In the promotion and development of renewable energy systems, control engineering is one area which can directly affect the overall system performance and economics and thus help to make renewable energies more attractive and popular. For cost effectiveness, ideally the renewable energy industry requires a control design technique which is very effective yet simple with methods that are transparent enough to allow implementation by non-control engineers. The objective of this thesis is to determine if Model Based Predictive Control (MBPC) is a suitable control technique for use by the renewable energy industry. MBPC is chosen as it uses simple and fairly transparent methods yet claims to be powerful and can deal with issues, such as non linearities and controller constraints, which are important in renewable energy systems. MBPC is applied to a solar power parabolic trough system and a variable speed wind turbine to enable the general applicability of MBPC to renewable energy systems to be tested and the possible benefits to the industry to be assessed. Also by applying the MBPC technique to these two strongly contrasting systems much experience is gained about the MBPC technique itself, and its strengths and weaknesses and ease of application are assessed. The investigation into the performance of Model Based Predictive Control and in particular its application in the renewable energy industry leads to two contrasting conclusions. For simple systems with non-demanding dynamics and having a good model of the system, MBPC provides a very good and effective solution. However for more demanding systems with complex dynamics and strong non-linearities, a basic MBPC controller, applied by a non-control engineer, cannot be recommended.

Distributed Generation (DG) is one of the technologies approved by the South African government for the country's generation expansion to meet future load demand and to support economic growth. DGs change the conventional power flow (generation, transmission to distribution) by injecting real and reactive power at distribution voltage levels. The change in the conventional power flow creates complexity in the power system grid planning due to the conversion of the power system from a passive network to an active network. Introduction of bi-directional power flow on the power system can, among other benefits reduce local power demand which opens opportunities for capital investment deferrals on the transmission and distribution sectors. Consequently, DG impact on the transmission and distribution grid planning has been studied by other researchers. However, previous studies evaluated DG integration on a regulated market and assumed a certain level of generation availability during network peaking period. None of the studies have yet evaluated the benefits on an unregulated market using real measured data. Furthermore, SA distribution network expansion is also being planned without incorporating DGs on the network because of unreliability of wind and solar energy and the network operator's inability to influence the size, location and penetration level of DGs. This planning approach forces the network operator to do more to ensure high network strength. This approach can also result in network overdesign and unnecessary capital expenditure due to the potential benefits that can be deduced from DGs. This dissertation therefore aims to investigate whether incorporating future DG integration in distribution network planning can alleviate financial ramifications of grid code compliance requirements. The data used in the simulations was obtained from the distribution network operator and comprises of both real and reactive power values with a sampling time of 60 minutes for a period of a year. Simulations were conducted for both low and high load conditions to cover the extreme ends of the network and the parameters that were assessed are thermal rating, voltage regulation and network grid losses. Results showed that thermal constraints that are expected on the network when DGs are not considered are not evident when DGs are considered. Results further revealed that there are undervoltage improvements on the network when DGs are considered, and this reduces the capital expenditure that would have otherwise been incurred without DGs to result in a grid code compliant network. Furthermore, there is evidence of reduction in losses under high load conditions and increase in losses under low load conditions in the simulation results. Reduction in losses is caused by supplementary generation from wind and solar plants while increase in losses is due to excessive generation from wind plants which necessitate transportation over long distances to the nearest load centres. In addition to location, size and penetration levels as described in the literature, technology selection for a particular load type is also of utmost important to maximise the DG benefits on the network.

