<p> This thesis attempted to synthesize biodiesel using indigenous materials and simple aboriginal techniques. Biodiesel requires plant oil, an alcohol and a catalyst. Coconut oil was extracted using the unrefined method and a 15% yield was obtained. Palm trees can produce ethanol when its palm juice is collected and is fermented to make palm wine. The distillation of palm wine separated an ethanol-water mixture with 35 wt% ethanol content. Calcium oxide, obtained from eggshells, is a catalyst that speeds up the transesterification reaction. Wasted eggshells undergo a calcinations process where calcium carbonate decomposes into calcium oxide and carbon dioxide. A scanning electron microscope confirmed the calcinations at the surface of the eggshells. The Fourier Transform Infrared Spectroscopy analysis of each step confirmed biodiesel synthesis. The successful creation of biodiesel from coconut oil, ethanol and calcium oxide creates a potential for people in small tropical rural villages to empower themselves with just local abundant resources.</p>

<p> With the increasing attention and support behind plug in hybrid electric vehicles, research must be conducted to examine the impacts of vehicles on electric distribution and transmission systems. This research aims first to model the behavior of vehicle battery chargers during system disturbances and mitigate any impacts. A distribution test system example is modeled and several different vehicle charger topologies are added. Faults are applied to the distribution system with vehicle chargers connected and the results are examined. Based on these results, a control strategy to mitigate their negative impacts is suggested. Photovoltaic panels are then added to the system and the study is repeated. </p><p> Several services that plug in hybrid electric vehicles are capable of providing to the electric system are presented in order to allow electric vehicles to be seen as an asset to electric systems rather than a burden. These services are particularly focused on an electric system such as might be found on a college campus, which in this case is represented by the Clemson University electric distribution system. The first service presented is dynamic phase balancing of a distribution system using vehicle charging. Distribution systems typically face problems with unbalance. At most large car parks, a three phase electric supply is expected even though current standardized chargers are single phase. By monitoring system unbalance and choosing which phase a vehicle is allowed to charge from, unbalance between phases is reduced in a distribution system. The second service presented is a decentralized vehicle to campus control algorithm based on time of use rates. Using time of use electricity prices, discharging vehicle batteries during high prices and recharging at low prices is explored. Battery degradation as well as limits placed by required vehicle range availability are included in the decision on whether to charge or discharge. Electric utilities will also benefit from a reduction of load at peak times if vehicles discharge back to the campus. A comparison with stationary battery energy storage is included.</p>

<p> The island of Puerto Rico, a commonwealth of the United States of America, has a population of 3,725,789 according to the 2010 census, and generates 11,100 tons daily of waste. In the Island, landfilling is the dominant form of waste disposal. Most municipal solid waste landfills (MSWLF) in Puerto Rico are a principal source of land, water, and air pollution. In addition, the scarcity of appropriate land to open new landfill facilities make this type of waste disposal an unsustainable form of waste management for the Island. </p><p> This study evaluated the current situation of the MSWLFs in Puerto Rico and the geographic limitations of continuing with this type of waste disposal on the Island. As alternatives to this problem, the principal waste-to-energy (WTE) technologies, combustion and gasification, are evaluated as environmentally responsible forms for disposal of non-recycled waste. </p><p> The evaluation methodology used is based on a multi-criteria decision-making model that uses a subjective rank-order weighting method. Evaluation of WTE technologies is performed by comparing dissimilar indicators in five interest areas: technical, economic, environmental, socio-political, and risk. The methodology is composed of two-components: an expert survey and data analysis. </p><p> An evaluation of the environmental interest area was performed to assess which of the WTE technologies studied herein, combustion or gasification, is more environmentally responsible. In addition, using the relevant scores in different interest areas, they were evaluated to determine the economic benefits of these WTE technologies as viable waste management alternatives for Puerto Rico.</p><p>

