The core response to the Kyoto protocol policy is reflected in the Energy Performance of Building Directives due to the recognition of built environment as being one of the major contributors to the global Greenhouse Gases emission. In Europe, the Energy Performance Certificate (EPC) has become a mandatory requirement for all buildings including dwelling stocks. The perceived benefits of sustainable buildings have resulted in increased interest in measuring the implicit price and rent impacts of green/energy labels. However, the relationship between energy performance and residential property remains under-researched, geographically diverse, and inhibited by a paucity of data. This research aims to establish whether there is a green premium associated with residential buildings within the Belfast Metropolitan Area. Hedonic pricing models are used to establish the complex relationship between property characteristics, energy performance ratings, and green features. The study has assembled 6,671 and 3,928 datasets consisting of property characteristics for sales and rental markets respectively from quarter one 2013 to quarter two 2014. Modelling techniques are specified in linear, semi-log, and price/rent per square metre to measure the implicit prices and rents of energy performance ratings in monetary, percentage, and monetary/percentage per square metre respectively. The resu Its illustrate evidence of a green premium effect. Using EPC scores as a measure of energy efficiency, an additional price of £435 or 0.3% or £4.32 psm per EPC score was evidenced for the owner- occupied market. Meanwhile, a premium of £1.39 or 0.2% or £0.02 psm per EPC score was observed for the private-rented market. Comparative models with banded EPC scores illustrated increased premium from energy inefficient to efficient houses. The largest magnitude of increase was observed for B rated houses (compared to D rated houses) with 26% and 16% of premiums observed in the owneroccupied and private-rented market respectively. Nonetheless, the premium is complicated by the heterogeneity of the existing property stock. Diminishing premium effect observed for new houses reflect no-bid factor for sustainability as they were assumed integrated into the houses by the market. In addition, the analysis suggested the potential for retrofitting of dwellings with existing low energy performance. In particular, the results from this thesis suggest that thermal features should be prioritised in retrofit measures. Specifically, current policies should target to improve energy efficiency of stocks through double-glazed windows, floor insulation, roof insulation, and wall insulation.

As members of the European Union (EU), the United Kingdom (UK) and Ireland are legally bound to integrate large penetrations of renewable energy into the power system in pursuit of EU 2020 targets. Wind power has emerged as the main renewable energy technology of choice to meet these targets. As the penetration of wind power continues to increase beyond 2020, a wider lens on the integration problem is required, It has been previously shown that gas generation due to its flexibility provision and traditionally high place in the merit order is the sacrificial generator. The ensuing dispatch schedule reduces energy output and incorporates a high degree of variability. This increasingly variable output profile is ultimately transferred onto gas infrastructure and is a relatively overlooked area of research This work is the first to utilise a fully realistic gas energy flow, security and reserve constrained unit commitment and economic dispatch model to investigate the interactions between power and gas vectors In the Interconnected energy systems of the UK and Ireland. Utilisation of this novel modelling methodology produced four key deliverables, Firstly, the real world impact of high wind power penetrations on gas generators in the SEM during 2011 were analysed in detail The second deliverable, novel utilisation of grid scale electrical storage coupled to a constrained on gas generating unit in the SEM during 2020, was shown to have significant impacts on peak' time system operation. Thirdly, the multi vector analysis conducted enabled the value of gas infrastructure to power system operation in the SEM to be determined, Finally, the research highlights the ability of extreme weather driven gas demand to impact unit commitment decisions in both the SEM and BETTA. Additionally, the presence of gas storage in Ireland is shown to significantly improve power and gas security of supply.

