uptake of energy-efficiency investments in the residential sector is relatively low, despite evidence of short payback periods and numerous co-benefits, including increased home comfort and reduced negative environmental impacts. Common barriers facing homeowners include financial and time constraints, competing priorities, and a lack of adequate information. Home energy audits are an established approach to encourage energy-efficiency investments, with the intention of overcoming the informational barrier by providing personalized energy-efficiency recommendations to homeowners. However, literature suggests that the impacts of these audits are mixed, due to a lack of guidance, procedural information and support from social networks. To fill this gap, the Home Energy Coach program was piloted in Waterloo Region, Ontario, involving government, non-profit, industry and academic stakeholders. Upon receiving an EnerGuide home energy evaluation, homeowners were eligible to participate in free consultation sessions with an Energy Coach to help develop and execute a renovation plan. This thesis documented the coach interactions and renovation progress of 21 program participants through a series of online surveys, with added insight from follow-up interviews with five of these participants. The results indicated that the Energy Coach was helpful in the development of renovation plans of many participants by clarifying the audit recommendations, helping to evaluate options based on each household’s circumstances and guiding participants to additional resources. At the end of the program, 17 out of 18 exit survey respondents had made progress on or completed at least one-energy efficiency measure, with an overall conversion rate of 29 percent from audit recommendation to completed action. The most frequently completed measures were basement/crawl space insulation, draftproofing and window/door replacement, which were also the most frequently recommended measures. This thesis adds to the literature on motivations and ...

The objective of the present investigation has been to combine tracer principles and a hydrolytic microbial activity assay using fluorescein diacetate to monitor changes in microbial biomass within subsurface flow wetland mesocosms. The mesocosm hydrolytic activity was referenced to activated sludge concentrations treating a typical domestic wastewater at full scale. Microbial biomass activity levels within four laboratory wetland mesocosms treating a synthetic domestic wastewater were routinely monitored over a 21-week period of plant growth and rhizosphere development. Although above ground plant mass and tracer dispersion numbers suggested progressive root zone development, plant growth did not result in any measurable enhancement in microbial activity when compared to a mesocosm operating without plants. Dispersion numbers also suggested a reduction in the mass transport kinetics in these planted mesocosms. In-situ biomass monitoring enabled the assessment of a characteristic response in terms of the steady-state food to microorganism (F/M) ratio that was observed in mesocosms receiving both low and high organic loading. Wetland treatment performance is sensitive to the degree to which bed volume is exploited in terms of wastewater flow to regions of bioactivity. The in-situ reactive tracer technique for mesocosm biomass monitoring provided an assessment of the collective substratum and rhizosphere microbial biomass in direct contact with wastewater contaminants. Thus, in-situ biomass monitoring has application in further understanding of plant function and strategies for plant implementation in wetland research and development.

In this paper, a novel algorithm for calculating distribution load flow (DLF) for smart grid is presented. The algorithm can provide a DLF solution in a specific area of interest in the distribution system without the necessity of including all of the distribution system laterals in the DLF problem. The system laterals excluded from the DLF solution are replaced by equivalent loads using a proposed lumping technique. The proposed DLF zooming method thus reduces the size of the DLF problem and hence minimizes the effect of system size on the DLF solution time. The construction of the DLF problem is based on a novel automated recursive process, which enables fast accommodation of changes in the network topology of smart grid. The simulation results validate the accuracy of the proposed DLF zooming algorithm and provide a favorable evaluation of its performance for smart grid operation.

Despite increasing evidence that large northern lakes are rapidly changing due to climate change, descriptive baseline studies of their physicochemical properties are largely lacking, limiting our ability to detect or predict change. This study represents a comprehensive scientific assessment of the limnology of Yukon’s largest lake: Lhù’ààn Mân’ (Kluane Lake), an important waterbody for local and First Nation communities, and key habitat for trout and salmon. Water sample and instrument data generated throughout 2015 describe distinct regions within the lake and their respective seasonal variability. A deep, glacially-influenced southern basin was characterized by cold, turbid, poorly stratified, unproductive, and nutrient-poor conditions; a shallower northwestern region (Tthe Kaala Daagur (Brooks/Little Arm)) was warmer, fully mixed, and more productive; a northeast region (’Ùha K’ènji (Talbot/Big Arm)) was clear and stratified with intermediate depth, temperature, productivity, and nutrient concentrations; and a central region had intermediate physicochemical conditions relative to the other three. This variability demonstrates the need for adequate spatial (within lake) and temporal (between seasons) monitoring of large northern lakes. In 2016, glacier recession within the watershed resulted in diversion of the lake’s primary inflow (‘A’ą̈y Chù’ (Slims River)). Our results, when used together with Indigenous knowledge, form a historical reference that enables assessments of the potential ecological consequences to Lhù’ààn Mân’.

