Climate change and energy security are issues facing municipalities throughout the world. Efficient, resilient, sustainable, community-based energy systems, such as district energy systems (DES), fuelled mostly by renewables, are an important tool for addressing both climate change and energy security at the municipal level. In spite of their benefits, DES are not widely adopted in Canada (CDEA, 2011). This is due to the complex nature of the barriers which project proponents face. This thesis examines the experience of the City of Prince George in adopting and implementing the Downtown DES. Using a case study methodology, data was collected through a review of relevant municipal documents and a series of semi-structured, open-ended interviews. A thematic analysis revealed unexpected barriers related to lack of adequate public consultation and negative perceptions regarding biomass as a fuel for the DES. These `lessons learned' were then developed into recommendations for other municipalities considering DES.

The built environment is responsible for a large portion of total energy use and emissions. A large portion comes from the buildings themselves, but also the transportation system to move people around. As global populations grow, and more people migrate to cities, it is critically important that new city growth is done in the most sustainable manner possible. The typical North American pattern of urban growth is urban sprawl, characterized by single use type zoning, low density, transportation system dominated by personal vehicles, and poor public transit. Urban sprawl has numerous downsides, including poorer energy efficiency in buildings and infrastructure, more congestion and higher emission from vehicles, as well as many negative health effects. This thesis presents the concept of a Mothership, a large, high-density mixed-use building designed to combat urban sprawl and minimize energy use and emissions of the built environment. A mothership is designed to provide all the amenities and housing of a typical suburb for 10,000 people. The analysis in this thesis employ building simulation tools to model various mothership designs and analyse the operational and embodied energy and carbon emissions for each design, and compare it to base cases of more traditional building use types such as single detached homes, and different types of apartment buildings. The effect of high-performance building envelopes and other building materials on operational and embodied energy and emissions are analysed. A multi objective optimization analysis is performed to determine which technologies and combinations of technologies provide the lowest cost solution to meet the mothership’s energy demands while also minimizing emissions. The mothership’s effect on transportation emissions is also investigated. The building’s mixed-use nature allows trips to be satisfied within walking distance in the building. The high concentration of people makes for a good anchor load for public transportation, so the emissions reductions of implementing a bus rapid transit system from the mothership to the central business district is estimated. To reduce transportation emissions further, the effect of an electric car share fleet for mothership residents use is also quantified. The energy system of a mothership is optimized, along with base cases of single detached homes, under numerous scenarios. These scenarios are designed to explore how the energy system changes in an attempt to answer a series of research questions. Some of the measures explored are a high carbon tax, net metering, and emissions limits of net zero, and negative emissions with two different electrical grid carbon intensities. Results showed that a highly insulated, timber framed mothership can achieve very high reductions in energy use and emissions. Overall it showed reductions of 71%, 73%, and 74% in operational energy, embodied energy and embodied carbon respectively, over a baseline case of single detached homes. It was estimated that transportation emissions could be reduced by 58% through the mixed-use development reducing the number of trips and electrically powered transportation vehicles and bus rapid transit. This gives a combined total emissions reduction of 61%. Energy system optimization showed that the mothership design in achieved far lower costs and emissions (4 and 8.7 times lower respectively) than the base case of single detached homes. Of the mothership cases examined, the most expensive case was the one which had a carbon tax, with an annualized cost of $4.3 million. The case with the lowest annualized cost was one with, among other factors, a net zero carbon emissions restriction (annualized cost of $3.08 million. Many of the cases had negative operating costs due to the sale of renewable energy or carbon credits. This illustrates that the integration of renewable energy technologies is not only beneficial for reducing emissions but can also act as an income pathway for energy systems. / Graduate

