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Wang, Yaoping. "Climate Change and Its Effects on the Energy-Water Nexus." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1534307556870925.
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Kilimo, Abrahaman Salum Guji. "Innovative techniques of employing small hydropower plants in distributed electricity generation." Thesis, Cape Peninsula University of Technology, 2011. http://hdl.handle.net/20.500.11838/2184.
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Thesis (DTech (Electrical Engineering))--Cape Peninsula University of Technology, 2011.Electricity is the most convenient form of energy. It can be easily transported to long distances and converted into other forms of energy that is required for any technological process. The impact of availability of electricity on a society touches health, education, economic prosperity, living standard of people etc. The generation of electricity using hydropower started with waterwheels as prime mover which led to the development of modern day hydraulic turbines which caused rapid construction of large hydro schemes for bulk electricity generation in the zo" century. Later electricity generation was dominated by fossil powered power plants. In this race small hydro schemes were found to be comparatively uneconomical and hence partially abandoned. Escalation of prices of fossil fuels and environmental concerns has made people to seek alternative energy sources and preferably renewable sources. Hydro power both large and small is the most effective renewable energy source and small hydro causes negligible stress to the environment. Adding to current achievements in the fields of civil engineering works, machines and power electronics, small hydro has become an attractive alternative energy source. For developing countries like Tanzania, small hydro can enhance efforts of electrification of rural communities.
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Contreras, Sergio. "Regional electricity demand in the United States." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2008. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Bergman, Andrew. "Determinants of Fuel Choice in New Electric Power Plants." Scholarship @ Claremont, 2013. http://scholarship.claremont.edu/cmc_theses/774.
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Despite increasing fuel cost volatility, regulatory uncertainty, and imminent shifts to industry dynamics, utility managers are forced to make tough decisions in regards to installing long-life generation assets. This study seeks to identify and quantify determinants of fuel choice in new electric power plants given vast uncertainties in the electricity generation sector.
Using a probit functional form to estimate marginal effects on the likelihood of choosing wind versus natural gas powered generation, I find positive effects of natural gas prices in the period three years prior to initial operation of the new facility, positive effects of static-level standard score of mix, and positive effects of wind-power density. Additional feedstock choice sets and parameters are considered.
All models suggest that (a) feedstock costs are significant predictors of fuel choice, (b) state-level regulatory learning enhances likelihood of choosing relatively young technologies, (c) Renewable Portfolio Standards result in artificial substitution between wind and solar technologies, and (d) population density, more so than political influence, predicts choices to install wind-powered capacity. Public policy and managerial implications are discussed.
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Ershad, Ahmad Murtaza. "Potential of Solar Photovoltaic and Wind Power Plants in Meeting Electricity Demand in Afghanistan." University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1398944251.
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May, John R. (John Robert) 1978. "Sustainability of electricity generation using Australian fossil fuels." Monash University, Dept. of Chemical Engineering, 2003. http://arrow.monash.edu.au/hdl/1959.1/9537.
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Sharabaroff, Alexander M. "An assessment of the impact of the deregulation of the electric power sector in the U. S. on the efficiency of electricity generation and the level of emissions attributed to electricity generation." Ohio : Ohio University, 2008. http://www.ohiolink.edu/etd/view.cgi?ohiou1210903115.
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Assémat, Céline. "Management of thermal power plants through use values." Thesis, KTH, Elektriska energisystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-175811.
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Electricity is an essential good, which can hardly be replaced. It can be produced thanks to a wide rangeof sources, from coal to nuclear, not to mention renewables such as wind and solar. In order to meetdemand at the lowest cost, an optimisation is made on electricity markets between the differentproduction plants. This optimisation mainly relies on the electricity production cost of each technology.In order to include long-term constraints in the short-term optimisation, a so-called use value (oropportunity cost) can be computed and added to the production cost. One long-term constraint thatEDF, the main French electricity producer, is facing is that its gas plants cannot exceed a given numberof operation hours and starts between two maintenances. A specific software, DiMOI, computes usevalues for this double constraint but its parameters needs to be tested in order to improve thecomputation, as it is not thought to work properly.DiMOI relies on dynamic programming and more particularly on an algorithm called Bellman algorithm.The software has been tested with EDF R&D department in order to propose some modellingimprovements. Electricity and gas market prices, together with real plant parameters such as startingcosts, operating costs and yields, were used as inputs for this work, and the results were checkedagainst reality.This study gave some results but they appeared to be invalid. Indeed, an optimisation problem wasdiscovered in DiMOI computing core: on a deterministic context, a study with little degrees of freedomwas giving better profits than a study with more degrees of freedom. This problem origin was notfound precisely with a first investigation, and the R&D team expected the fixing time to be very long.The adaptation of a simpler tool (MaStock) was proposed and made in order to replace DiMOI. Thisproject has thus led to DiMOI giving up and its replacement by MaStock. Time was missing to testcorrectly this tool, and the first study which was made was not completely positive. Further studiesshould be carried out, for instance deterministic ones (using real past data) whose results could becompared to reality.Some complementary studies were made from a fictitious system, in order to study the impact of someparameters when computing use values and operations schedules. The conclusions of these studiesare the little impacts that changes in gas prices and start-up costs parameters have on the global resultsand the importance of an accurate choice in the time periods durations used for the computations.Unfortunately these conclusions might be too specific as they were made on short study periods.Further case studies should be done in order to reach more general conclusions.
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Chan, Pang. "Optimization of a long-term electricity contract in a large-scale chemical production site /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CENG%202004%20CHAN.
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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.Includes bibliographical references (leaves 92-95). Also available in electronic version. Access restricted to campus users.
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Hameedi, Ayoub. "Addressing the Electricity Shortfall in Pakistan through Renewable resources." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-188697.
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This report focuses on addressing the electricity shortfall in Pakistan with the help of renewable resources. At present, the country is facing a shortfall of almost 7,000 megawatts (MW) which is affecting every walk of life and causing almost 1.5 to 2% GDP loss on annual basis. Previous research done on this subject reveals that electricity demand has always remained high then the total generation capacity of Pakistan. Similarly, it has been pointed out that the country is not taking maximum benefit from its available hydro, solar and wind resources. This leads us to the basic purpose of this research which is to have an exploratory understanding of the strategies adopted by India, China, Brazil and Spain for electricity generation in a green fashion and how can these strategies be implemented in Pakistan. Case study has been adopted as methodology for this purpose. This research work also discusses the factors contributing in the lack of promotion of renewable energy resources in Pakistan and provide detailed analyses of positive changes these projects can bring in lives of masses in Pakistan. The sustainable management of surface water resource in the country has been discussed in particular as the country faced worst floods in its history during years 2010 & 2011. It will result in enhancing the surface water storage ability of Pakistan which will significantly reduce our dependence on underground water reserves and will directly increase our electricity generation capacity through hydro dams. Similarly, sustainable forest management has been discussed at length as it will not only ensure environmental sustainability but will also result in increase availability of biomass. Not to mention the fact that wood biomass is much cheaper then conventional source of electricity generation provided it is obtained through sustainable forest management. Finally, if all the green strategies discussed in this research work will be implemented, it will increase the overall electricity generation capacity of Pakistan up to 9% respectively.
