The concentration photovoltaics (CPV) application promises to produce lower price electricity with less semiconductor usage in comparison with the common flat plate PV module. The compound parabolic concentrator (CPC) shows great potential in both economics and efficiency in low the concentration photovoltaics (LCPV) system because it does not require a tracking system and is able to concentrate light with a large incident angle range. A detailed investigation has previously been carried out regarding the novel CPC module purposed (Su et al., 2012a). The validation of the experiment shows the Lens-Walled CPC gives a superior optical and electrical performance compared with other CPCs. Non-uniform light distribution is a common issue with all CPC designs as it has a major influence on the concentration of solar cell performance. In order to study the effects of non-uniform distributed light on solar cell behavior in-depth, two simulation approaching methods including array modelling and finite element modelling (FEM) were carried out. Both simulation approaches observed a reduction in the solar cell fill factor (FF) under non-uniform distributed light. The high resistive losses in the cell are the main cause of this phenomenon. Three simulation models with different cell grid designs were studied to further study the influence of non-uniform distributed light. The light profiles from three different CPCs were implemented with the FEM model. The result shows although solid CPC has the highest current output in a certain condition, the Lens-Walled CPC has the most uniform light distribution, which reduces the influence from non-uniform light distribution to solar cell performance.

It is undeniable that activities and events within the water, energy, and food (WEF) security nexus are inextricably linked and their relationships numerous and substantial. Complexity increases when factors governing the daily lives of humanity namely social, technology advancement, environment, economic, and policies (STEEP) adds upon the difficulty in addressing the relationships. It is thus paramount to address the problems from a holistic and systematic approach to maximise benefits as well as to minimize the negative impacts upon one another. However, there exists little to zero means of measuring their performance, whether qualitatively or quantitatively, within the context of a nexus. Moreover, minimal understanding exists regarding the relationships between the WEF securities in Malaysia, an emerging economy rich in natural resources, which envisions to be a developed nation. This research sought to establish a measurement system for the WEF security nexus in Malaysia within the context of resource security wellbeing, sectoral balance, and sustainable development using a System Dynamics (SD) approach. This entailed an extensive literature review and qualitative interview with key stakeholders from the industrial sectors. The front end of the SD process is concerned with obtaining important and relevant information from literature and interviews, which are then used to construct causal loop diagrams (CLD). The back end of the SD is concerned with converting the CLDs into a stock and flow diagram (SFD), which provides a platform for quantitative simulation of different well-designed scenarios. Key findings from this research can be highlighted; these include: renewables are necessary for the long-term energy plan of Malaysia, nuclear power is necessary to keep electricity tariff low, water tariff of supply and services are severely low, increasing self-sufficiency level (SSL) of Malaysia’s staple food is important, under-utilised crops are efficient in meeting nutrient requirements, and cash crops imposed systemic stresses upon the water sector more than the energy sector. Consequently, recommendations for policy makers are suggested accordingly to achieve a reasonable proportion of RE penetration, providing education on nuclear benefits, centralising and streamlining water governance, socio-economic improvement of water economics, increase SSL of staple food, embark upon widespread adoption of local under-utilized crops, and controlling land use of non-food crops. The outcome of this research forms a vital and novel contribution to knowledge, when it is a pioneering work to address the WEF security nexus for Malaysia; especially in considering their securities for the country as a system rather than unaffected individual entities. This work will contribute towards spearheading the awareness and, hopefully, trigger further and more in-depth work in transdisciplinary resource and technology management. As a pioneering effort, this research has nonetheless provided the foundation and the fundamental understanding to an integrative and inclusive cross-sectoral national resource backbone - The WEF security nexus measurement system of Malaysia.