The aim of the master’s work is to assess the wind-power development prospects andproceeding therefrom assume scenarios of the wind-power development in Belarus until 2020 reasoning from the situations and tendencies common to both the national and world powerindustry. In my master’s work I have referred to ХХI-century current problems: procuring energypreparedness of the Republic of Belarus and reducing the anthropogenic impact on thebiosphere and reducing impact on the climate. For Belarus characteristic is a variety ofenvironmental challenges. For instance, one of the most urgent problems is Chernobyldisaster aftermath which affected Belarus to a very great extent. In my opinion some of these global problems may be partially solved by way of usingalternative energy sources, specifically the wind-power engineering. Such a narrow enough notion as the prediction of the wind-power engineering development inBelarus is described in my work by way of so deep and wide analysis of issues dealing withthe wind-power engineering development and prediction: the encyclical analysis of the stateand development of the power industry in its entirety in Belarus and how to reach energypreparedness at the time when effects of the finance-and-economic crisis are currently addedto other negative factors. It has been done specially for the purpose of making such an accurate prediction as possiblehaving analyzed the whole range of interrelated problems. I pitched upon the prediction of the development of the wind-power engineering preciselyuntil 2020 since I’d like to be tied to the basic document: “the National Strategy ofSustainable Social-and-Economic Development of the Republic of Belarus for a Period until2020”. In my work I have analyzed a possibility and horizons of developing the power industry inBelarus based on sustainable development principles. I have proved a capability andprofitability of developing renewable energy sources in Belarus. And the main emphasis wason considering the wind-power engineering. For Belarusian conditions there has beenproposed an optimum alternative of the integrated approach to developing the wind-powerengineering, i.e. joint using the wind-power engineering with other renewable and exhaustibleenergy sources. In this manner there has been refuted an opinion generally held that the windpower engineering development in Belarus is prospectless. In so doing the author, prior to turning to a major issue of the work: the prospects ofdeveloping the wind-power engineering in the Republic of Belarus, has given an estimate ofworld reserves of fuel resources and drawn up the following conclusions: deposits of fossilfuels are depleting and, consequently, the cost of mining operations will grow. Due to the factthat the main extraction of power resources is shifted to extreme regions the cost of conveying energy products is growing. Belarus has to import deficient power resources. Recently the price for Russian energy products for Belarus has grown dramatically. I have also approached the issue of expediency of building an atomic power station in Belarus. The prospects and consequences of using unconventional renewable energy sources in theRepublic of Belarus (with no wind-power engineering) are considered in all their aspectsfollowed by a detailed consideration of the prospects of developing the wind-powerengineering in the Republic of Belarus. Based on the above data there have been proposed two scenarios of developing the wind power engineering in Belarus: Scenario 1 «Unsustainable» and Scenario 2, which I called «Middle way to sustainable energy engineering». / Syftet med magister-arbetet är att bedöma vindkraftverkens utvecklingsmöjligheter och därifrån anta scenarier för vindkraftutvecklingen i Vitryssland till 2020, genom resonemang från de situationer och tendenser som är gemensamma för både nationella och internationella kraftindustrin. I mitt magister-arbete har jag hänvisat till 2000-talets nuvarande problem: att skaffa energisäkerhet i Republiken Vitryssland, minska effekterna av mänsklighetens påverkan på biosfären och minska påverkan på klimatet. Vitryssland kännetecknas av en rad olika utmaningar på miljöområdet. Till exempel är en av de mest akuta problemen Tjernobylkatastrofens efterdyningar som påverkade Vitryssland i mycket stor utsträckning. Min åsikt är att en del av dessa globala problem kan delvis lösas genom att använda alternativa energikällor, särskilt vindkraft-tekniken. Ett sådant specifierat begrepp som förutsägelsen av vindkraftteknikens utveckling i Vitryssland beskrivs i mitt arbete i form av en djup och bred analys av frågor som handlar om vindkraftteknikens utveckling och prognoser: Analysen av läget och utvecklingen av kraftindustrin i sin helhet i Vitryssland och hur man når energi-säkerhet