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Pawananunt, Somyos. "A study on safety and risk control management perceptions for Bang Pakong Power Plant of the Electricity Generating Authority of Thailand." Online version, 1998. http://www.uwstout.edu/lib/thesis/1998/1998pawananunts.pdf.
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Chakauya, Ereck. "Effect of manipulating pantothenate biosynthesis in higher plants." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614866.
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Swart, Christopher. "Optimising the operation of underground mine refrigeration plants and ventilation fans for minimum electricity cost / Christopher Swart." Thesis, North-West University, 2003. http://hdl.handle.net/10394/339.
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This study describes the development and use of a mathematical model that will enable mine operators to
minimise the costs of electricity consumed by the ventilation and refrigeration systems used for
environmental control in deep mines.
This model was calibrated and tested by using actual data from a gold mine near Welkom in South
Africa. In a first simulation, the mine's current practice of controlling conditions to a wet bulb
temperature (Twb) of 25S°C, was optimised. The model demonstrated that this environmental condition
could be sustained at lower electricity consumption. In so doing, the mine realised a saving of 30 000
kWh per day. The energy saving and load management led to a cost saving of R 1.5 million per year.
However, a better indicator of environmental conditions is the Air Cooling Power index, (ACP).
Research has shown that for hard physical work in hot conditions workers need an ACP of 300 w/m2. It
was found that the case study mine actually supplied their workplace with a cooling capacity of 422
w/m2. The new model optimised the refrigeration and ventilation systems in such a manner that the
workers were supplied with exactly 300 w/m2, no more and no less. It was found that by doing this, an
electricity saving of 57 600 kWh per day could be realised when compared with the current mine
practices. The energy saving and load management led to a potential cost saving of R 2.55 million per
year. (Certain capital costs, such as for variable speed drives may have to be incurred to realise these
savings.)
The new model could be further extended to take advantage of the new Real Time Price offerings from
Eskom It will be able to identify an operating point for the refrigeration and ventilation systems to
supply 300 w/m2 for the workers, in real time, at the lowest electricity cost.Thesis (Ph.D. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2004.
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Lykidi, Maria. "The optimal management of flexible nuclear plants in competitive electricity systems : the case of competition with reservoir." Thesis, Paris 1, 2014. http://www.theses.fr/2014PA010082.
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L’énergie nucléaire, qui est une technologie de génération largement utilisée dans des systèmes électriques, est caractérisée par des coûts fixes élevés et des coûts variables bas. Pour amortir ses coûts fixes, le nucléaire est préférentiellement utilisé pour une opération en base inflexible, c’est-à-dire opérer à un niveau constant pour répondre à la partie non variable de la demande d’un système électrique et produire au maximum de sa propre capacité. En raison de cette spécificité, l’insertion de la production nucléaire dans les marchés concurrentiels d’électricité n’a pas été profondément étudiée jusqu’à présent. Par conséquent, même dans des marchés concurrentiels, la question de la gestion optimale d’un parc de production nucléaire n’a pas été soulevée parce que la production nucléaire est censée fonctionner en continu (pour couvrir la demande de base). Cependant, il y a des cas ou` la gestion de la production nucléaire semble plus complexe que ne le suggère cette vision simplifiée. En règle générale, lorsque la proportion de l’énergie nucléaire dans un parc de production est élevée, la production nucléaire doit s’adapter aux variations de la demande. Cela soulève la question de la façon optimale de gérer cette technologie de production dans ce contexte. Comme cette question n’a pas été étudiée jusqu’à présent, il est nécessaire de proposer un cadre théorique qui permet une analyse des situations comme celle de la France, avec un marché concurrentiel et où le nucléaire représente 80% de la production, c’est-à-dire beaucoup plus que ce qui serait nécessaire pour couvrir la demande de base. Nous nous plaçons dans un horizon à moyen terme de la gestion (1 à 3 ans) pour tenir compte de la variation saisonnière de la demande. A moyen terme, le gestionnaire d’un parc nucléaire très large (comme le parc français) doit ajuster sa production selon les variations saisonnières de la demande. Dans ce cadre, le stock de combustible nucléaire peut être analysé comme un réservoir puisque les centrales nucléaires s’arrêtent périodiquement (tous les 12 ou 18 mois) pour recharger leur combustible. La gestion de ce réservoir permet de profils différents d’usages de combustible nucléaire au cours des différentes saisons de l’année. Ainsi, nous nous pencherons sur cette question comme une analyse économique rationnelle de l’opération d’un “réservoir” de combustible nucléaire. Nous allons ensuite l’analyser dans un cadre général déterministe dynamique avec deux types de production : nucléaire et thermique non-nucléaire. Nous étudions la gestion optimale de la production dans un marché parfaitement concurrentiel. Ensuite, nous établissons un modèle numérique (basé sur les données du marché français) où les centrales nucléaires ne sont pas opérées à production constante, mais dans un cadre de placement flexible (comme le parc nucléaire français). […]Nuclear power as a generation technology that is widely used in electricity production systems is characterized by high fixed costs and low variable costs. To amortize its fixed costs, nuclear is preferentially used for inflexible baseload operation, i.e. operate at a constant level to meet the non variable part of electricity demand of a system and produce at its maximum capacity. Because of this specificity, the insertion of nuclear production in competitive electricity markets has not been deeply studied so far. Therefore, even in competitive markets, the question of the optimal management of a nuclear generation set has not been raised because nuclear production is supposed to operate continuously (to cover baseline demand). However, there are cases where the management of nuclear generation seems more complex than suggested by this simplified view. Typically, when the proportion of nuclear energy in a production set is high, the nuclear generation output has to adjust to the variations in demand. This raises the question of the optimal way to manage this production technology in that kind of setting. As this question has not been studied so far, there is a need for a theoretical framework that enables an analysis of situations like the French one, with a competitive market and where nuclear represents 80% of generation, i.e. much more that what would be necessary to cover the baseload demand. We place ourselves in a medium-term horizon of the management (1 to 3 years) to take into account the seasonal variation of the demand level. In the medium-term, the manager of a large nuclear set (like the French set) has to set its seasonal variation of output according to the demand level. Since nuclear units have to stop periodically (from 12 to 18 months) to reload their fuel, we can analyze the nuclear fuel as a stock behaving like a reservoir. The operation of the reservoir allows different profiles of nuclear fuel use during the different demand seasons of the year. Thus, we will look at this question as a rational economic analysis of the operation of a nuclear fuel “reservoir”. We then analyze it within a general deterministic dynamic framework with two types of generation: nuclear and thermal non-nuclear. We study the optimal management of the production in a perfectly competitive market. Then, we establish a numerical model (based on data from the French market) with nuclear plants being not operated strictly as base load power plants but within a flexible dispatch frame (like the French nuclear set). [...]