In the present work, an inter principle research is carried out on complex fluid flow and heat transfer, using an innovative technology Nuclear Magnetic Resonance (NMR), from the Department of Physics. To enhance heat transfer performance of complex fluid flow, the present work mainly focuses on two different parts, one is the adoption of nanofluid; the other is flow forces analysis through bionic engineering studies on plant water migration system. Nanofluids are attracting considerable attention from both academic and industrial communities. Comparing with conventional pure fluids or solutions, nanofluids have higher thermal conductivity, due to the high surface to volume ratio of nanoparticle and liquid interface, which exhibits a great potential in enhancing heat transfer performance in various occasions. It is believed that different types and concentrations of nanofluid could strongly affect the thermal performance, and a great number of papers have been published to illustrate the phenomenon. However, none has really focused on the possible concentration change of nanofluid while flowing. Otherwise, the thermal performance of nanofluid flow could never be quantified. In the present work, a novel method to measure the dynamic concentration of nanofluid is proposed, using NMR technology. The experiments were carried out with ferrofluid under different concentration and temperature. A new parameter T2* was introduced in the study. T2* is a relaxation time of the signals that is released by hydrogen atoms after Radio Frequency (RF). And this signal intensity can be strongly affected by nanofluids. Experiments were carried out to obtain the T2* of nanofluid in the pipe. An empirical equation based on T2* and temperature was proposed to calculate the concentration of nanoparticles. Then, experiments were carried out with flowing ferrofluid in pipe. The dynamic concentration was calculated with the empirical equation. And with the series of experiment, it is confirmed that the flowing nanofluid consists of an obvious concentration gradient, and thus cause different layers of thermal performance from boundary to central line of a laminar pipe flow. Furthermore, the experiment result also gives out a chance to investigate the mechanism of nanoparticle movement in laminar flow with the concentration gradient along radius. Bionic Engineering is another research field that has been more and more interesting to researches from various fields. Since life has been evolving for over millions of years, many functions in lives has become extremely high efficiency and adaptive. These functions can be very worthy for researchers to study and utilize in industries. For heat transfer in fluid flow, it is very important to enhance the flow pattern. And thus water migration system in plants become very attractive. Plant can take water from soil up to several metres high. Learning from the water migration process in plants has been attracting interests from scientist for over a hundred years. The water migration in plant stem, especially xylem, involves various driving forces including capillary effect, osmosis effect, Marangoni effect and transpiration effect, etc. This present work mainly focuses on the water transport process within xylem. As xylem system is simplified as micro channel, a mathematic model is presented based on micro channel theory, with critical analysis and simplification. With a simplified micro channel from xylem structure and the calculation using the model of water migration in xylem, the relationship between various forces and water migration velocity is identified. The velocity of water migration within the plant stem is considered as detail as possible using all major forces involved. And a full mathematical model is proposed to calculate and predict the velocity of water migration in plants. Comparison between the calculated result and experimental one is made, to confirm the accuracy of the mathematical model. The present work proved that the mathematical model should be enough to predict the water migration in plants, and could also be critical for future water transport prediction in complex fluid flow in industry applications such as heat pipe.

The problems of excessive consumption of fossil resources, oil shortages and greenhouse gas emissions are becoming increasingly severe. Research and development work on new methods of thermal energy storage are imminently required. To effectively store seasonal renewable energy, a novel high capacity heat storage system has been designed and evaluated/validated through laboratory experiments and numerical simulations in this research. The system is driven by direct flow evacuated tube solar collector with enhanced PCM tank and intends to be applied in residential and commercial buildings. Theoretical and experimental approaches and numerical analysis have been employed in this study. Firstly, phase change materials (PCM) with specific heat density, melting point, melting and solidifying time have been investigated. This type of PCMs can maintain a considerable high internal temperature of environment chamber in a frozen ambient temperature. Numerical modelling has been conducted on a passive house (Nottingham H.O.U.S.E) to study whether proposed thermochemical materials can cover relative heating load and be power by solar panel in terms of roof size. Meanwhile, PCMs have been used to give a long duration for temperature-controlled chamber in laboratory, and thermochemical materials have been utilized in closed pumping pipe system for cooling and heating purpose. Secondly, characteristic experiments have been conducted on a modified solar collector working with an enhanced PCM tank that is integrated with a fan coil heat exchanger. The results show that light radiation of tungsten lamps (as a solar simulator) has approximately 70% efficiency to equate to solar radiation under the same Pyranometer reading value. At the same time, the solar system can supply over 50°C heating energy and the PCM tank within it can supply higher output temperature with longer duration than water tank. The efficiency of the whole solar collector heating system is over 50% as a heat absorption chamber in sunny days, while only approximately 10% under mostly cloudy weather. Lastly, proposed thermochemical materials (silica gel, calcium chloride, zeolite 13x, vermiculite and activated carbon) have been evaluated on designed thermochemical absorption chamber to supply fresh high temperature air for space heating. The results show that zeolite holds the highest reacted temperature (over 58°C) and vermiculite has really fast absorbing hydration duration, less than half hour. Silica gel possesses the biggest water absorbing capacity and vermiculite has a worse result. A comparison between experimental and numerical modelling results has been revealed. Considering the complexity of processes in cooling and heating system, the agreement of simulation and experimentation is satisfactory, thus the lumped numerical model is acceptable and significant for investigation of this scaled seasonal high capacity heat storage system. A full size seasonal heat storage system with a nominal heating capacity of 3kW has been proposed and illustrated in economic and environmental issues section. The results from net present value (NPV) and internal rate of return (IRR) sensitivity analysis both shows it is greatly attractive to develop this novel system for application in both household and commercial buildings in consideration of its about 9 years payback period, 20 years life span and zero gas (C02) emissions. An intelligent transpired solar collector system is also introduced and illustrated as future work.

