Phase change materials are used in many applications to work as thermal energy storage systems. One way to transfer the heat is by letting water flow through a finned pipe submerged in i tank filled with PCMs. This model is analyzed with a finite element difference  based numerical software. The power ratio between using single-PCM and multi-PCMs is compared. The hypothesis was that a multi-PCM configuration is more efficient than a single. The results show that a multi-PCM configuration is more efficient than a single-PCM configuration. It however also indicates that it is of great importance to chose the right temperature span of PCM temperatures to achieve as high power performance as possible. This is recommended for further studies. / Fasväxlingsmaterial (Phase Change Material, PCM) används i många sammanhang för att lagra energi vid konstant temperatur. Ett sätt att överföra värmen är att låta vatten flöda genom ett flänsat rör nedsänkt i en tank fylld med PCM. Denna modell analyseras med en FEM-baserad numerisk mjukvara. Studien jämför den utvunna effekten ur en modell med endast ett PCM, med effekten utvunnen ur en modell med tre olika PCM. Hypotesen var att ett system med flera material var bättre än ett system med endast ett för att erhålla maximal effekt.   Resultatet visar att en modell med flera PCM är effektivare än en modell med endast ett. Det indikerar betydelsen av vilka temperaturer av PCM som väljs för att uppnå så hög effekt som möjligt. Detta område rekommenderas för fortsatta studier.

Under de senaste åren har intresset för förnyelsebara energikällor ökat och den installerade effekten solcellsenergi väntas öka drastiskt i Sverige under de kommande åren (Bränström, 2014). Ännu är den förnyelsebara energin en relativt liten del av energiproduktionen och för att nå EU:s direktiv måste energin från förnyelsebara källor öka med drygt 25 procent fram till år 2020 (Jordbruksverket, 2014). Studien fokuserar på solel i Sverige, framför allt i Stockholm bland flerbostadshus med upplåtelseformerna hyresrätt och bostadsrätt. En fallstudie har gjorts för ett flerbostadshus som projekteras av Einar Mattsson Projekt AB på Kungliga Tekniska högskolans Campus i Stockholmsområdet. Potentiell produktion av solel har beräknats i samarbete med Apollon Energy Consulting AB där solpaneler liggandes på taket har jämförts med att vinkla solpanelerna på ställningar monterade på taket. Nettonuvärdet för investeringen har beräknats till 15 000 SEK då solcellerna monterats direkt på taket och till 10 000 SEK då solcellerna monterats på ställningar på taket. Vid beräkning av lönsamheten har en livslängd på 25 år och en kalkylränta på 5 procent antagits. Återbetalningstiden för båda fallen har uppskattats till cirka 13 år. Parametrar som påverkar nettonuvärdet är rådande elpriser, avskrivningstid, producerad mängd energi, investeringskostnader, bestämd kalkylränta och det statliga solcellsbidraget från länsstyrelsen. Studien visar att incitamenten till att investera i solceller är olika beroende på upplåtelseform och om investeringen sker vid nyproduktion eller vid ombyggnation av flerbostadshus. Bostadsrättsföreningar med god ekonomi har de starkaste incitamenten till att implementera solceller eftersom det bidrar till sänkta driftkostnader för fastigheten vilket på sikt kan innebära sänkta månadsavgifter, en ökning av lägenheternas försäljningsvärde samtidigt som de har kontroll över sina ekonomiska förutsättningar. Det långsiktiga ägandet medför att bostadsrättsföreningar inte bara betalar för investeringen utan också tar del av de besparingar som görs. Vid implementering av solceller vid ombyggnation av hyresrätter står fastighetsägaren för investeringen och det är också denne som tar del av de sänkta driftkostnaderna. Implementering av solceller ligger inte till grund för hyreshöjning för de boende. Vad gäller nyproducerade flerbostadshus kan solceller projekteras redan under projekteringsfasen vilket kan medföra lägre installationskostnader och en mer estetiskt tilltalande byggnad. Byggherren står till en början för investeringskostnaden medan fastighetsägaren tar del av besparingar i form av sänkta driftkostnader. Byggherren förväntar sig dock i stor utsträckning att få tillbaka investeringen då fastighetsägaren förvärvar byggnaden. / Undoubtedly, more focus is given to renewable energy sources in recent times. Researchers and practitioners unite in expectations of a growth in solar energy installed capacity in Sweden during the coming years. Nonetheless, sustainable energy sources merely represent acomparatively small portion of total Swedish energy production. As such, a significant increase of this proportion is crucial in order to meet the UN directive goals. This study focuses on photovoltaic energy utilization on Swedish multifamily buildings with tenancy right and tenant ownership in Stockholm.   A case study is done on a multifamily building at the campus of Royal Institute of Technology. Potential amount of energy produced from 70 photovoltaic panels has been calculated in two different states; one with solar panels mounted on rooftop standings in an optimum angle towards the sun, and the other with solar panels mounted directly on the rooftop facing up. Assuming a life time of 25 years and a 5 percent cost of capital the net present value for the investment has been calculated to 15 000 SEK with solar panels mounted directly on the rooftop and 10 000 SEK with panels mounted on standings. Payback time for both cases has been calculated to approximately 13 years.   This study shows that there are different incentives for an investment in a photovoltaic solar farm depending on the tenure of the apartment building and whether it is a new- or reconstruction. Housing cooperatives with stable economy has the strongest incentives for implementing solar energy since it will contribute to lower operating cost of the building, which can result in lower monthly fees for households and increase the market value of the apartments. Due to the long-term ownership the housing cooperatives are paying for the investment and the households also take part of the savings.   The property owner of an multifamily building with tenancy right invests in the solar farm and takes part of the savings due to lower operating costs during a rebuilding. The households are not affected economically. If the solar cells are implemented during a new construction there is possible to decrease the cost of installation and it is easier to construct an appealing building. Initially the construction company invests in the solar farm and the owner of the property is obtaining lower operating costs. However, the construction company expects to earn their investment back in connection with the sale of the apartment building.