Abstract In polymer electrolyte membrane (PEM) fuel cells, serpentine flow channels are used conventionally for effective water removal. The reactant flows along the flow channel with pressure decrease due to the frictional and minor losses as well as the reactant depletion because of electrochemical reactions in the cells. Because of the short distance between the adjacent flow channels, often in the order of 1 mm or smaller, the pressure gradient between the adjacent flow channels is very large, driving part of reactant to flow through the porous electrode backing layer (or the so-called gas diffusion layer)—this cross-leakage flow between adjacent flow channels in PEM fuel cells has been largely ignored in previous studies. In this study, the effect of cross-flow in an electrode backing layer has been investigated numerically by considering bipolar plates with single-channel serpentine flow field for both the anode and cathode side. It is found that a significant amount of reactant gas flows through the porous electrode structure, due to the pressure difference, and enters the next flow channel, in addition to a portion entering the catalyst layer for reaction. Therefore, mixing occurs between the relatively high concentration reactant stream following the flow channel and the relatively low reactant concentration stream going through the electrode. It is observed that the cross-leakage flow influences the reactant concentration at the interface between the electrode and the catalyst layer, hence the distribution of reaction rate or current density generated. In practice, this cross-leakage flow in the cathode helps drive the liquid water out of the electrode structure for effective water management, partially responsible for the good PEM fuel cell performance using the serpentine flow channels.

A new electrochemical method for the quantitation of bacteria that is rapid, inexpensive, and amenable to miniaturization is reported. Cyclic voltammetry was used to quantitate M. luteus, C. sporogenes, and E. coli JM105 in exponential and stationary phases, following exposure of screen-printed carbon working electrodes (SPCEs) to lysed culture samples. Ferricyanide was used as a probe. The detection limits (3s) were calculated and the dynamic ranges for E. coli (exponential and stationary phases), M. luteus (exponential and stationary phases), and C. sporogenes (exponential phase) lysed by lysozyme were 3 x 10(4) to 5 x 10(6) colony-forming units (CFU) mL(-1), 5 x 10(6) to 2 x 10(8) CFU mL(-1) and 3 x 10(3) to 3 x 10(5) CFU mL(-1), respectively. Good overlap was obtained between the calibration curves when the electrochemical signal was plotted against the dry bacterial weight, or between the protein concentration in the bacterial lysate. In contrast, unlysed bacteria did not change the electrochemical signal of ferricyanide. The results indicate that the reduction of the electrochemical signal in the presence of the lysate is mainly due to the fouling of the electrode by proteins. Similar results were obtained with carbon-paste electrodes although detection limits were better with SPCEs. The method described herein was applied to quantitation of bacteria in a cooling tower water sample.

The smart energy system concept provides an integrated framework for the adoption of renewable energy resources and novel energy technologies, such as distributed battery energy storage systems and electric vehicles. In this effort, large-scale transition towards smart energy systems can significantly reduce the environmental emissions of energy production, while leveraging the compatible operation of numerous distributed grid components to improve upon the energy utility, reliability, and flexibility of existing power grids. Most importantly, transitioning from fossil fuels to renewable energy resources provides environmental benefits within both the building and transportation sectors, which must adapt to address both increasing pressure from international climate change-related policy-making, as well as to meet the increasing power demands of future generations. In the case of building operation, the transition towards future energy systems consequently result in the adoption of decentralized energy networks as well as various distributed energy generation, conversion, and storage technologies. As such, there is significant potential for existing systems to adopt more economic and efficient operating strategies, which may manifest in novel operational modes such as demand-response programs, islanded operation, and optimized energy vector dispatch within local systems. Furthermore, new planning and design considerations can provide economic, environmental, and energy efficiency benefits. While these potential benefits have been justified in existing literature, there is still a strong research need to quantify the impacts of optimal building operation within these criteria, under a smart energy system context. Meanwhile, the transportation sector may benefit from the smart energy network concept by leveraging electric mobility technologies and by transitioning vehicle charging demand onto the grid’s electricity network. In this transition, the emissions associated with fossil fuel consumption are displaced by ...

A mismatch in a photovoltaic array implies differences in the I-V characteristics of the modules forming the array. This can lead to significant energy losses known as mismatch losses. The mismatch and the resulting losses can be reduced by altering the interconnection of the array. This paper proposes an optimal total cross tied interconnection, based on a thorough mathematical formulation that can significantly reduce mismatch losses. The improvement over existing photovoltaic array interconnections has been demonstrated by extensive simulation results.

High geometric aspect ratio, low porosity copper wires were produced by an electroplating technique employing horizontal nonsubmerged jet flow through nozzle anodes, impinging on vertical cathode surfaces. The technique involves an initial deposition of the copper spot whose diameter is controlled by the nozzle diameter. As the deposit tip grew as a circular wire toward the nozzle anode, the copper substrate was continuously displaced away from the nozzle by a computer controlled motor. A typical wire has an aspect ratio of about 90, and a porosity of about 20%.