Shading louvres on buildings must serve to allow maximum window insolation in winter, while have the prime function of intercepting unwanted direct solar radiation in summer; which could cause excessive solar heat gain, especially in glazed offices and commercial spaces. Studies of the effect of solar protection on heating and cooling loads show that shading strategies are climate dependent. And it is accepted today that solar protection does reduce energy use for cooling, and tends to increase heating loads. The balance between the benefits in cooling and the losses in heating is only achievable by good designs. The main focus of this research work has been in harnessing the thermal energy available within the incident solar radiation intercepted by the shading louvres; hence benefiting, from shading in terms of energy savings, as well as from the collected energy. In achieving this aim, both theoretical and experimental techniques have been utilized, as design analysis tools, in order to select a design that satisfies both the efficiency and cost criteria. A suitable collector design has, then, been identified, its thermal performance characterised, and its prototype manufactured and built. The prototype of the chosen design has been field-tested in Nottingham-England and Porto-Portugal. Finally, the characteristics of the design have been incorporated into a computer simulation scenario, in which a real office building in Winterthur-Switzerland has been analysed for its total (cooling and heating) annual energy consumption. Findings of this research work indicate that these louvres, despite certain geometrical limitations, could act as solar collectors with good energy collection characteristics. And they could contribute with substantial reductions in the overall annual energy consumption resulting from the combined effect of shading and collecting energy. This was found particularly to be the case when the collected energy is made to part-fuel, an adsorption chiller for the purpose of air-conditioning the same building.

Renewable energies are a critical element for reducing greenhouse gases emissions and achieving a sustainable development. Until recently, building integration of renewable sources was focused on solar technologies. Nevertheless,building integrated wind turbines can and must be part of the solution to the global energy challenge. This research investigated the potential of integrating small vertical wind turbines between medium-rise buildings. Wind velocities were measured around 7 fifteenstorey towers. The measurements were carried out for nine different configurations,using a boundary layer wind tunnel and computational fluid dynamics (CFD) simulations. Computed and measured results showed reasonable agreement. The differences were more apparent at ground level. It was established that building orientation and the separation between buildings defines to a great extent the wind environment around buildings. It was found that a distance between buildings of 15 metres and an orientation of θ=260˚ produced the higher augmentation factors. This configuration produced up to 17,812kWh in a typical Nottingham UK year, using six vertical wind turbines of 2.5kW each. Results suggested that the use of CFD as a visualisation tool is extremely useful at design stages in projects involving the integration of wind turbines. Nevertheless, the results of CFD simulations are highly dependent on the type of roughness modification applied to the wall functions, the choice of the turbulence model and the modelling of the inlet wind velocity profile. Because servicing buildings accounts for around half of the UK’s total energy consumption, the need to reduce the consumption of fossil fuels is central to good building design. That is why the architectural practice must respond professionally by delivering buildings that successfully integrate wind energy technologies, which can only be achieved if the designer actively engages with the environmental design principles and improves his understanding of building physics.