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Cafiero, Christopher. "What is the effect of deregulation on fuel efficiency in electricity generation?" Connect to Electronic Thesis (CONTENTdm), 2010. http://worldcat.org/oclc/647197710/viewonline.
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Connolly, Jeremiah P. (Jeremiah Peter). "Effect of real-time electricity pricing on renewable generators and system emissions." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/42938.
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Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2008.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 127-130).
Real-time retail pricing (RTP) of electricity, in which the retail price is allowed to vary with very little time delay in response to changes in the marginal cost of generation, offers expected short-run and long-run benefits at the societal level. While the effects of RTP on most market participants have been examined previously, its effects on a) renewable generator revenues and b) power sector emissions are not well understood. This thesis presents a counterfactual model of the new England wholesale power market, including within-hour consumer price response, to analyze revenues under RTP for four renewable test cases and emissions of CO2, SO2, and NOx. Assuming a moderate consumer price-response ( e = -0.3), I find that revenues for both wind and solar cases will decrease by about 3%, a smaller loss than that expected by the generation sector as a whole (~ 6%) or by peak generators ( ~ 55%). In the same scenario, RTP is expected to decrease emissions of CO2, SO2, and NOx by 2-3% in the short-run. These results are qualitatively robust across a range of elasticities and other input parameters. A discussion of the political barriers to RTP highlights interest group pressure from peak generators and the framing of gains and losses for consumers. These barriers are likely to attract significant policymaker attention in RTP discussions, but the results of my empirical analysis show the need to also consider how RTP may interfere with the ability to achieve other policy objectives, including promoting renewable energy and reducing emissions.
by Jeremiah P. Connolly.
S.M.
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Avgerinopoulos, Georgios. "Strategic energy systems analysis:Possible pathways for the transition of electricity sector inTanzania." Thesis, KTH, Energisystemanalys, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-139072.
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This study examines the concept of the evolution of electricity sector in Tanzania.Electrification of Africa has raised large discussion and thus, nine scenarios based ondifferent production pathways and demand projections are formulated. The studyconsiders both grid based centralized electricity and decentralized power production.The main differentiation is between a centralized electricity system and decentralizedpower that are closer to demand. A model is created using three modeling tools(Answer-OSeMOSYS, LEAP and MESSAGE) and the results are presented andcompared. Finally, different funding options for electricity expansion projects inTanzania are explored in order to investigate the feasibility of the scenarios as well asa geopolitical analysis is carried out.
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Mayer-Spohn, Oliver. "Parametrised life cycle assessment of electricity generation in hard-coal-fuelled power plants with carbon capture and storage." Stuttgart IER, 2009. http://d-nb.info/1000306909/34.
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Li, Jiasen. "Prediction of Electricity Price Quotation Data of Prioritized Clean Energy Power Generation of Power Plants in The Buyer's Market." University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1627663082026476.
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Atkinson, R. Dwight. "Corona switching: an osmogene mitigation technique." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/49920.
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Odorous gases such as hydrogen sulfide have long been associated with wastewater treatment plants, especially those with long forced mains which allow septic conditions to develop. With the encroachment of urban and suburban populations, many wastewater treatment plants are no longer located far enough from residential areas to prevent odor problems. This has lead to renewed efforts to develop odor control techniques.
The application of high energy coronas as a means to oxidize odorous gases has been limited by the relatively small size of the corona region around a given charged wire, approximately 1 centimeter at an applied voltage of 35 kilovolts. Attempts to enlarge the effective corona region by spacing wires such that their coronas would overlap have failed due to corona extinction, the destructive interference of the electric fields surrounding adjacent charged wires.
This study demonstrates that corona extinction can be avoided in a system of closely spaced wires flanked by grounded plates if the wires are energized individually instead of' simultaneously. By employing a rapid load-switching technique an essentially continuous corona sheet can be produced.
A bench-scale device utilizing the rapid switching principle was constructed and its ability to remove odorous gases, including hydrogen sulfide, was demonstrated. The influence of parameters such as flowrate, inlet concentration, switching frequency, temperature, and humidity on removal efficiency was evaluated.Ph. D.
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Voss, Joshua. "Forage adaptability trials for forage and seed production in Bolivia : effect of 5 herbicides on 7 native Utah forbs /." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1639.pdf.
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Ramahlape, Khalipha. "Effect of Vee-diagramming on grade 10 township learners understanding of some electrical concepts." Thesis, University of the Western Cape, 2004. http://etd.uwc.ac.za/index.php?module=etd&.
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This study was based on the Scientific and Technology Literacy Project study done between 1996 and 2001. It sought to determine whether Vee-diagramming could help enhance grade 10 township learners understanding of some aspects of electricity. It also sought to find out whether age and gender influenced the learners understanding of these concepts.
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Sangwan, Veena. "Temperature sensing in plants." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37831.
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It is now well established that cold-triggered calcium influx mediates cold-induced gene expression and development of freezing tolerance (cold acclimation). In this thesis, cold signaling events both upstream and downstream of calcium influx were examined.First, it was shown that the studies on calcium mediation of cold acclimation in alfalfa cell suspension cultures could be applied to intact seedlings of Arabidopsis. Calcium chelators and channel blockers caused a strong reduction in the cold-induced accumulation of kin1 and kin2 transcripts, suggesting that calcium influx was an essential event during cold signaling and that the source of calcium for this influx was largely the calcium-rich cell wall. Evidence suggesting the involvement of calcium-dependent protein kinases (CDPKs) was also obtained.