Sektorn bostäder och service står för nära 40 % av Sveriges totala energianvändning. Inom denna sektor står hushåll och lokaler för ungefär 90 % av energianvändningen. Det finns stora möjligheter till besparingar i byggnader genom energieffektivisering.Syftet med projektet är att ta fram förslag på åtgärder som på ett kostnadseffektivt sätt kan minska byggnadens energianvändning.Energiberäkningsprogrammet BV2 har använts för att bygga upp en modell av byggnaden. Den simulerade modellens energianvändning jämförs sedan mot uppmätta värden på energianvändningen för att se hur väl modellen stämmer överens med verkligheten.När dessa stämmer överens övergår arbetet till att undersöka olika energieffektiviseringsåtgärder. Simuleringar utförs för åtgärder som installation av värmeväxlare, tilläggsisolering av vindbjälklag och byte av fönster etc.Av de åtgärder som har undersökts har installation av roterande värmeväxlare den kortaste återbetalningstiden på ungefär 3 år, vätskekopplad värmeväxlare hamnar aningen högre med en återbetalningstid på 3,5 - 4 år. Tilläggsisolering av vindbjälklag har en återbetalningstid på runt 5,5 - 6,5 år vid en tjocklek på 350 mm. Denna åtgärd är, efter installation av värmeväxlare, den mest lönsamma och är även relativt enkel att utföra.Utifrån de simulerade åtgärderna har ett åtgärdspaket tagits fram och undersökts med Beloks internräntemetod. Resultatet för hela åtgärdspaketet ger en internränta på 18,7 % och en återbetalningstid på 5 år. Detta överstiger avkastningskravet på 7 % med god marginal. / The housing and service sector accounts for close to 40 % of Sweden's total energy use. In this sector, households and premises account for about 90 %. There are great potential for savings in this sector through energy efficiency.The purpose is to develop proposals for measures that reduce the energy use of the building in a cost-effective manner.The energy calculation program BV2 has been used to build a model of the building. The energy use of the simulated model is compared to the buildings measured values of energy use to see how well the model represents the building in terms of energy use.When these are in agreement, different energy efficiency measures are investigated. Simulations are performed for measures such as installation of heat exchanger, additional insulation of the attic and replace of windows etc.Of the measures investigated, installation of rotary heat exchangers has the shortest pay-back time of approximately 3 years, liquid-coupled heat exchangers get higher with a repayment period of 3,5 - 4 years. Additional insulation of wind bellows has a repayment period of around 5,5 to 6,5 years at a thickness of 350 mm. This measure, after installing heat exchanger, is the most profitable and is also relatively easy to perform.Based on these simulated measures, a package of measures has been developed and investigated using Belok's internal rate method. The result for the entire package of measures provides an internal rate of 18,7 % and a pay-backperiod of 5 years. This exceeds the 7 % yield requirement with a significant margin.

<p> The direct capture of solar heat is now commercial for electrical generation at 550 &deg;C (1000 &deg;F), which has provoked interest in solar driven approaches to commodity and fuels production at higher temperatures. However, conventional commodity and fuels facilities often operate continuously regardless of weather and nighttime conditions. Conversely, direct sunlight is immediately lost upon shading by clouds and sunset. Beyond inconvenience, this intermittency has the potential to destroy high temperature equipment through thermal fatigue and thermal shock. To overcome interruptions in solar availability we propose the inclusion of direct sunlight in commodities and fuels production as a supplement to conventional electrical heating. Within this regime conventional utilities are ideally sourced from sustainable stored or orthogonal energy sources. Control is needed to substitute solar, which can be lost within seconds during transient weather, with electrical heat. To explore control strategies for the alternation of solar and electrical heat a new facility was constructed at the University of Colorado, Boulder. Specifically, a 45 kW 18 lamp high-flux solar simulator was erected that approximates the sunlight found in actual concentrated solar plants. Calorimetry was analyzed for the measurement of extreme radiance in this testbed. Results from calorimeter design were applied to radiation measurement from the lamps, which were capable of delivering 9.076&plusmn;0.190 kW of power to a ?10 cm target with a peak flux of 12.50 MW/m² (12,500 &ldquo;suns&rdquo;). During this characterization a previously unknown observer effect was seen that differentiates radiative heat from lamps and the energy delivered by sunlight in actual concentrated solar facilities. This characterization allowed confident experimentation within the lamp testbed for control studies on a 15 kW solar-electric tube furnace for commodities and fuels production. Furnace electric heat was manipulated by four different linear control strategies for the rejection weather transients reproduced by the high-flux solar simulator lamps. These included feedback, feedforward feedback, model predictive control, and model predictive control with a weather forecast. It was found that model predictive control with a forecast best maintained furnace conditions. Prior researchers have suggested that forecasts would be useful in solar control, which was shown across simulation and experiment.</p><p>