Conventionally the power network operators were obliged to buy all the wind energy generated by wind farms. However, as the penetration of wind energy (or generally any other sort of renewable source) in a power system is increased, the ability of other generators to balance the demand becomes limited. This will necessitate the control of wind turbines in order to generate a given demand power rather than extracting the maximum wind power. This control approach is termed “Power Demand Control” in this thesis. In contrast to Power Demand Control, “Power Smoothing Control” utilizes energy storage systems in order to absorb high frequency wind fluctuations, hence, delivering a smoother version of wind power into the grid/load. The drawback of the Power Smoothing approach is that the average power into the grid/load is still determined by the available wind power rather than the system operator. The Power Demand Control approach, which has received little attention in literatures, is the main focus of this thesis. This research proposes control schemes with and without external energy storage for the Power Demand Control strategy. This thesis studies different possible methods of applying Power Demand Control, in particular the droop control method. It is shown that a droop-controlled wind farm does not need a central “Supervisory wind Farm Control” unit to determine the power demanded from each DFIG. Moreover, a droop-controlled wind farm has the advantage of controlling the local grid voltage and frequency. This means that no external voltage and frequency source is required which makes a droop-controlled wind farm a more suitable option for integration of wind energy at distribution level. The classical droop control is modified in order to make the DFIGs share the demand power not only according to their ratings but also to their associated available wind power. The applications of the control paradigm are discussed, including: integration into microgrids, AC grids and HVDC connection feeders. This work mainly concentrates on microgrid applications. An Energy Management System is proposed in order to keep the energy level of the energy storage (or the DFIG’s shaft speed) within its limits using an Auxiliary Generator and a Dispatchable Load. Different possible system configurations are introduced and their advantages and drawbacks are discussed. It is illustrated through simulation that the proposed control scheme can inherently ride-through a grid fault with no need for communication. Furthermore, it is shown that the control scheme can operate if the wind speed drops to zero. The simulations are carried out using the PSCAD/EMTDC software.

This thesis considers historical applications of naturally renewing energy resources in Britain from the beginnings of public electricity supply in the late nineteenth century to the period immediately prior to the first State interest in such technology in the early 1980s when it became conceptualised as 'renewable'. After a comprehensive review of twentieth century engagements with renewable energy and the academic literatures pertaining to 'water, engineering and landscape' the thesis focuses on two distinct case studies. The first charts the technological, cultural and political evolution of hydro-electricity for public supply which developed over the course of the nineteenth century and was instituted from the 1870s. Detailed consideration of the Worcester hydroelectric station reveals that the development of hydro-electricity in the late nineteenth century symbolised a wider social and cultural demand for 'civic improvement’, and highlights the nature of water as a contested resource within late-Victorian civic arenas. The second traces the history of the Centre for Alternative Technology (CAT), a practical demonstration of alternative energy technologies established in rural mid-Wales during the early 1970s. In a discussion centred on 'alternativeness', the exploration of alternative energy technologies in the early 1970s was the preserve of an emerging counter-culture which sought to implement new visions of Environment and Society. Having revealed these hitherto dormant histories, the thesis concludes with a comparative discussion of the two case studies reflecting on these respective renewable energy projects and their uses as instruments of ‘modernisation' and attempts to extract the significance of these histories in the context of current discourses of renewable energy.

The UK has committed to sourcing 15% of its energy from renewable sources by 2020 and wind turbines have the potential to contribute towards this target. Due to the Feed-In-Tariffs introduced by the UK Government in 2010, the potential uptake of micro-generation methods such as small wind is likely to increase. However, many barriers exist which prevent widespread implementation, such as noise concerns. There is little work available in the open literature quantifying the problem because much of the existing research focuses on large scale turbines. The need for an increase in interdisciplinary research in this area has also been called for. This research fills the gap in the literature by seeking to better understand the noise levels generated by small wind systems, the characteristics of the noise and people’s reactions to this noise. The research is interdisciplinary, incorporating engineering, to measure, characterise and model the noise from small wind systems and psychology, to identify the type of people who are most likely to perceive the noise. Environmental noise measurements have been taken at small wind system installations to quantify and characterise the noise levels. This work included an assessment of the attenuation of the noise. Studies have been carried out on individuals living close to small wind system installations, as well as individuals being played recordings of wind turbine noise to investigate the level and type of noise they perceive and to link this to an individual’s attitude towards wind turbines, personality traits and symptom reporting. CFD has been used to model the flow fields around 2D blade sections to identify the likely noise mechanisms associated with small wind systems by observing the turbulent regions near the aerofoil wall. Finally, a comparison of the three methods has been carried out to identify that the overall level of small wind system noise is low but it is the nature of the sounds that increase the likely perception of the noise.