Second, the nature of events upstream of calcium influx was explored. For this study, transgenic Brassica napus seedlings possessing both the endogenous cold-inducible BN115 gene and the coding part of beta-glucuronidase (GUS) gene placed under the control of the BN115 promoter were used. Thus cold-activation of the BN115 promoter drove the expression of both BN115 at the transcriptional level and the GUS enzyme activity at the translational level. Cold-activation of BN115 was inhibited by chemicals which cause membrane fluidization, cytoskeletal stabilization and inhibition of Ca2+ influx, and mimicked at 25°C by chemicals causing membrane rigidification, cytoskeletal destabilization and Ca2+ influx. Inhibitors of protein and lipid kinases prevented cold-activation of BN115, but inhibition of protein phosphatases activated BN115 at 25°C.
Third, given the increasing importance of mitogen-activated protein kinases (MAPKs) in signal transduction, the nature of molecular mechanisms that lead to cold-activation of a previously reported MAPK, SAMK, was investigated. During this study, the first plant MAPK activated by heat shock was discovered and named HAMK (Heat-shock-activated MAPK). It was shown that cold-activation of SAMK is mediated by cold-induced membrane rigidification, whereas the heat shock-activation of HAMK occurs through heat shock-induced membrane fluidization. Whereas activation of both SAMK and HAMK is blocked by an actin microfilament stabilizer, it is mimicked at 25°C by chemical destabilizers of microtubules or actin microfilaments. All of these events are inhibited by blocking the influx of extracellular Ca 2+. Cold-activation of SAMK and heat-activation of HAMK was prevented by treatment of cells with inhibitors of CDPKs. Thus, cold and heat shock are sensed by structural changes in the plasma membrane, which transduces the signal via cytoskeletal rearrangements to the opening of calcium channels, leading to Ca2+ influx, activation of CDPKs and activation of distinct MAPK cascades.
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Gencoglu, Cihangir. "Assessment Of The Effect Of Hydroelectric Power Plants'." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612165/index.pdf.
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The Turkish TSO (TEIAS) has been leading a project that aims the synchronous interconnected operation of the Turkish Power System and the ENTSO-E CESA (former UCTE) System. For this purpose, this study concentrates on the specific problems related to the electromechanical systems of large size hydroelectric power plants regarding low frequency inter area oscillations, which are prone to occur once the interconnected operation is established. The expected frequency of inter area oscillations after interconnected operation is close to 0.15 Hz, which is in the frequency range of the speed governing structures of turbines, as explained in the first two sections of the thesis. In the third section, the nonlinear turbine governor model used throughout the study is explained. In the following part, the governor parameter tuning study with regard to the defined performance objectives is explained. Afterwards, the effect of the retuned governor settings of the sample hydroelectric power plants on a simple multi machine power system is shown. Following that, the system wide effect of removing the sources of negative damping, which are strongly dependent on the governor settings of the major hydroelectric power plants of the Turkish Power System, is shown. In the final part, conclusions are made on the operation of the hydroelectric power plants regarding the frequency stability of the system after synchronous interconnected operation of the Turkish Power System and the ENTSO-E CESA System.
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Lau, Ka Keung. "Effect of Oâ†3 fumigation on nitrate reduction in plants." Thesis, Lancaster University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337586.
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LoÌpez-Chuken, Ulriko J. "The effect of chloro-complexation on cadmium uptake by plants." Thesis, University of Nottingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430615.
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McKee, J. "The effect of temperature on sexual reproduction in flowering plants." Thesis, University of Newcastle Upon Tyne, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360337.
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Wang, Ding Xiang. "Interaction between the effects of sodium chloride and high temperature on the vegetative growth of tomato (Lycopersicon esculentum Mill.)." Title page, contents and summary only, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phw2456.pdf.
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Watts, Frank. "The effect of electrical potential on mass transfer in liquid-liquid extraction." Diss., Georgia Institute of Technology, 1990. http://hdl.handle.net/1853/10283.
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MASSARO, CONCETTA. "THE ROLE OF RENEWABLES ON THE ITALIAN ELECTRICITY MARKET." Doctoral thesis, Università Cattolica del Sacro Cuore, 2017. http://hdl.handle.net/10280/35712.
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Ogni tecnologia produttiva ha un proprio profilo di dispacciamento ottimale che non dovrebbe essere alterato dall’ingresso delle intermittenti tecnologie rinnovabili per mantenere la migliore allocazione di prezzo e quantità. La nostra ricerca si focalizza sul mercato elettrico italiano.
Considerando il comportamento di Edison Trading sul mercato, noi analizziamo se l’incremento di energia rinnovabile porta alla riduzione del prezzo e della produzione di energia grazie all’efficienza. I nostri principali risultati suggeriscono che le rinnovabili hanno un impatto negativo sulle quantità offerte. Gli impianti solari e di pompaggio portano ad un consistente incremento del prezzo elettrico; il contrario vale per le altre rinnovabili.
La nostra analisi sul mercato italiano aggregato considera il comportamento di tutti gli operatori del mercato elettrico (quelli aventi consistenti e limitate quote di mercato) nel quindicesimo giorno di ogni mese nel periodo gennaio 2013 - giugno 2015. Possiamo aspettarci lo stesso risultato in termini di impatto sul prezzo e quantità, data la crescente potenza lorda eolica e solare? I nostri risultati empirici sottolineano che le tecnologie intermittenti possono solamente portare ad incrementi di prezzo, mentre i più grandi operatori di mercato (Enel, Eni ed Edison) utilizzano la tecnologia CCGT efficientemente, poichè producono quando il prezzo è più alto.Each power plant has its own optimal dispatchable profile that should not be altered by the entrance of intermittent renewables to maintain the best allocation of price and quantity. Our research focuses on the Italian electricity market. Focusing on the market behaviour of Edison Trading, we investigate if the increase in renewable energy leads to a decrease in energy price and in energy production due to efficiency. Our main results suggest that renewables have a negative impact on the quantity supplied. Solar and pumped-storage technologies lead to a consistent increase in the electricity price, while the reverse is true for the other renewables. Our analysis on the aggregate Italian electricity market considers the behaviour of all electricity market operators (with low and high market shares) on the 15th day of each month in the period January 2013 - June 2015. Can we expect the same results in terms of the impact on price and quantity, given the increase in gross wind and solar power? Our empirical findings point out that the intermittent technologies can only lead to price increases, whereas the biggest market players (Enel, Eni and Edison) use CCGT technology efficiently since they produce when the price is higher.