The aim of this thesis is to develop a holistic approach to the optimal design of energy systems for building clusters or districts. The emerging Albano university campus, which is planned to be a vivid example of sustainable urban development, is used as a case study through collaboration with the property owners, Akademiska Hus and Svenska Bostäder. The design addresses aspects of energy performance, environmental performance, economic performance, and exergy performance of the energy system. A multi-objective optimization approach is applied to minimize objectives such as non-renewable primary energy consumptions, the greenhouse gas emissions, the life cycle cost, and the net exergy deficit. These objectives reflect both practical requirements and research interest. The optimization results are presented in the form of Pareto fronts, through which decision-makers can understand the options and limitations more clearly and ultimately make better and more informed decisions. Sensitivity analyses show that solutions could be sensitive to certain system parameters. To overcome this, a robust design optimization method is also developed and employed to find robust optimal solutions, which are less sensitive to the variation of system parameters. The influence of different preferences for objectives on the selection of optimal solutions is examined. Energy components of the selected solutions under different preference scenarios are analyzed, which illustrates the advantages and disadvantages of certain energy conversion technologies in the pursuit of various objectives. As optimal solutions depend on the system parameters, a parametric analysis is also conducted to investigate how the composition of optimal solutions varies to the changes of certain parameters. In virtue of the Rational Exergy Management Model (REMM), the planned buildings on the Albano campus are further compared to the existing buildings on KTH campus, based on energy and exergy analysis. Four proposed alternative energy supply scenarios as well as the present case are analyzed. REMM shows that the proposed scenarios have better levels of match between supply and demand of exergy and result in lower avoidable CO2 emissions, which promise cleaner energy structures. / <p>QC 20160923</p>

District energy systems are a key component to addressing reductions in green house gases, encouraging compact settlement form and ensuring reliable community energy delivery. System development can also generate local economic benefits like aggregated energy pricing and employment creation. This research focuses on an exploration of Ontario’s planning framework with respect to energy generation and thermal energy distribution, providing broad recommendations to municipalities intended to help facilitate the development of district energy systems. In summary, this research was designed to accomplish the following objectives: 1. To craft a set of transferrable recommendations that will help Ontario municipalities facilitate the development of district energy systems where appropriate. 2. To add to the literature available on district energy system development from a municipal planning perspective. 3. To examine the tools available to planning practitioners to help engage communities and municipalities in planning for local energy generation and delivery. The methodological approach employed for this research is qualitative in nature, relying on an inductive style building from particulars to general themes. The characteristics of a qualitative study are best suited to address the research questions and objectives because community energy planning and land use planning are largely unexplored in conjunction, and this methodology provides a framework to explore where the fields have integrated in practice as well as reveal some of the challenges and potential solutions. Case studies were used to examine the development of two different Ontario district energy systems. Additionally, key informant interviews provide insights from planners, system operators, customers and industry experts to provide a practice based foundation of information to development transferable recommendations. The findings suggest that the development of a district energy system is a very complex process, requiring the expertise of many specialists, and the support from local stakeholders. There are planning implications for the implementation of district energy systems, which require forethought at the beginning of the planning process and opportunities to support community based energy solutions through policy. The adoption of a planning regulatory framework will ensure adequate consideration is given to community energy management in conjunction with land use and urban form. Going forward, accounting for the conservation of energy in land use will be imperative for achieving local, regional and provincial goals associated with infrastructure, the environment, and energy resource management.