In this study, it is aimed to develop an innovative thermochemical energy storage system through material, reactor and process based investigations for building space heating applications. The developed system could be integrated with solar thermal collectors, photovoltaic panels or heat pumps to store any excess energy in the form of heat for later use. Thereby, it is proposed to address the problem of high operational costs and CO2 emissions released by currently used fossil fuel based heating systems in buildings. The aim of the study has been achieved by investigating and evaluating five of the following aspects: • Investigation of the feasibility of building integrated solar driven THS system under cold and mild climates, • Synthesis, characterization and physical experimentation of novel composite sorption energy storage materials • Development and investigation of a modular laboratory scale sorption reactor that use embedded air diffusers inside the sorbent for improving the energy storage density • Development and investigation of a full- scale modular solar driven THS system • Development and investigation of a heat pump driven sorption storage heater using multi-layer fixed bed sorption reactor These works have been assessed by means of computer simulation, laboratory and field experimental work and have been demonstrated adequately. The key findings from the study confirm the potential of the examined technology. Initially, a comprehensive review on thermal energy storage, with the aim of investigating the latest advancements on THS systems was performed. A comparative analysis on applicability of different heat storage methods for short term and seasonal heat storage under climate conditions in the UK, was also carried out. Results showed that short term heat storage is not a feasible option in the UK due to the very limited solar radiation. For the case of seasonal heat storage, it was found that, each 1 m3 of THS can provide averagely 14% of monthly (October to March) heating demand of a 106 m2 building, whereas LHS and SHS can provide 6% and 2% respectively. Later on, a range of candidate composite sorption materials were synthesized and characterized. Based on the applied characterization techniques, it was found that Vermicuilite-CaCl2 (SIM-3a) has excellent Ed coupled with good EMC and temc with its TGA analysis also suggesting significant mass loss in the working range 30 < T < 140 °C. Physical experimentation of the developed materials in a small scale custom test rig was also performed and in accordance with the characterization results, SIM-3a displayed the best hygrothermal and cyclic performance. These findings suggested that SIM-3a has very good potential for use in an open THS system. Upon completion of the material based studies, a 3kWh laboratory scale novel reactor using perforated pipes embedded inside the heat storage material was developed. The overall energy density of the reactor using SIM-3a was found 290 kWh/m3. Based on the obtained encouraging results, same concept was up scaled to a modular 25 kWh sorption pipe heat storage and similar energy density was achieved. Following the experimental work, theoretical analysis of the THS potential in Mediterranean climate conditions is conducted with a case study of the Island of Cyprus. The analysis results showed that the required heat storage volume to fully compensate heating demand of a domestic building in winter (December to February) is 5.25 m3 whilst the time required for charging the THS material with 8 m2 solar air collectors is slightly more than a month. The economic and environmental analyses results showed that payback period of the solar driven THS is 6 years whilst total CO2 emissions savings over 25 years lifetime is 47.9 tonnes. In order to validate the applicability of THS in Cyprus, a small prototype of integrated sorption pipe-solar concentrator was also developed and tested for room heating. It was found that adsorbent could be regenerated with solar energy during winter day time to be utilized at night for space heating. Study results also showed that sorption pipe with a heat storage volume of 0.017 m3 could meet up to 87% of the daily heat demand of a 12.4 m2 building. In order to validate the performance of the laboratory tested THS material and concept, a real scale (1000 kWh) modular solar driven THS system was developed based on the interpretation of the obtained theoretical, numerical and experimental data in earlier stages of the study. The preliminary testing on the prototype showed that each of four reactors could discharge a total of 248 kWh of thermal energy with an average thermal power of 4.8 kW. Additionally it is found that, in direct solar heating mode, transpired solar collectors used in the system could also generate daily total of 17 kWh thermal energy for the average solar intensity of 0.3 kW/m2. In the final stage of the study, a heat pump driven sorption storage heater was developed and investigated. The developed system performance was assessed with 5 different adsorption materials and under different operating conditions. The study results showed that Sim-3a and Vermiculite–(LiCl-CaCl2) (Sim-3cl) has the best hygrothermal performances and hygro-cyclic efficiencies. According to study results, COPs varies in the range of 1→2 depending on sorption materials properties and system operating conditions.