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Kachinda-Hofisi, Tapiwa. "Wind Power and the Swedish Electricity Market : An analysis of the impact of wind power production on wholesale electricity prices in bidding area SE3." Thesis, Södertörns högskola, Nationalekonomi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-46171.
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Wind power has been growing rapidly in Sweden over the past decade as the country focuses on 100% renewable energy by 2040. The thesis seeks to investigate if increased wind power has had a dampening effect on the hourly day-ahead spot prices in Sweden’s bidding area SE3. An empirical approach is undertaken to estimate the impact that wind power has had onprices. Hourly spot prices for bidding area SE3 for the years 2016-2019 are analysed using a multivariate regression method. Other important variables like hydropower and nuclear production which are very significant in the Swedish electricity market are controlled for in the study. The results confirm that in the period 2016-2019, bidding SE3 experienced a merit order effect on price caused by increased wind power. The study shows that a 1% increase inwind power production is estimated to have decreased SE3 hourly spot prices by between 0.0268% and 0.059% between 2016 and 2019.
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Verma, Suruchi. "Comparative Analysis of Wind, Solar and Landfill Gases as Alternative Sources of Energy for Electricity Generation." ScholarWorks@UNO, 2010. http://scholarworks.uno.edu/td/1262.
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The document reviews the current and projected electricity demand until the year 2030 along with the fuel mix. Several projections based on different agencies were studied in order to understand the trend of fuel mix projected to be used. Clearly, the fuel mix being used or projected is unsustainable. Depletion of fossil fuels, increasing demand and environmental impacts are some of the factors that emphasize the use of Alternative Sources of Electricity. Three of the upcoming Alternative Sources - Solar, Wind and Landfill Gases - are discussed and compared in the document. Based on the comparison, Landfill Gas projects seem to be very favorable, despite the higher costs related with such projects, several advantages over the other two Alternative Sources are discussed in the document. The several advantages of Landfill Gas projects, such as emissions reduction, better power quality, reduction in transmission losses, and several others are discussed in the document
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Menzies, Greig Hamilton. "An economic evaluation of a wind power electricity generating farm in South Africa." Thesis, Nelson Mandela Metropolitan University, 2011. http://hdl.handle.net/10019.1/18156.
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Thesis (MComm (Economics)--Nelson Mandela Metropolitan University, 2011.ENGLISH ABSTRACT: Renewable energy technology has received much attention over recent years. The depletion of known fossil fuel reserves and the volatility of international fuel prices require that society looks beyond the current coal-dominated electricity generation methods. Wind energy is an internationally well-established technology with large markets in major countries around the world, such as the USA and Germany. South Africa has the potential to generate large amounts of electricity from the wind because of the strength of the country’s wind resource. The long coast line and open areas are ideal for the exploitation of wind energy.
Sponsored by the Centre for Renewable and Sustainable Energy Studies
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Lauer, Markus [Verfasser]. "DBFZ Report Nr. 37: Economic assessment of biogas plants as a fl exibility option in future electricity systems / Markus Lauer." Leipzig : Deutsches Biomasseforschungszentrum gemeinnützige GmbH, 2020. http://d-nb.info/1219519863/34.
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Llovera, Bonmatí Albert. "Market role, profitability and competitive features of thermal power plants in the Swedish future electricity market with high renewable integration." Thesis, Uppsala universitet, Elektricitetslära, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-330392.
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The Swedish energy market is currently undergoing a transition from fossil fuels to renewable energy sources, including a potential phase-out of nuclear power. The combination of a phase-out with expansion of intermittent renewable energy leads to the issue of increased fluctuations in electricity production. Energy-related organizations and institutions are projecting future Swedish energy scenarios with different possible transition pathways. In this study the market role of thermal power plants is assessed in two future scenarios. The fast start-up time of gas turbines means that they can balance out fluctuations. Given that a large share of reports already studies costs of the system, this report instead investigates the profitability, potential market roles, and competitive features of these technologies in the future market.
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Le, Roux Armand. "Opportunity for electricity generation from discard coal at the Witbank Coalfields." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/97416.
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Thesis (MDF)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Coal export mines in the Mpumalanga Highveld region of South Africa generate growing volumes of discard coal estimated to be in excess of a billion tonnes. It presents a significant pollution hazard. Discard coal has a usable carbon content that can be used in the generation of power through the application of fluidized bed combustion technology. The objective of this study was to evaluate its potential as an economically viable fuel source for generation of electricity at the Witbank coalfields. This study was motivated by advances in fluidized combustion technology and significant changes in the South African electricity market in recent years. A holistic approach was adopted considering regulatory policy, market, technical, environmental and economic factors in the use of discard coal as an alternative fuel source. The policy and regulatory environment was assessed from the perspective of the private sector as project developer and the most likely source of funding, given government’s funding constraints. An evaluation of the future pricing structure of electricity, energy resource mix, demand growth, future development of the coal market, production of discard coal and the cost of coal was conducted. Levelised cost of electricity methodology was used to conduct the economic feasibility for comparison with the cost of Eskom’s pulverised coal technology for its new power stations. The study found that generating electricity from discard coal presents a significant commercial opportunity as its levelised cost of electricity was found to be lower than Eskom’s levelised cost of electricity for its new power stations. Plant sizes of 125 MW to 1 000 MW were considered. For plant capacities of about 500 MW and larger, the cost of electricity was found to be competitive with the current average electricity price taking into account the cost of transmission/distribution and interest charges. This is on condition that the electricity is sold to Eskom or wheeled through Eskom’s grid and sold to third parties. Otherwise, plant capacity will be limited to the maximum demand from large local users, which is expected to be considerably less than 500 MW. Currently there is no regulatory certainty on wheeling mechanisms and charges and it is an area where major policy development is required. The development of a project could be hampered by policy uncertainty and because of Eskom’s monopoly position as single buyer. The favourable results and findings of the economic evaluation conducted during this study warrant further detailed feasibility studies.
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Dickinson, Laurie Alan. "Studies of magneto-tunneling into donor states and of the breakdown of the quantum Hall effect." Thesis, University of Nottingham, 2004. http://eprints.nottingham.ac.uk/14393/.