No description available.

The Scenic Rim is a significant agricultural region an hour west of Australia’s third largest city, Brisbane, and also the coastal beaches of the Gold Coast. This region has been driven by agriculture for its entire history. However, Brisbane and the Gold Coast region are rapidly expanding and as a result, there is expected to be a massive urban overflow into the Scenic Rim region, resulting in the region’s population more than doubling in less than 20 years. While this shift presents many opportunities for the region, it is also accompanied by many challenges. The Scenic Rim Community Plan 2011-2026 states that the citizens of the Scenic Rim intend to promote sustainable development, create jobs with locally run businesses, and establish a strong infrastructure that compliments their other goals (Scenic Rim Community Plan, 2011). The infrastructure of the region will be under a large amount of pressure with the sudden influx of people migrating there. Complex adaptive systems theory (CAS) combined with transition theory is used here as a framework to show that the system is dependent on the interaction of agents and the feedback from those interactions as well as feedback from the entire system and external environment. CAS also states that a system is susceptible to changes in the environment, whether that be new rules and policies, or external disturbances. CAS is a good representation of a region as a region is comprised of a complex array of agents interacting with each other towards regional outcomes. System rules from a regional perspective refer to laws and policies which can have long reaching effects on a region if changed. Referring to a region in terms of CAS means region must be resilient and adapt to external system disturbances such as this mass migration or natural disasters. This research uses CAS and transition theory to show that in order to be adaptive as well as move the region towards the desired state of sustainability, the agents within the system must interact under new system rules which provide an environment that promotes and enables this transition. The key is to determine those rules or policy changes. A literature review showed that the main challenges faced by existing sustainable developments around the world were transportation, local employment, and sustainable housing, whether they were eco-homes, eco-villages, or eco-cities. The challenges found in the literature were combined with the hybrid CAS/transition theory framework in order to create a general template for addressing regional sustainability. The template provided a process which involved determining region specific sustainability projects, defining the agents responsible for those projects, and then discovering the system rule or policy changes required to push the agents to implement those projects. The implementation of these projects becomes the policy scenario within the scenario planning phase of this project. Utilizing this template with the general lessons learned from the literature combined with a significant amount of collaboration with the main stakeholder in the project, the Scenic Rim Regional Council, several potential sustainability projects were brainstormed in order to create a policy scenario. While these three projects alone were not expected to transition an entire region towards sustainability, the research focused on defining a process and template which could be scaled up in future projects to eventually result in a transition to a new desired state of regional sustainability. Three of the brainstormed potential projects were chosen to be analyzed in further detail in this project included repairing the old train line out of the Scenic Rim and creating a transit hub in the largest town Beaudesert, creating a co-working space close to the transit hub, and creating minimum requirements for new homes to have photovoltaics as well as solar hot water installed on their roofs. These three projects were chosen because together they address local employment, transportation, and housing in some capacity. Together these solutions formed the policy scenario within this research. In order to analyze the potential impact of these three solutions, an approximate energy model of the Scenic Rim Region was created. In this model, the solutions were modeled in a policy scenario and then regional performance up until 2040 was simulated and compared against a "business as usual" scenario in which it was assumed no changes were made in the future and projected performance was based solely on historical trends. The results of this analysis demonstrated that the policy scenario was able to drastically reduce the electricity demand of the housing sector in the Scenic Rim as well as drastically reducing the oil demand in the region. An approximate economic analysis was done of the policy scenario. The QLD PV feed in tariff and decreased electricity bills from the SHW system would more than offset the increase to the homes mortgage caused by the PV and SHW systems. The gas savings from only driving into the city once per week by using the co-working space more than offset the rental cost. The restored rail line would have a high initial investment, but the shared cost with Logan City combined with increased use results in the rail line paying for itself by 2029. This process and the hybrid CAS/transition theory framework proved to be quite effective and have the potential to be scaled up significantly to fully transition a region towards a sustainable future.