Vid design och projektering av nya byggnader är det ytterst viktigt att ta hänsyn till det resulterande inomhusklimatet. En dåligt optimerad värmning av en bostad på vintern eller en otillräcklig kylning under sommaren kommer att leda till ett missnöje hos de boende vilket så klart vill undvikas. Detta arbete har undersökt hur olika kyllösningar skulle påverka inomhusklimatet i en radhuslänga i Växjö vid namn Solallén. Med hjälp av simuleringsprogrammet IDA ICE och tekniska data från projekteringen av bostäderna har slutsatser dragits om det termiska klimatet och huruvida de olika lösningarna är tillräckliga eller ej. Resultatet kan summeras enligt följande: -Den projekterade kyllösningen med ett kylbatteri kopplat till tilluften kommer inte att vara tillräckligt för att hålla ett lågt missnöje hos de boende under de varmaste sommardagarna.-Det bergvärmesystem som är installerat innefattar golvslingor som kan användas för värmning på vintern men även för kylning på sommaren.-Kylning via golvslingorna kommer att väsentligt höja kvalitén på inomhusklimatet, bl.a. genom att sänka den operativa temperaturen över hela dygnet.-Den procentuella delen av sommaren då den operativa temperaturen ej är godtagbar sjönk från 21.5% med kylning via tilluften till låga 3.2% vid utnyttjande av golvslingorna.-Vid utnyttjande av golvslingorna för kylning av boendet kan bostaden i detta avseende klassas med den högsta nivån för lågenergibyggnader.-Bostäderna kommer med all sannolikhet att uppfylla kraven för nollenergihus på sommarhalvåret, då de solceller som finns monterade kommer att täcka det energibehov som finns. Rekommendationerna är alltså att utnyttja den resurs som finns tillgänglig i form av golvslingor, då tilluften inte kommer att vara tillräcklig. Slutligen bör ytterligare undersökningar genomföras för att jämföra de projekterade värdena med de verkliga efter att byggnaderna är färdiga.

<p> Increased share of Renewable Energy Sources (RES) in the generation mix requires higher flexibility in power system resources. The intermittent nature of the RES calls for higher reserves in power systems to smooth out the unpredictable power fluctuations. Grid-tied energy storage systems are practical solutions to facilitate the massive integration of RES. The deployment of Battery Energy Storage Systems (BESS) on the power grids is experiencing a significant growth in recent years. Thanks to intensive research and development in battery chemistry and power conversion systems, BESS costs are reducing. However, much more advancements in battery manufacturing as well as additional incentives from the market side are still needed to make BESS a more cost-effective solution. Planning and operation of the BESS significantly influence its profitability. It is quite important to find optimal sizes of batteries and inverters. Sizing of the BESS for two different applications is addressed in this work. In the first application, the BESS is co-located with Pumped Storage Hydro (PSH) to meet the Day-Ahead (DA) schedule of wind generation. In the second application, a method for BESS sizing in the presence of PV-induced ramp rate limits is proposed. In this thesis, two methods based on Receding Horizon Control (RHC) for the optimal operation of the BESS are introduced. A co-located BESS and wind farm is considered in both methods. In one method, electricity market participation is not considered, and the goal is solely meeting the DA schedule utilizing the BESS. A novel predictive control method is proposed in this part and the efficiency of the method is evaluated through long-run simulations using actual historical wind power. </p><p> In the second scenario, market participation of the BESS is taken into account. The deviation from the DA schedule can be compensated through the BESS, or by purchasing power from the real-time electricity market. The optimization problem based on physical and operational constraints is developed. The problem is solved through an RHC scheme while using updated wind power and electricity price forecasts. In this thesis, a Ridge-regression forecast model for electricity price and an ARIMA forecast model for wind power are developed. Simulation results using actual historical data for wind power and electricity price demonstrate that the proposed algorithm increases the average daily profit. In order to evaluate the impact of the BESS lifetime and price on average daily profit, different scenarios are defined and simulated. Although they increase the complexity of the problem, much more realistic result might be obtained when all details and constraints are considered. </p><p>

The purpose of this thesis is to examine the possibilities to incorporate solar heat and thermal energy storage to a newly produced apartment block with a low energy use. From HFAB we were given the block “Jordmåen” in Halmstad. “Jordmåen” that was complete in 2015, consists of 4 apartment buildings and fills its need of 669 MWh of thermal energy withdistrict heating. The thesis describes a theoretical study about solar heat and thermal energy storage. To establish a usable area for the solar panels, measurements of an actual building have been made, given to us by HFAB. We use actual data from the Buildings but with the assumption that the buildings aren’t built. Solar panels from ASV Solar are used in the measurements, and possible energy production has been calculated with the program PVGIS. The economic calculations are based on two methods, Pay-off and value approach. “Jordmåen” would be able to cover its heating needs from April to September and provide an addition of thermal energy for the remaining months, with 932 m2 of solar panels connected to a borehole thermal energy storage (BTES) with a degree of efficiency of 65 %. The payoff time for this system varies between 9 to 14 years, and the present worth varies between - 1 027 281 kr and - 22 343 kr, with the best outcome in a scenario with roof integrated solar collectors because of the savings of expensive roof material. The conclusion is that solar heat combined with heat storage is not a profitable investment when not using the full capacity of the thermal heat storage. Although some parameters are missing to establish the real profit we advise to do a more in-depth investigation to get a more accurate outcome.