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This thesis describes an experimental investigation and analysis of two topical problems in condensed matter physics: 1.) the effect of a magnetic field on quantum states of an electron bound to a shallow donor impurity in a quantum well heterostructure and 2.) the breakdown of the quasi-dissipationless state of the integer quantum Hall effect. Two introductory chapters describe important material parameters and the experimental equipment and techniques used. Magneto-tunneling spectroscopy (MTS) is used to probe the spatial form of the eigenfunction of electrons bound in the ground state of a shallow Si-donor impurities in a GaAs/(A1Ga)As quantum well. An in-plane magnetic field, B[subscript] |, acts to tune the k-vector of the tunnelling electron through the effect of the Lorentz force. The variation with B [subscript] | of the tunnel current through the donor ground state provides a map of the Fourier transform, |ψ(k)| [superscript]2, of the probability density of the ground state donor wavefunction in real space. By applying a strong magnetic field component, B [subscript] ||, parallel to the direction of tunnel current, it is possible to magneto-compress the donor function in real space. The magneto-compression is investigated using MTS and the data are analysed in terms of a simple model, which is critically discussed. The breakdown of the integer quantum Hall effect is investigated by measuring the variation of the voltage drop Vxx along the direction of current flow for a range of currents and magnetic fields and for a number of sample geometries including Hall bars with narrow channels. The data are discussed in terms of two complementary models of breakdown: the bootstrap electron heating model and magneto-exciton formation at a charged impurity. Evidence is found for both types of breakdown depending on the type of sample used and on experimental parameters. For samples with constrictions, it is found that in the breakdown region the value of Vxx measured across a pair of contacts on one side of the Hall bar can differ substantially from that measured on the other side. A model based on magneto-exciton formation at impurities is proposed to explain this unexpected effect. The thesis concludes with a brief summary and suggestions for future work.
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Mjwara, Jabulani Michael. "The interactive effects of light, temperature and CO₂/O₂ ratios in photosynthesis of Coix lachryma-jobi L." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1003785.
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A portable infra red gas analyzer was used to investigate the interactive effects of light, temperature, and CO,jO, ratios under controlled environmental conditions in an attempt to model gas exchange characteristics of Coix Iachryma-jobi L. Plotting light response curves as a function of temperature (20, 25 30 and 35°C) revealed no sign of light saturation even at a photosynthetic photon flux density (PPFD) close to 2000 !Lmol m-' sol. High net assimilation rates (A) of approximately 24 !Lmol CO, m"s'! were realized at 30-35°C. Assimilation (A) versus internal CO, partial pressure (C,) curves showed a steep rise with increase in C, but saturated at approximately 150 (JLII-!) and all the results, either in the absence or presence of 0" showed a similar response under all temperature regimes. C. Iachryma-jobi exhibited low CO, compensation points cr ) between 0 and 10 JLlI-! under similar experimental temperatures and either at 0 or 21%0,. The slopes of double reciprocal plots of llA versus llCi, were nearly identical and crossed the yintercept at almost identical points under all 0, concentrations. These data indicate first; that there was no apparent 0, inhibition and second; indicated that the apparent inhIbitor constant (K,) for 0, at the site of carboxylation did not change with increase in [OJ from 0 to 21% oxygen. These observations were further confirmed by results obtained from the analysis of apparent carboxylation efficiency (CE, as defined as the slope of response of A to increasing CO,), as no inhibition of A with increase of [OJ occurred. These characteristics were consistent with typical features of C,photosynthesis. The absence of 0, inhibition and low r values indicated that an efficient CO, concentrating mechanism which eliminates photorespiration exists in C. Iachryma-jobi. At the light microscope level, leaf anatomy exhibited typical C, structure viz. bundle sheath with large chloroplasts and this sheath is further surrounded by a radiate Kranz mesophyU cells. Furthermore the anatomical features suggested that C. wchryma-jobi was an NADP-ME species. Stomatal conductance (g,) to assimilation (g,/A) indicated an increase in A with decrease in g" an essential feature of improving water use efficiency (WUE), but one which drastically reduces CO, diffusion rate. The physical lintitation (stomatal lintitation, t) to CO, diffusion under various [0,] and temperatures, but constant PPFD, did not exhibit statistically significant change in t values at either 0 or 21% a, within each temperature regime, however there was a marked decrease in t as the plant approached its optimum photosynthetic temperature.
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Bäckström, Mathias, and Anton Hellberg. "UNDERSTANDING THE PRODUCTION BEHAVIOUR OF COMBINED HEAT AND POWER PLANTS : A mathematical programming approach." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-40020.
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This thesis investigates how combined heat and power plants (CHP) produce electricity, with respect to several external factors including outdoor temperature and electricity prices. The purpose is to develop and evaluate a tool, with the aim to increase the understanding of CHP plants electricity production behaviour. This tool resulted in an optimisation model, developed in Python and using the CVXPY package. The objective of the model is to include a system of production units and optimise the production from these by minimising the production costs, while also considering technical constraints. Inspiration for the model was found from a literature review and from interviews with people working in the CHP sector, where the latter also provided historical production data used for validation. When comparing the modelled yearly electricity production with the historical data for the same year, it was found that the model deviated less than 10 percent for the two real district heating systems where the model was implemented. In conclusion, it is seen that the model behaves similar to the actual plants when looking at the electricity production; however, the behaviour of the model is slightly exaggerated with faster changes in the electricity production. Though, the results show that the developed model can be used to enhance the understanding of how CHP plants produce electricity.
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Anderson, Annette. "The effects of acetolactate synthase (ALS) inhibiting herbicides on the growth, yield, nodulation and nitrogen fixation of selected legumes." Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09pha545.pdf.
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Bibliography: leaves 251-268. The main aim of this thesis is to determine the effects of sulfonylurea residues and in-crop usage of selected ALS-inhibiting herbicides on the growth, yield, nodulation and nitrogen fixation of legumes under alkaline conditions. Reviews literature concerning ALS-inhibiting herbicides, nitrogen fixation and the effects of herbicides on legumes, rhizobia, nodulation and nitrogen fixation; Glasshouse trial investigating the effects of flumetsulam on biomass and nodulation of chickpea; Field trail investigating the effects of sulfonylurea residues and 'in crop' usage of flumetsulam on medic shoot biomass and seed yield and the effects of chlorsulfuron residues and 'in crop' usage of flumetsulam and imazethapyr on chickpea shoot biomass, grain yield and nitrogen fixation; develops methodologies for experiments investigating the effects of ALS-inhibiting herbicides on nodulation of chickpea.
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Vasquez, Padilla Ricardo. "Simplified Methodology for Designing Parabolic Trough Solar Power Plants." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3390.