The aim of the thesis is to study the optimal operation of compressor stations in systems with large energy consumption such as process systems and natural gas networks. Compressor stations include several compressors in parallel which usually account for the major part of the total energy consumed in the system. Therefore, the efficient operation and maintenance of the compressors could save energy, and reduce operational costs. The development of optimisation frameworks and optimisation models can determine the decisions which lead to the minimisation of costs operating compressor stations. The modelling of the behaviour of the compressors is also an important topic of the current PhD study. Different types of models should be used according to the level of optimisation level (online and real time, and offline), considering the available resources such as compressor maps or process data. The thesis developed a comprehensive real time optimisation framework which can reduce the power consumption of compressor stations compared to the case of operation with the existing industrial practices. The thesis also developed a mixed integer linear programming multi-period optimisation model to minimise total costs of the operation, for example electricity costs, and start up and shut down costs. Another contribution of the thesis is the integration of operation and maintenance of the compressors considering different types of maintenance activities such as major overhauls and the washing of compressors. For example, the proposed integrated framework can be used to generate the schedules of the online and offline washing of the compressors compared to existing approaches described by fixed periodical washing or washing when the degradation of the condition of the compressors has reached unacceptable limits. The optimisation frameworks was applied to two industrial case studies, namely one air separation plant involving a network of air compressors in BASF, Ludwigshafen, Germany and one export natural gas compressor station operated by Statoil in Norway. The final chapters of the thesis discuss the contributions and assumptions of each method, and present potential new research areas deriving from the PhD study.

This research answers the question: what is the potential of community renewable energy projects to reduce carbon emissions in the United Kingdom (UK)? This research provides evidence of the benefits of community energy projects in the UK that have been identified as lacking in a recent report produced for the Department of Energy and Climate Change. The work is based on analysis of primary data collected from 13 community energy projects that were active in 2011 in England and Wales. The 13 projects were based around energy generation and cover three types of technology: photovoltaic (PV), wind turbine and hydro power. A qualitative assessment is carried out of interviews conducted with representatives of the community energy projects to examine why certain actions are taken during the development and delivery of the projects. Life cycle assessment (LCA) methodology is applied to these case studies to calculate their carbon impact in three areas: directly through installation of the project; indirectly through use of the income stream created by the project; and indirectly due to behaviour change in the community caused by increased knowledge and/or acceptance of energy generation and climate change issues. The LCA results are then used to model the potential impact of the community energy projects that have already been installed in the UK. The results of the work suggest that community energy projects do generally reduce carbon emissions in the UK. However use of the income stream typically reduces the potential for the community energy project to reduce carbon emissions. Behaviour change in households to install additional energy generation can increase the potential for the community energy project to reduce carbon emissions. The impact, both positive and negative that government policy has had on the sector is significant despite the perceived independent nature of the sector.

Combined Heat and Power and District Heating technology systems (CHP-DH) is a network-based infrastructure known to offer a more efficient and more sustainable option for meeting society’s energy needs with reduced emission production in the face of increasing population and energy demand compared to other forms of conventional thermal plants. Specifically, this brings to the fore the potential importance of these systems, their rate of penetration and what factors are militating against their diffusion. The United Kingdom (UK) currently exhibits a low penetration of CHP and particularly CHP-DH systems in terms of contribution to both electricity and heat generation profile with the adoption of these systems failing to meet their potential over decades. This is despite Government commitments to meeting environmental targets for emission reduction and 2020 energy targets from renewable energy by introducing several governance mechanisms. This failure suggests that these mechanisms have not fully captured the potential of CHP-DH systems to achieve these targets. Secondly, it is also not clear that the UK has adequately considered heat energy as a critical aspect of the energy vector to meet its energy target, based upon the limited governance infrastructures to facilitate the efficient generation and distribution of heat. This thesis focuses on investigating the inducing and blocking mechanisms that influence the diffusion of CHP-DH systems in the UK using both a technological innovation system approach and governance theoretical concepts with a view to proposing alternative governance pathways to influence the CHP-DH penetration. Qualitative and quantitative methodologies are adopted here. A wide selection of stakeholders is consulted to identify barriers and assess potential solutions with a view to examining possible strategies for both communities and society at large to harness the potential of CHP-DH in meeting energy, environmental and social targets. The results suggest several governance options that seek to influence the diffusion of CHP-DH systems in the UK. Summarily, it highlights the roles that hierarchies of governance (State and Local Authorities) can play in influencing the diffusion of the technology, with the state to evolve a joined-up policy portfolio to stimulate investment and growth of CHP-DH systems and the LAs as prime movers of the CHP-DH TIS taking up “doers and enablers” roles in the penetration of the technology. Thereby contributing to the energy policy debate by persuading the hierarchies of governance to see CHP-DH systems through the lenses of a network-based infrastructure and consider alternative governance mechanisms that may ultimately enhance the selection environment of CHP-DH systems in the UK.