när effekterna av finanskrisen för närvarande läggs till andra negativa faktorer. Det har gjorts speciellt för att göra en sådan precis förutsägelse som möjligt genom att ha analyserat hela raden av sammanhängande problem. Jag fokuserade på prognoser om utvecklingen av vindkraft-teknik innan 2020 eftersom jag vill vara bunden till det grundläggande dokument: ”den nationella strategin för hållbar socialoch ekonomisk utveckling i Vitryssland under en period fram till 2020”. I mitt arbete har jag analyserat en mängd olika möjlighet för att utveckla kraftindustrin i Vitryssland som bygger på principerna för hållbar utveckling. Jag har visat att det går att utveckla förnybara energikällor i Vitryssland, som är både kapabla och lönsamma. Med sikte på att använda sig av vindkraft-tekniken. För de vitryska förhållandena har det föreslagits ett optimalt alternativ för den integrerade strategin för att utveckla vindkraft-tekniken, dvs gemensamt med hjälp av vindkraft-teknik och med andra förnybara och icke förnybara energikällor. På detta sätt har det finns det en allmän åsikt angående vindkraft-teknikens utveckling i Vitryssland, som säger att det inte finns några direkta förutsättningar för denna typ av energi. Därigenom har författaren, innan upptagandet av huvud frågan i arbetet:,utsikterna att utveckla vindkraft teknik i Republiken Vitryssland, gjort en beräkning av världens reserver av bränsle-resurser och kommit fram till följande slutsatser: depåerna av fossila bränslen håller på att ta slut och därmed kommer kostnaderna för utvinning att växa. På grund av det faktum att huvuddelen av utvinningen av bränsle flyttas till extrema regioner så kommer kostnaden för att tillhandahålla energiprodukter växa. Vitryssland måste importera bristfälligt bränsle. Nyligen har priset för ryska energiprodukter för Vitryssland ökat dramatiskt. Jag har också tagit upp frågan om lämpligheten av att bygga ett kärnkraftverk i Vitryssland. Förutsättningarna och konsekvenserna av att använda okonventionella förnybara energikällor bedömning av möjligheterna att utveckla vindkraft tekniken i Vitryssland. Baserat på ovanstående data har det lagts fram två scenarier för utvecklandet av vindkrafttekniken i Vitryssland: Scenario 1 «Ohållbart» och Scenario 2, som jag kallade «Vägen mellan hållbar energi-teknologi».

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Il concetto di rete dell'informazione può diventare uno schema logico con cui descrivere l'evoluzione delle politiche sulle energie rinnovabili e sulla sostenibilità? La ricerca è stata svolta analizzando l'architettura delle due reti (internet e reti energetiche) e l'evoluzione del bene prodotto e distribuito nella rete energetica, l'energia, esplicitando l'accessibilità da parte della distribuzione mondiale delle risorse petrolifere tradizionali e delle risorse rinnovabili. La struttura metodologica del progetto di ricerca si basa due tipi di analisi teorica: 1) l'analisi della nascita delle società in rete attraverso le teorie di Manuel Castells (concetto di spazio di flussi) e di Saskia Sassen e l'evoluzione delle città (cap.2 e cap.5) 2) le analisi dei flussi dei materiali e delle energie avendo come riferimento metodologico l'approccio ecologico ideato dai ricercatori dell'istituto per il Clima, l'Ambiente e l'Energia di Wuppertal, Germania (cap.3 e cap.4) La contraddizione tra città innovative e città che sono ai livelli di enormi discariche o di baraccopoli è esposta nel cap.6 attraverso casi studio e progetto dei Programmi Europei. Nell'ultimo capitolo (cap.7) si riassumono le ipotesi di partenza e i risultati della ricerca e si espongono le questioni aperte. / Can internet logic scheme be used as a basis to describe public policies evolution on renewable energies production and sharing in urban areas all over the world? The research project analyses the two networks (internet and energetic grids) architectures in actual and future urban areas. This analysis is connected with present and future forecasts energy productions from traditional fuels and from renewable sources. Theoretical analysis is conducted following a double conceptual pathway: - societal networks (Manuel Castells theory) and urban areas evolution (Saskia Sassen and Mike Davis) in order to picture the evolution of cities and towns in modern economies and in developing countries (Chapters 2 and 5); - Material and Energy Flow Analysis (approach by Wuppertal Institute for Climate, Environment and Energy) applied to renewable energy (Chapters 3 and 4) In Chapter 6 case studies are exposed on the deep cleavage between two different worlds: innovative, rich towns on a side and the landfills cities, slums on the other side. In the last part hypothesis and thesis are put together and open questions are explained (Chapter 7).