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The performance of parabolic trough based solar power plants over the last 25 years has proven that this technology is an excellent alternative for the commercial power industry. Compared to conventional power plants, parabolic trough solar power plants produce significantly lower levels of carbon dioxide, although additional research is required to bring the cost of concentrator solar plants to a competitive level. The cost reduction is focused on three areas: thermodynamic efficiency improvements by research and development, scaling up of the unit size, and mass production of the equipment. The optimum design, performance simulation and cost analysis of the parabolic trough solar plants are essential for the successful implementation of this technology. A detailed solar power plant simulation and analysis of its components is needed for the design of parabolic trough solar systems which is the subject of this research.
Preliminary analysis was carried out by complex models of the solar field components. These components were then integrated into the system whose performance is simulated to emulate real operating conditions. Sensitivity analysis was conducted to get the optimum conditions and minimum levelized cost of electricity (LCOE). A simplified methodology was then developed based on correlations obtained from the detailed component simulations.
A comprehensive numerical simulation of a parabolic trough solar power plant was developed, focusing primarily on obtaining a preliminary optimum design through the simplified methodology developed in this research. The proposed methodology is used to obtain optimum parameters and conditions such as: solar field size, operating conditions, parasitic losses, initial investment and LCOE. The methodology is also used to evaluate different scenarios and conditions of operation.
The new methodology was implemented for a 50 MWe parabolic trough solar power plant for two cities: Tampa and Daggett. The results obtained for the proposed methodology were compared to another physical model (System Advisor Model, SAM) and a good agreement was achieved, thus showing that this methodology is suitable for any location.
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Tselepis, Efstathios. "Preparation and study of electro-optical properties of oxide films of silver, copper and their alloys using the photovoltaic effect." Thesis, University of Ottawa (Canada), 1988. http://hdl.handle.net/10393/5473.
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Greyvenstein, Fritz Siegruhn. "Performance prediction for multi-effect distillation (MED) plants / by F.S. Greyvenstein." Thesis, North-West University, 2007. http://hdl.handle.net/10394/855.
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Many countries worldwide experience water shortages on a daily basis and this water
crisis is expected to increase even more in the near future due to limited fresh water resources. Alternative sources of fresh water such as desalinated seawater are becoming an attractive option for many developing countries. Although various desalination technologies exist today, interest in multi-effect distillation (MED) is growing rapidly worldwide. Today various energy power sources are utilized in MED plants, but the use of nuclear power as a clean and effective heat source for the MED process seems to be gaining interest. Implementation of HTGR technology, such as the Pebble Bed Modular Reactor being developed in South Africa is ideal for MED desalination purposes. In these types of reactors high temperature water is available as waste heat as opposed to high temperature steam from conventional steam power plants. Currently conventional MED plants utilize steam as the process heat source, to drive the MED process.
In this study a system simulation model was developed in the computer language C++. It evaluates different MED process flow configurations in order to identify an optimum MED plant configuration for both water and steam as process heat source. Simulation results indicate that a steam-heat-source (SHS) MED plant produces approximately 25-30% more product water than a water-heat-source (WHS) MED plant while utilizing less plant stages. Plant layout and economics are impacted by the available process heat source. Results also indicate that a parallel feed configuration (PFC), which incorporates preheating of feed water, seems to be the optimum process flow configuration type for both the SHS and WHS type plants. Product water costs for optimized SHS and WHS MED plants were also compared. Various system parameters influence plant performance, but the serie effect temperature difference seems to be the most influential parameter in terms of water production. Preheating of feed water increases production levels up to 30%. Results from the C++ model have been compared to results calculated with MEE-TVC, a desalination system design program and were generally in good agreement.Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2008.
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Torp, Mikaela. "The effect of snow on plants and their interactions with herbivores." Doctoral thesis, Umeå : Department of Ecology and Environmental Science, Umeå University, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-30444.
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Ajayi, Victor A. "Essays on deregulation in the electricity generation sector." Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/27614.
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Over that past three decades, power sector reform has been a key pillar of policy agendas in more than half of the countries across the world. This thesis specifically concerns the empirical investigation of the economic performance of the international electricity generation industry. Drawing on the stochastic frontier analysis techniques, the thesis considers the influence of reform as exogenous factors in shifting frontier technology as well as shaping inefficiency function directly -determinants and heteroscedasticity variables. The first essay uses an extensive panel dataset of 91 countries over the period 1980 to 2010 to measure the impact of deregulation on efficiency and total productivity growth using stochastic input distance frontier (SIDF). Three specific issues are addressed in the first essay: (1) the relationship between deregulation and technical efficiency, (2) the extent of the rank correlation of the country intercepts with deregulation via their position on the frontier, (3) the trend of total factor productivity and its components. We establish a positive impact of deregulation on efficiency and some compelling evidence suggesting that the country intercepts equally account for the influence of deregulation aside efficiency. In particular, the technical efficiency index from the first paper reveals that most OECD European countries are consistently efficient. Building on this finding, the second essay investigates the performance in term of cost efficiency for electricity generation in OECD power sector while accounting for the impact of electricity market product regulatory indicators. Empirical models are developed for the cost function as a translog form and analysed using panel data of 25 countries during the period 1980 to 2009. We show that it is necessary to model latent country-specific heterogeneity in addition to time-varying inefficiency. The estimated economies of scale are adjusted to take account of the importance of the quasi-fixed capital input in determining cost behaviour, and adjusted economies of scale are verified for the OECD generation sector. The findings suggest there is a significant impact of electricity market regulatory indicators on cost. Cost complementarity between generation and emissions found to be significant, indicating the possibility of reducing emissions without necessarily reducing electricity generation. Finally, the third essay examines the performance of electric power industry s using consistent state-level electricity generation dataset for the US contiguous states from 1998-2014. We estimate stochastic production frontier for five competing models in order to identify the determinants of technical inefficiency and marginal effects. We find evidence of positive impacts of deregulation on technical efficiency across the models estimated. Our preferred model shows that deregulated states are more efficient in electricity generation than non-deregulated states. The result of the marginal effects shows that deregulation has a positive and monotonic effect on the technical efficiency.
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Ingarfield, Patricia Jean. "Effect of water stress and arbuscular mycorrhiza on the plant growth and antioxidant potential of Pelargonium reniforme Curtis and Pelargonium sidoides DC." Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2794.