District energy systems are a key component to addressing reductions in green house gases, encouraging compact settlement form and ensuring reliable community energy delivery. System development can also generate local economic benefits like aggregated energy pricing and employment creation. This research focuses on an exploration of Ontario’s planning framework with respect to energy generation and thermal energy distribution, providing broad recommendations to municipalities intended to help facilitate the development of district energy systems. In summary, this research was designed to accomplish the following objectives: 1. To craft a set of transferrable recommendations that will help Ontario municipalities facilitate the development of district energy systems where appropriate. 2. To add to the literature available on district energy system development from a municipal planning perspective. 3. To examine the tools available to planning practitioners to help engage communities and municipalities in planning for local energy generation and delivery. The methodological approach employed for this research is qualitative in nature, relying on an inductive style building from particulars to general themes. The characteristics of a qualitative study are best suited to address the research questions and objectives because community energy planning and land use planning are largely unexplored in conjunction, and this methodology provides a framework to explore where the fields have integrated in practice as well as reveal some of the challenges and potential solutions. Case studies were used to examine the development of two different Ontario district energy systems. Additionally, key informant interviews provide insights from planners, system operators, customers and industry experts to provide a practice based foundation of information to development transferable recommendations. The findings suggest that the development of a district energy system is a very complex process, requiring the expertise of many specialists, and the support from local stakeholders. There are planning implications for the implementation of district energy systems, which require forethought at the beginning of the planning process and opportunities to support community based energy solutions through policy. The adoption of a planning regulatory framework will ensure adequate consideration is given to community energy management in conjunction with land use and urban form. Going forward, accounting for the conservation of energy in land use will be imperative for achieving local, regional and provincial goals associated with infrastructure, the environment, and energy resource management.

To achieve the aim of low carbon cities and zero energy districts, it is important to adapt the efficient technologies while maintaining the thermal comfort and sustainable environment. The new challenge in design and building new districts lies in a sustainable and smart way to minimize energy consumption and thus carbon emission. This challenge can be overcome by the use of early-stage energetic and environmental analysis of the planned districts, which can result in sustainable and efficient use of the resources. This thesis aims to assess the energy demand and the carbon emission for the proposed design of Jakobsgårdarna district in Borlänge, Sweden. The complete analysis of the neighbourhood is assessed through a tool - Urban Modeling Interface, a Rhinoceros-based plugin developed by the Sustainable Design Lab at Massachusetts Institute of Technology, USA. A base case scenario is evaluated for energetic performance, lighting, heating, cooling, hot water, daylight potential, walkability, and life cycle assessment. Then, a sensitivity analysis is addressed, in particular to evaluate the impact of daylight potential, archetypes, window to wall ratio, wall materials, future climate, and a possible lockdown, on energy consumption and carbon emission. In the base case, the analysis shows that preschool has the lowest specific energy consumption of 64.1 kWh/m2, while retail shops have the highest (92.2 kWh/m2) energy consumption. The simulated energy consumption of the offices and residential buildings is 72.1 kWh/m2, and 80.4 kWh/m2 respectively. The life cycle assessment reveals the advantage of the environment from building wooden houses instead of using concrete or masonry. The total embodied carbon for the whole district is 149.3 kgCO2/m2 divided as follow: 160.9 kgCO2/m2 for the school; 164.9 kgCO2/m2 for the offices, 159.6 kgCO2/m2 for the retail shops, 55.0 kgCO2/m2 for the wood residential buildings, 164.9 kgCO2/m2 for the masonry residential buildings. The sensitivity analysis explains exhaustively the influence, which has changes in the base case scenario. In particular, the future climate will decrease heating consumption due to the increase of the mean annual temperature and, on the other hand, increase cooling demand. While a possible lockdown to the district will rise consumption in residential buildings due to a higher use of equipment and lighting, but it will lower the energy use of offices and schools. The overall research results are expected to be useful to propose suggestions and recommendations for the next steps of design about Jakobsgårdarna district in Borlänge.