El är en färsk vara, vilket innebär att det ständigt måste vara i balans mellan produktion och konsumtion. Vid tillfällen då det exempelvis blåser mycket och behovet av el är litet, blir det ett överskott av el. Detta överskott skulle kunna nyttjas till att lagra energi till perioder då behovet är större. Detta med hjälp av pumpkraftverk. Skellefteå Kraft AB vill undersöka möjligheten till att investera i ett pumpkraftverk i Sädva. En kraftstation med en produktion på ca. 117 GWh per år. Det finns två olika sätt att använda sig av pumpkraft, det ena är att använda en separat pumpenhet och det andra är att använda sig av en vändbar turbin. En vändbar turbin har något lägre verkningsgrad än en vanlig vattenturbin på grund av att den ska fungera både som pump och turbin.  De lösningar som analyserats i denna rapport är en separat pump, en vändbar turbin med samma varvtal och ökade dimensioner som dagens turbin och en vändbar turbin med samma dimensioner och ökat varvtal. Det finns många olika sätt att pumpa vatten. I detta projekt har sex olika alternativ undersökts, pumpa nattetid mellan 02-04 och 23-05, pumpa under marsmånad, pumpa när elpriset är under 20 öre/kwh, de 25\% med lägst elpris samt under stopptid.  För att analysera inkomster och produktion har data från tidigare år använts. Alla lösningar gav en större produktion men däremot är netto inkomsten densamma som tidigare, då pumpningen kostar mer än vad man får ut vid produktion av samma mängd vatten. Den lösning som gav bäst resultat är en vändbar turbin med samma varvtal, där ligger återbetalningstiden på mellan 4-5 år. Rekomendation gällande investering är att inte bygga om Sädva kraftstation till ett pumpkraftverk, om syftet är att tjäna mer pengar. Däremot kan ett pumpkraftverk vara bra för att säkerhetställa vattennivån i magasinet. Det optimala pumpsättet är inte funnet, men detta alternativ skulle kunna leverera bättre inkomster och bör därför analyseras mera. / Electrical power is perishable which means that it constantly needs to be balance between production and consumption. At times when it, for example is windy and the need for electricity is low, it will be a surplusr of electrcity. This surplus could be used to store energy for periods of time when the demand is higher. This could be done with pumped-storage hydroelectricity. Skellefteå Kraft AB wants to investigate the possibility of investing in a pumped-storage hydroelectricity plant in Sädva. A power station with a production of approximately 117 GWh per year. There are two different ways to use pump-storage, one way is to have a separate pump unit and the other is to use a reversible turbine. A reversible turbine has slightly lower efficiency than a regular water turbine since it is supposed two work both as pump and turbine. The solutions analyzed in this report are a separate pump, a reversible turbine with the same speed and increased dimensions as today's turbine and a reversible turbine with the same dimensions and increased speed. There are many different ways to pump water. In this project six different options are examined, pumping nightly between 02-04 and 23-05, pumping during month of March, pumping when the price of electricity is under 20 öre/kwh, the 25% with lowest price of electricity and during stop time. In order to analyze revenue and production, data from previous years have been used. All solutions yielded a larger production output, but net income is the same as before, thats because pumping costs more than is expected when producing the same amount of water. The best-performing solution is a reversible turbine with the same speed, with a repayment period of between 4-5 year. Recomendation on investment is not to convert Sädva power station into a pumped-storage hydroelectricity, if the purpose is to earn more money. However, a pumped-storage hydroelectricity can be good for securing the water level in the magazine. The optimal pumping method is not yet found, but this option could maybe deliver better income and should therefore be analyzed more.