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Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2018.Pelargoniums have been studied extensively for their medicinal properties. P. reniforme and P. sidoides in particular are proven to possess antimicrobial, antifungal and antibiotic abilities due to their high antioxidant potential from compounds isolated from their tuberous roots. These plants have now been added to the medicine trade market and this is now causing concern for conservationists and they are generally harvested from the wild populations. This study evaluated the effect of water stress alone and in conjunction with arbuscular mycorrhiza on two species of Pelargoniums grown in a soilless medium. The experiment consisted of five different watering regimes which were applied to one hundred plants of each species without inoculation with arbuscular mycorrhiza and to one hundred plants of each species in conjunction with inoculation with AM. All the plants in the experiment were fed with a half-strength, standard Hoagland nutrient solution at varying rates viz. once daily to pot capacity, every three days to pot capacity, every six days to pot capacity, every twelve days to pot capacity and every twenty-four days to pot capacity. The objectives of the study were to measure the nutrient uptake, SPAD-502 levels (chlorophyll production) and metabolite (phenolics) formation of both species, grown under various rates of irrigation and water stress, as well with or without the addition of arbuscular mycorrhiza at planting out. Each treatment consisted of 10 replicates. SPAD-502 levels were measured weekly using a hand held SPAD-502 meter. Determination of nutrient uptake of macronutrients N, K, P, Ca, Mg and Na and micronutrients Cu, Zn, Mn, Al and B were measured from dry plant material at the end of the experiment by Bemlab, 16 Van Der Berg Crescent, Gants Centre, Strand. Plant growth in terms of wet and dry shoot and root weight were measured after harvest. Determination of concentrations of secondary metabolites (phenolic compounds) were assayed and measured spectrophotometrically at the end of the experiment. The highest significant reading of wet shoot weight for P. reniforme was taken in treatments 1 and 2 with and without mycorrhiza i.e. WF1, WF1M, WF2 and WF2M, with the highest mean found in WF1 with no mycorrhiza. This indicates that under high irrigation AM plays no part in plant growth, possibly due to leaching. More research is necessary in this regard. With regard to wet root weight, this was found to be not significant in any of the treatments, other than the longest roots being found in WF4. Measurements for dry root weight showed that WF1,2,3 and 5 were the most significant at P≤ 0.001 significance, with the highest weight found at treatment being WF3 and WF3M. The highest mean of shoot length of the plants was measured in treatment WF2 at moderate watering, but no statistical difference was found with water application and mycorrhiza addition. Nutrient uptake was increased in P. sidoides in all the different watering levels in the experiment except in the uptake of Mg. AM inoculation showed an increase in the uptake of Ca, while absorption of N occurred at higher water availability. K uptake was enhanced by the addition of AM in high water availability and K utilisation decreased as water stress increased. Medium to low watering resulted in higher leaf content in P. sidoides while the interaction between water availability and AM inoculation increased chlorophyll production towards the end of the experiment.
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Mayer-Spohn, Oliver [Verfasser]. "Parametrised life cycle assessment of electricity generation in hard-coal-fuelled power plants with carbon capture and storage / Oliver Mayer-Spohn." Stuttgart : IER, 2009. http://d-nb.info/1000306909/34.
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Lumbuenamo, Sinsi Dianza 1954, and Sinsi Dianza 1954 Lumbuenamo. "Litter cover effect on soil spectral response." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276620.
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In order to assess the influence of litter cover on soil background spectral response, trays of dry Lehmann Lovegrass (Eragrostis lehmanniana) were used at three different densities (635, 1015, 2815 Kg/ha) over three different soil backgrounds (Whitehouse sandy clay loam, Superstition sand, and Cloversprings loam). After analysis, spectral measurements made with a Barnes Multi-Modular Radiometer revealed that, soil-litter mixtures exhibit an oil like spectral behavior in the (0.45-2.30 m) waveband range. Mulched soils could not be discriminated from bare soils solely on the basis of the spectral response. However, mulched and bare soil spectral responses differed in amplitude depending on the difference in brightness between the bare soil and the litter cover. In addition, the results showed that while an increase of litter cover density on the soil surface decreased RVI, NDVI and PVI predicted greenness, it increased the GVI based greenness for all soils except the Superstition sand where the GVI showed a reversed trend. The PVI increased at low and intermediate litter densities and decreased at higher ones for the Superstition sand.
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Fielder, Andrew Thomas. "The effect of pricing rules on a constrained wholesale electricity market : an agent based approach." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4440/.
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This thesis presents a comparative computational study of the performance of two different pricing mechanisms in a day-ahead wholesale electricity market, where performance is measured as the average level of payments made by the system operator to the generators. It focusses on two key pricing mechanisms: a uniform price based buy-back pricing model, defined as a short run approximation to the market design in Great Britain, and a nodal pricing model based on Locational Marginal Pricing rules. The research uses a game theory based approach for modelling themarket, allowing multiple rounds of the game to be played and statistically reliable results to be obtained. The research develops an agent based simulation of the day ahead markets for both of the pricing mechanisms, and is simulated on a constrained electricity grid. The agents developed for the simulation each represent a generator and are designed to be profit maximising with respect to a parent generation company. Agents employ an evolutionary algorithm in order to create optimised bids for the generation of electricity based on the current market state. Simulations of the market are performed using a styalised 29-Node transmission grid. A series of experiments are performed comparing the performance of the nodal and buy-back pricing mechanisms, under a series of different operating conditions. It is seen in all of the observed cases that the nodal market design averages a higher level of payments to its participants, and the indication is that the agents in a nodal market are able to explore the higher risk strategies more profitably than their buy-back counterparts. This work also highlights the value of creating evolutionary agents that are robust and flexible in analysing market designs. This research demonstrates that the greater the level of competition in a market the more efficiently market participants act. In addition to this the agents competing with a uniform based Buy Back pricing system appears far more restricted by higher levels of competition than their Nodal counterparts.
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Milshyn, Vladyslav. "Modelling the Effect of Photovoltaics and Battery Storage on Electricity Demand : Implications for Tariff Structures." Thesis, Uppsala universitet, Industriell teknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-301407.
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This project examines the implications of the photovoltaic power generation as well as the battery storage systems on the distribution network tariff structures. Different types of existing distribution tariffs were applied to the residential households’ demand patterns. Several scenarios of demand profiles were theoretically investigated. First scenario included households’ consumption under current situation without on-site power production and any storage, second scenario concerned penetration of average size of solar panel installations and the last demand profile with maximum possible size of photovoltaic panels complemented with battery storage use. The distribution tariffs included in the comparison are: power based tariff and two energy based tariffs, one with flat-rate and another with time-of-use structure. Distribution tariffs were normalized with the aim to research the implications of the on-site production and storage use. Normalization factors were used when comparing financial bills from the households under above mentioned scenarios. Energy distribution tariffs have higher potential for households to save on their energy bill with the introduction of the on-site solar power utilization. On the other hand power tariff provides higher incentive for the implementation of the demand response strategies in the households.