The building sector is one of the largest consumers of energy and producers of greenhouse gas emissions in Ontario, representing 13% of the province’s emissions. Recently, countries have been looking to decrease their emissions in response to climate change. The electrification of space heating and domestic hot water preparation has gained traction in reducing emissions in countries with low emission electricity grids. This thesis proposes a novel energy delivery system called the Integrated Community Energy and Harvesting (ICE-Harvest) system. The ICE-Harvest system is a modified 5th Generation District Heating and Cooling (5GDHC) system. An ICE-Harvest system, much like a 5GDHC system, is a district energy system that incorporates heat pumps to couple the thermal and electrical energy demands of buildings. The ICE-Harvest system uses heat pumps to supply both heating and cooling from a one pipe thermal distribution network. The ICE-Harvest system has unidirectional mass flow in a ring arrangement with branches at each building. Bidirectional energy flow between the network and buildings is permitted, meaning that heat rejection from cooling processes can be recovered in the network to reduce the total system heating load. This concept is referred to as energy sharing. The energy needs of the network, and thus the buildings, are serviced through a centralized generation station referred to as the Energy Management Center (EMC). The EMC regulates the supply temperature of the network to the controlled setpoint. Within the EMC, the primary generation source is a Combined Heat and Power (CHP) unit. The purpose of this CHP is to offset the existing centralized natural gas generators on the Ontario electrical grid. These gas generators operate intermittently and inefficiently as a form of dispatchable generation to stabilize the provincial electrical grid. In this research, it is proposed that ICE-Harvest systems with on-site CHPs could replace these gas generators while providing the same support to the electrical grid at a much higher energy utilization ratio. For an accurate comparison, the CHP is constrained to only turn on according to the electricity system operator's gas generator dispatching schedule. An auxiliary boiler is included in the EMC to provide heat when the CHP is not permitted to operate. However, the possibility for Thermal Energy Storage (TES) to replace this boiler is also explored. An ICE-Harvest system's ideal design depends on the market conditions, building energy demands, and available waste energy sources. This research presents an ICE-Harvest system in a heating demand dominated community located in Ontario, Canada. The community consists of five buildings. The ICE-Harvest system is compared to conventional and alternative building energy systems using the energy consumption data of these buildings. The systems are compared according to their energy consumption, emissions produced, and impact on the electrical grid at both the distribution and transmission levels. The topic of using thermal energy storage in ICE-Harvest systems is also discussed, and a parameter sweep is performed on the thermal energy storage capacity. The results show that the ICE-Harvest system offers demand management opportunities to electricity system operators, substantially reduces annual emissions, and offers improved energy utilization compared to conventional systems. / Thesis / Master of Applied Science (MASc)

5th generation district heating and cooling is a novel approach to district heating and cooling networks. Instead of a centralized energy supply, the technology relies on multiple building-level energy centers, equipped with heat pumps and chillers. The energy centers are connected to a low-temperature district energy network which allows for energy exchange by rejecting the waste heat and coolth produced by the chillers and heat pumps. A growing interest in 5th generation district heating and cooling has spurred new research on the topic but there are still many unanswered questions regarding the viability of the concept, both from a technical and economical perspective. This thesis aims to increase the understanding of these types of networks by creating a simple model that can be used to evaluate the performance of a potential 5th generation district heating and cooling network, based primarily on the hourly heating and cooling demand of different building types. The model was implemented on 2 theoretical building clusters located in Bristol, UK. Cluster 1 was made up of offices, retail establishments, and hotels while cluster 2 consisted of residential buildings, hospitals, and data centers. The network was modelled after a 2-pipe closed loop system. Cluster 2 was able to limit the ratio of external heat and coolth addition to the system to 30% while cluster 1 required 53%. The low-temperature network enabled the connected heat pumps to reach a seasonal coefficient of performance of 3.4 for both clusters. The cooling equipment (free cooling heat exchanger and chiller) managed to reach a seasonal coefficient of performance of 17 in the case of cluster 1 and 18.2 for cluster 2. Distribution losses in the network amounted to about 3.2% for the warm pipe while the cold pipe gained 1.4% of coolth from the ambient. The results of the simulations indicate that the seasonality of the heating and cooling demand is one of the main factors to account for when designing a 5th generation district heating and cooling network. Highly seasonal heating and cooling demands lead to less possibilities for energy exchange on the network and will thus require more energy addition or increased energy storage capacity. The findings of this thesis seem to suggest that the advantages of 5th generation district heating and cooling networks are highly dependent on the demand profile of the connected buildings. Future research should aim to establish under what conditions these networks are economically viable. This will depend on several factors but arguably the most important ones are the amount of energy required to balance the network, cost of decentralized substations, and availability of cheap low-temperature heat and seasonal storage.