Like many other developing nations Bangladesh has a very poor electrification rate especially in the rural areas. Millions of people here are excluded from the benefit of globalization because of no access to necessary electricity supply. This research work proposes decentralized renewable hybrid mini-grids as a potential approach for off-grid rural and remote area electrification in Bangladesh. Based on the available renewable resources an area specific resource map has been developed. The characteristics of the bottom of the economic pyramid market including customers’ attitude to switch from liquid fuel to mini-grid based electricity supply, expected load demand and their willingness to pay have been explored through a field study. Different combinations of hybrid systems have been designed and optimized using the HOMER micro-grid design software to cover the whole country. Results suggest that serving the required load over wider hours rather than having the same load concentrated in a short span of time can achieve better hybrid system performance. Initial capital subsidy of 40 percent along with 5 percent interest on loan has been applied in accordance with the renewable energy policy of Bangladesh government. Proposed optimized rice husk-diesel hybrid system in Rangpur, micro hydro-PV system in Rangamati, wind-PV system in Chakaria and PV-diesel system in coastal areas can produce electricity for USD 0.172/kWh, 0.291/kWh, 0.217/kWh and 0.316/kWh respectively while serving loads for 12 to 18 hours a day. Field data analysed by applying the dichotomous choice contingent valuation method revealed that customers are willing to pay maximum of USD 0.43/kWh. The value difference between the cost of electricity generation and the customers’ willingness to pay creates the opportunity to attract the private investors. Suitable business delivery models have been identified and explained for successful mini-grid business by private investment. Optimum hybrid systems have been standardized for replication and a sustainable business model has been suggested for scaling up this electrification approach.

As a promising and green method, wastewater purification techniques based on photocatalyst have received much attention in recent years. However, problems such as low quantum efficiency, limited light responding range and recovery problems limit the further applications of photocatalyst-based materials. In this study, a Ag3PO4 photocatalyst with tube-like structure has been synthesized by self-assembly at room temperature. The properties of the catalyst are investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM) and N2 adsorption-desorption. The photocatalytic activities of the tube-like Ag3PO4 are mainly studied by degradations of methyl orange (MO) and rhodamine B (RhB) organic dyes. The effects of pH values and stabilities on photocatalytic performance are studied as well. The results reveal that the tube-like Ag3PO4 exhibits greatly high activities for the degradation of RhB solution under acidic condition. The excellent activities of the photocatalyst are due to the small dimension, unique nanostructure and specific surface property. Importantly, Ag3PO4 photocatalysts are found with unexpected photocatalytic activity (completion degradation of RhB-MO mixed dyes in 28 h) under natural indoor weak light, of which the light intensity (72 cd) is one in a thousand that of a 300 W Xe lamp (68.2*103 cd). The degradation of simulated wastewater containing organic dyes and inorganic ions by Ag3PO4 under indoor weak light also reveals the potential of Ag3PO4 in practical applications of wastewater cleaning and environmental remediation by solar energy-driven photocatalysis.