It is often considered that building performance in an operational phase is not as good as its designed performance. In fact, approximately 40% of the world’s total primary energy consumption is accounted existing buildings. Therefore, it would be of a great importance to analyze and optimize the existing buildings performance by taking total energy consumption and comfort situation into consideration. This is possible through measuring and analyzing the current building performance. Hammarby Sjöstad is a high profile example of sustainable city development which has been chosen as a case study in this research project because most of the operational buildings located there have not reached their projected efficiency during the design phase. Therefore, the main objective of this research study is to investigate this problem and formulate cost-effective, high performance solutions in order to increase the overall efficiency of the buildings in Hammarby area. In this study a “Case Study” methodology has been performed with literature studies, in-depth interviews, seminars and gathering of quantitative data, concerning the operational goals of the environmental program of Hammarby Sjöstad. To gather the required data, meetings with different organizations were scheduled. More than 15 important parameters were gathered for more than 100 buildings in Hammarby Sjöstad. Going through all the data, some relations were discovered which led to interesting yet simple solutions for the low energy efficiency of the buildings in the area. Patterns were recognized however they had to be evaluated and their accuracy had to be tested. Moreover, to further evaluate the performance of the buildings, Energy audits were done with the help of an energy expert. The aforementioned buildings were visited and their performance was checked in detail to further prove the pattern results. Different parameters were considered during the visits including the architecture, technical installations and maintenance. Meanwhile, by taking advantage of the DesignBuilder software, a number of simulations were performed in order to further examine the previous findings. Finally, some practical recommendations and also conclusions are presented.

Sammanfattning Denna studie har gått ut på att undersöka hur köldbärar　ödet påverkar värmepumpens och systemets värmefaktor samt föreslå hur flödet kan optimeras. En kopplingsprincip som tillåter att flödet genom värmepumpens förångare är lägre än flödet genom borrhålen har utvärderats. Köldbärarflödet fanns ha en avgörande betydelse för värmepumpens värmefaktor och vid de utförda experimenten ökade värmefaktorn näst intill linjärt med 　flödet. Tidigare forskning visar samma sak men att kurvan för värmefaktorn planar ut vid ytterligare höjning av köldbärarflödet. Beräknas istället systemets värmefaktor, där effekt för cirkulationspumpar räknas med, så existerar en punkt där en ytterligare höjning av köldbärarflödet ger en försämring av värmefaktorn på grund av ökad pumpeffekt. Inga resultat i studien tyder på att det skulle finnas en nytta av att ha lägre flöde genom förångaren än genom borrhålen. Istället ökade systemets värmefaktor vid sänkning av borrhålsflödena eftersom pumpeffekten kraftigt reducerades. Frågeställningen kommer att fortsätta utredas med en utförlig experimentserie. / Abstract The aim of this study has been to investigate the impact of the secondary fluid flow(the brine) on the coeffcient of performance for both the heat pump unit and the entire system. A by-pass on the evaporator side that enables the flow through the evaporator to be lower than the flow through the boreholes has been evaluated. Increasing the secondary fluid flow through the evaporator was found to increase the heat pump units coeffcient of performance and the relation was found to be almost linear. Previous research has shown the same result but the rate of increase in the coeffcient of performance is decreasing with higher fluid flow. If the systems coeffcient of performance is calculated instead, which means taking power for the brine pump into account, a maximum point exists from where a further increasing of the brine flow would decrease the systems coeffcient of performance because of increased pumping power. No results in this study shows any benefit of running the system with a lower flow through the evaporator than through the boreholes. Instead the systems coefficient of performance was found to increase with a lower borehole flow because of reduced pumping power. This study will be followed by an extensive series of experiments.