Distributionsförluster är en viktig faktor i fjärrenergisystem. Genom att optimera förluster i sådana system, kan både ekonomiska och miljömässiga aspekter uppfyllas. Tyvärr finns det ringa information om rörförluster i fjärrkylasystem. Föreliggande studie fokuserar på förluster i ett fjärrkylanät genom att både använda ett R-nätverk och FEM simuleringsmodeller. Ett R-nätverksmodell bestående av termiska konduktanser har utvecklats genom analytiska ekvationer och simuleringar med FEM har utfört för validering av modellen. Därefter har ett fjärrkylanätverk som konstrueras i Gävle, analyserats. Undersökningen omfattar 15 olika rördiametrar i tre utföranden (dubbelrör med två symmetriska och en osymmetrisk värmeisolering) och i tre förläggningsdjup (0,8; 2 och 4 meter) för en säsong om 7 månader (April t o m Oktober). Särskilt utreds ökningen av temperaturen hos framledningsmediet, där matningsrören förlagts i en å mitt i staden om en sträcka av 1 km. Den maximala förlusten under säsongen, bland alla rörkonfigurationer, motsvarar 2 % av den totala levererade energin. Slutligen konstateras att kombinationen av isolerad framledningsrör och oisolerade returrör verkar som en gångbar investering, ekonomiskt och tekniskt, men kan inte användas i hela nätet eftersom stora delar har redan byggts med oisolerade plaströr. R-nätverksmodellen, som visades vara effektiv och pålitlig i undersökningen, kan som beräkningsverktyg, framförallt för dimensionering och för att uppskatta energiförluster. / Distribution losses are a very important factor in district energy systems. By optimizing the losses in such a system, both economical and environmental aspects can be fulfilled. Unfortunately, there is few information regarding losses for district cooling systems. This study focuses on losses in district cooling networks by using both R-network and FEM simulation models. A R-network model composed of thermal conductances has been developed through analytical equations and simulations have been performed for validation. Afterwards, an in-progress construction project of a district cooling network from the city of Gävle, Sweden, is analyzed. The assessment consists of 15 pipe diameters in three configurations (two symmetric cases and one asymmetric), at three ground laying depths (0.8, 2 and 4 meters) for a duration of 7 months (April to October). A particular case in which the main distribution pipes from and to the plant are submerged in the city’s river for a distance of 1 km is investigated in order to estimate the temperature increase of the supply water. A maximum cooling loss below 2% of the total delivered energy during the season for any network configuration resulted from the calculation. Finally, the mixed pipes array seems to be a feasible investment both economically and technically but it cannot be used for the entire network spread since a part of the network has been already built with the non-insulated plastic pipes. The R-network model proved to be effective and reliable in the analysis which provides confidence that it can serve as a solid foundation for a calculation tool - primarily for design purposes and also for estimating energy loss.

Satellite District Heating and Cooling (DHC) systems offer an alternative structure to conventional, centralized DHC networks. Both use a piping network carrying steam or water to connect disparate building heating and cooling loads together, providing a platform for improving energy efficiency, reducing emissions, and incorporating alternative means of energy generation. However, satellite DHC networks incorporate thermal production units that are distributed amongst the buildings nodes, which offers greater operational flexibility and reduced capital cost savings for applications using existing building stock. This study was focused on the development of the methodology behind a comprehensive energy model that can assess the practical and financial viability of satellite DHC network scenarios. A detailed scenario application of the model demonstrated significant energy savings and investment potential. Additionally, environmental assessment methods and alternative generation technology were explored in supplementary studies of Deep Lake Water Cooling (DLWC) and building-scale Combined Heat and Power (CHP).