Availability of good drinking water is a key factor for health and quality of life. In urban locations of Ghana, water from large rivers is abstracted and treated before it is supplied to the urban people by the use of the grid. However access to potable water is difficult in rural communities of the country because these locations are remote from the grid (or they experience unreliable power supply) and water infrastructure. They are however endowed with abundant sunshine (5-8 hours per day with irradiation ranging 3.1-6.5 kW/m2-day), small rivers and streams. In spite of these natural resources, the potable water (from local treatment plants and groundwater sources) coverage in most of these locations is as low as 21%. During the dry season, the water levels reduce and some dry up completely making water and sanitation major development concerns for communities in these locations. This research therefore sought to explore the viability of solar PV water pumping in rural locations of Ghana, using the Agotime-Ziope district as case study. The case-based action research addressed the factors that influence the take up of solar energy for water pumping in rural locations of the country. Both quantitative and qualitative studies were conducted. Quantitative results derived from a questionnaire and qualitative obtained from the interviews conducted with the district officials, stakeholders in the solar industry and villagers in seven specific communities, are presented. The quantitative and qualitative approaches were mixed in the study. Furthermore, a solar PV pumping system for Kporta community was designed, installed and the system’s performance was evaluated in relation to how the people in the community collected water from it. The new PV system supplies adequate water to the people as it was designed, thus demonstrating the viability of solar PV for water supply. This notwithstanding, the system was underutilized by the community; since out of the 1,825,000 litres of water it was designed to supply in one year, only 5.2 % of water was collected from the system in one year. Two reasons are suggested for the low patronage: firstly, the borehole water at Kporta had a high content of magnesium, sulphate and chloride above WHO’s standard values making the water hard and taste salty. Secondly, water is available (free of charge) from the community pond (dam) which is perceived to be better (water is soft and does not taste salty even though unhygienic). On the other hand, in Lume Avete where a PV system supplies high quality safe drinking water (water is soft and does not taste salty) from underground, the community makes maximum use of the system. High upfront PV system cost and lack of awareness of the technology also influence its adoption and wider diffusion. Two frameworks were developed within the thesis; one for the PV system market structure and the other for its financing to address the cost and awareness factors. Within the financing framework are five models namely; 100 % upfront cash payment, fee-for-service, build operate and transfer, donation and PV utilization loan. It is recommended that future research should develop methods to remove salt and dissolved minerals from groundwater in the district and develop a better understanding of how best to supply safe water in rural areas of the country.

This thesis presents simulation results and experimental data for a collector type with an all-round supported absorber and a fully adhesive edge bond that is produced on a highly automated production line. A literature review discussing measures to reduce the convective heat loss in flat plate collectors as well as on the status quo of the collector production was conducted. It was determined that an adaption of an existing automated production technique from the insulated glazing industry opens new paths towards a collector design allowing a mass production and an improved thermal collector efficiency. Within the thesis, the thermal and mechanical behaviour as well as the applied production method for this collector type are discussed. By implementing and validating a finite element model of the collector, the absorber deflection was analysed, different calculation approaches compared and conclusions drawn on the pressure change in the cavity of gas-filled collectors. Unlike stated in the literature, it was found that the thermal elongation of an all-round supported absorber has a considerable effect on the overall collector performance. Based on these conclusions, an optimised sheet-pipe absorber structure is introduced allowing a predictable absorber deflection and, thus, reduced chance of contact between absorber and glazing in collectors. The findings of the thermal simulation and, in particular, on the convective heat transfer confirmed the reliability of a recently extended convection calculation approach for solar collectors. Even though the gas-filled collector is capable of a superior thermal performance, simulation and testing results could not confirm the calculated efficiency increase given in recent literature. In comprehensive testing, the strengths and weaknesses of different batches of prototypes are discussed. Based on an economic analysis considering the collector production costs and the solar yield, the new approach was compared to a conventional solar collector.

National Grid’s future energy scenarios depict increased wind capacity and use of domestic heat pumps under four different pathways at a national annual resolution. The factors which will drive the resultant electricity generation and demand vary over significantly smaller resolutions in both space and time. This study presents a method which disaggregates these scenarios temporally to an hourly resolution and spatially to a 0.5o x 0.5o grid, which covers the GB land mass and offshore waters. The gridded framework facilitates the development of a wind generation simulation model, SpWind, and a hybrid energy demand simulation model, SpDEAM, that are both driven by climate reanalysis data, which provides spatiotemporally homogeneous and accurate hindcasted weather data over the 25 year period of the scenarios. A range of methods are identified and applied to disaggregate non spatial data and redistribute non gridded spatial data to the grid, which depict scenarios, and drivers of wind generation and energy demand. Evaluations of the reanalysis wind speed data, SpWind and SpDEAM demonstrate a reasonable degree of accuracy; the data, in combination with a gridded approach, is appropriate for simulating turbine output and electricity demand, though some uncertainty and error remains. Wind capacity and heat pumps are assigned to the grid, ensuring that each are exposed to realistic weather conditions. The implications of the scenarios on residual demand variability, geographical diversity and extreme events are explored in detail revealing the relative impact of different factors driving demand and supply.