Projektet har undersökt potentialen av nya solfångarinstallationer i Stockholmsområdet. Behoven, platsen och byggnaden som har använts för beräkningarna har varit baserade på Sollentuna sjukhus. Målet var att undersöka vilken typ av solfångarsystem som är mest ekonomiskt och energimässigt lönsam. Dessutom har flödesscheman för solfångarsystemen skapats och inkluderas med en grundläggande styrning. Värmen från en solfångarinstallation kan användas inom flera olika områden. Den kan exempelvis värma upp tappvarmvattnet i en byggnad, skapa komfortkyla eller ingå i ett elkraftverk. Beroende av ändamålet kan olika sorters solfångare användas. För Sverige och Sollentuna sjukhus behov står detta val mellan plana solfångare och vakuumrör. Utöver panelerna består installationerna av ett rörsystem, med ingående komponenter, för transport av värmebäraren samt ett värmelager. I detta projekt har fyra eget designade system jämförts mot varandra: • Ett system som förvärmer varmvattnet, den vanligaste sortens system i Sverige. • Ett system som både förvärmer varmvattnet och värmebäraren i radiatorsystemet med hjälp av planasolfångare. • Ett system som både förvärmer varmvattnet och värmebäraren i radiatorsystemet med hjälp av vakuumrör. • Ett system avsedd för att producera kyla och som även förvärmer varmvattnet. För att beräkna prestandan för respektive systemlösning har ett flertal uträkningar och uppskattningar gjorts och därför har både Excel och simuleringsprogrammet TRNSYS 17 använts. I Excel har ett individuellt program skapats som användes för tidiga och dimensionerande beräkningar. TRNSYS 17 har sedan tillämpas för de slutgiltiga energisimuleringarna. Utöver energiberäkningarna utförda i TRNSYS 17 har Excel även använts för mindre beräkningar, exempelvis för tryckförluster i rören och ekonomin. För flödesscheman användes AutoCAD 2012. Resultatet visade att den bästa lösningen både ekonomiskt och energimässigt är den som använder vakuumrör för att förvärma varmvattnet och värmebäraren i radiatorsystemet. Detta på grund av den ökade tiden som systemet kan användas likväl som den höga användningsgraden. Dock var ingen av lösningarna ekonomiskt gynnsamma, vilket kan ändras med andra komponenter och energipriser.

The Electricidade de Moçambique, E.P. (EDM) is the power utility in Mozambique, responsible to generate, transport and distribute electricity all over the country. The company has three gas turbines installed at Maputo Power Plant. All units burn diesel oil and are used only for back up. Currently only the unit #2 is available for operation. The main constraint that EDM faces is the high operation costs due to diesel price. Hence the company is considering converting units #2 and #3 to burn natural gas, resource available locally. The country is currently exporting natural gas to the neighbouring Republic of South Africa. This MSc thesis project calculates the power output of all gas turbines when burning natural gas and optimizes the power plant capacity by proposing modifications of the current power turbine cycles to allow sustainable operation

No description available.

Natural gas consists of carbon hydrates and is utilized in the residential, commercial industrial and transportation sector and for power generation. Due to the fact that natural gas emits 23 % and 44 % less carbon dioxide than oil and coal respectively when burned, it becomes a more attractive fuel from an environmental perspective. Traditionally, natural gas is transported via pipelines. However, due to the fact that the geographical areas where natural gas is used often are a long distance away from the gas fields where natural gas is extracted, the gas needs to be transported long distances. For this reason, natural gas is cooled to a temperature of -162 °C to become liquid, or liquefied natural gas (LNG) in order to transport the gas in specially designed shipping vessels or trucks. LNG has a volume that is 1/600 of natural gas in gaseous state. For numerous reasons, most LNG is traded on long term contracts and priced on a formula linked to the oil price. One main reason being that infrastructure investments required for delivering and receiving LNG are capital intensive, thus need to acquire financing by securing cash flow through reliable long-term contracts. At the moment, Japan is the largest buyer of LNG in the world and the index for Japan and Korea LNG import prices, more known as the Japan/Korea marker, serves as the most common LNG-based index for spot trade. Financial derivatives are a common instrument in most commodity markets that is utilized for hedging price risks and speculating on price developments for the underlying commodity. Financial derivatives need to be traded on a market with enough trading volume in order to become sufficiently liquid to satisfy the needs of stakeholders trading the derivatives. However, the contracts currently priced on an LNG index only make up a fraction of the global LNG market and therefore the financial derivatives referencing to the price are traded in very small volumes and cannot be considered liquid. This study is conducted in order to look at the development of financial derivatives in the LNG market. The aim of the study is to identify driving factors for the liquidity of LNG financial derivatives. A qualitative approach is used in order to gather data that is used to map the LNG market, its actors and different price mechanisms. An analysis of the data is carried out in order to create new theories about the research question. The results of the study identify ten driving factors that affect the liquidity of LNG financial derivatives: 1. Supply of LNG, 2. Demand of LNG, 3. Leaving oil indexation, 4. Fragmentation among suppliers, 5. Number of players in physical market, 6. LNG index reliability, 7. Willingness to price on LNG index, 8. Players trading financially, 9. Clearing houses, and 10. Contract length. From further analysis, it is concluded that the current immature and illiquid market situation for LNG financial derivatives is mainly derived from reluctance to use LNG indices when pricing physically traded volumes. Factors that drive the future pricing of the contracts are a decrease in length of the physical contracts and fragmentation among suppliers of LNG.