Inom Bolidens industriella nät förekommer övertonsströmmar med sådan amplitud att de förorsakar en övertonshalt i spänningen av 12%. Inom nätet finns ett stort antal olinjära laster som kan vara orsak till förekomsten av dessa övertonsströmmar, dessutom finns faskompenseringsutrustning ansluten vilket sannolikt orsakar förstärkning av övertoner genom resonans. För att kartlägga utbredningen av övertoner inom Bolidens industriella nät så utförs mätningar vid fyra olika driftfall. Inledningsvis görs omfattande mätningar vid normal drift vilket ger en tydlig överblick av problemet i dagsläget. därefter utförs mätningar på strategiska platser i nätet i samband med att kondensatorbatterierna kopplas bort. Avsikten är då att undersöka om faskompenseringsutrustningen ingår i en resonanskrets som påverkar övertonsströmmarna i nätet. Slutligen genomförs en mätning under tiden som kvarnarna i anrikningsverket tas ur drift för reparation och underhåll samt ett antal mätningar under tiden som dessa står stilla. När resultatet från dessa mätningar sedan vägs samman så kan man se att det sannolikt är så att de fyra kvarnarna vid anrikningsverket, vilka regleras med hjälp av frekvensomriktare, genererar stora övertonsströmmar. En övervägande stor andel av problemens ursprung kan alltså avgränsas till ett litet antal maskiner. Mätningar indikerar dessutom att övertonsströmmarna förstärks genom resonans till följd av de kondensatorbatterier som finns anslutna till nätet. Slutligen visar också resultatet att övertonshalten inom nätet är så stor att störningar fortplantar sig till överliggande nät och vidare till intilliggande nät. Eftersom övertonsströmmar kan förorsaka haverier i roterande maskiner, transformatorer och kondensatorbatterier så undersöks om sådan risk föreligger. Enligt beräkningar så kan transformatorn som utsätts för de största övertonsströmmarna endast belastas till 95,5% av märkeffekt under rådande omständigheter. Denna drivs dock i dagsläget vid en mycket lägre belastning varpå inga risker bedöms föreligga. Kondensatorbatterierna utsätts för stora övertonsströmmar. Mätningarna visar också att dessa ingår i en resonanskrets varpå det finns en risk för överbelastning och haveri. I anrikningsverket finns en 630kW motor ansluten till nätspänning. Denna utsätts för stora övertonsströmmar vilket förorsakar ökade förluster i lindningar och järn men eftersom inte heller denna drivs vid märkeffekt så anses ingen risk för överbelastning föreligga. När det gäller roterande maskiner kan dock slitage till följd av övertonsströmmar förekomma utan att maskinen överbelastas och här kan ytterligare undersökningar vara motiverade. I dagsläget finns planer på att installera nya kondensatorbatterier med övertonsfilter i nätet vilket med stor sannolikhet minskar övertonshalten i enlighet med vad mätningarna visar. Mätningarna visar dock också att mer högfrekventa övertoner i spänningen ökar kraftigt när kondensatorbatterierna kopplas bort vilket kan behöva beaktas vid val av filter. Ett antal alternativa eller kompletterande lösningar till övertonsproblematiken finns i rapporten. / Inside the industrial grid located in Boliden the presence of harmonic current is so high that It causes a total harmonic distortion of 12% in the voltage.  There is a large number of non-linear loads that can cause this distortion connected to the grid, furthermore there is phase compensating equipment connected that may enhance harmonic currents due to resonance. To investigate the cause and the consequences of harmonics in the grid measurements are conducted during four different modes of operation. Initially a large number of measurements are performed during normal operation to show the harmonic distribution. Then measurements at strategic places in the grid are performed while the phase compensating equipment is disconnected with the objective to show if this equipment is part of a resonance circuit. Finally, measurements are performed while the mills in the dressing plant are taken out of production and additional measurements while they are at standstill. The results of all these tests show that there is a high probability that the four mills at the dressing plant, regulated by inverters, causes large harmonic currents. A predominantly large portion of the harmonic current sources has been isolated in a small number of loads. The result also show that these harmonic currents are enhanced by resonance between the phase compensation equipment and inductive elements of the grid. The resulting distortion is of such gravity that it propagates to adjacent grids via the main grid. Since harmonics can cause breakdowns in rotating machinery, transformers and phase compensating equipment, the risk of this is investigated. Calculations show that at current levels the transformers connecting the industrial grid to the main grid can only be operated at 95,5%. The transformer is currently operating at a far lower rate and no risk of damage is at hand. The phase compensation equipment is exposed to large harmonic current. They are also part of a resonance circuit and the assessment is that they are at risk of breakdown. In the dressing plant, there is a 630kW induction motor connected directly to the grid. This motor Is subjected to large harmonic currents causing losses in copper wiring and the iron core but since this machine runs below rated power the assessment is that this does not put it at risk of breakdown. However, there are other ways that a machine of this kind can be damaged due to harmonics and further investigation into this may be warranted. There are plans of installing new, filtered, phase compensating equipment to the grid which most likely will reduce the harmonic content in accordance with the measurements in this report. However, the measurements also show that higher frequency harmonics in the voltage are enhanced when the phase compensation is disconnected, this may have to be taken in to account when the filters are designed. A number of alternative or additional solutions to the harmonic problem is presented in the report.