Ocean Thermal Energy Conversion (OTEC) is a renewable energy technology that has to overcome several key challenges before achieving its ultimate goal of producing baseload power on a commercial scale. The economic challenge of deploying an OTEC plant remains the biggest barrier to implementation. Although small OTEC demonstration plants and recent advances in subsystem technologies have proven OTEC’s technical merits, the process still lacks the crucial operational data required to justify investments in large commercial OTEC plants on the order of 50-100 megawatts of net electrical power (MWe-net). A pre-commercial pilot plant on the order of 5-10 MWe-net is required for an OTEC market to evolve. In addition to the economic challenge,OTEC plants have potential for adverse environmental impacts from redistribution of nutrients and residual chemicals in the discharge plume. Although long-term operational records are not available for commercial sizeOTEC plants, synergistic operational data can be leveraged from the desalination industry to improve the potential for OTEC commercialization. Large capacity desalination plants primarily use membranes or thermal evaporator tubes to transform enormous amounts of seawater into freshwater. Thermal desalination plants in particular possess many of the same technical, economic, and environmental traits as a commercial scale OTEC plant. Substantial long-term economic data and environmental impact results are now widely available since commercial desalination began in the 1950s. Analysis of this data indicates that the evolution of the desalination industry could be akin to the potential future advancement of OTEC. Furthermore, certain scenarios exist where a combined OTEC-desalination plant provides a new opportunity for commercial plants. This paper seeks to utilize operational data from the desalination industry as a progressive approach towards OTEC commercialization.

Renovation of the existing buildings in Sweden represents a great potential to achieve the energy efficiency and carbon emission targets set by the European Union and the Swedish government. The Energy Performance Contracting (EPC) is regarded as an efficient way to manage and to outsource the risks of energy efficiency (EE) measures. The thesis aims to identify the theoretical framework of EPC in the Swedish scenario and, through a real case, develop a model that relates EE measures and its results considering the capital investment versus running costs of renovation projects. The work is based on the incorporation with the Morastrand AB. The research expects to assess EPC processes and measures as in Energy Service Companies (ESCO) and consequently help in the decision making and the management of the projects. The thesis is composed of two parts. The first part identifies the theoretical framework of energy contract models focusing on the EPC, while a case study with Morastrand AB is subsequently presented. It is suggested one approach for the preliminary comparison of different renovation measures in EE projects, corresponding to the first step of the planning phase of an EPC. General recommendations and sensitive factors were identified and can assist Morastrand AB to effectively implement EE projects in the future. For orienting investments, the Lifecycle Cost Analysis (LCCA) is a method to study solutions under economic aspects and further it can be extended to the complete Lifecycle Assessment of the upcoming projects. The theoretical framework of the EPC is composed by identifying the projects, performing the technical analysis, determinizing the potential in energy savings, deepening the analysis with auditions, tendering the project, designing and executing the project, commissioning, operating and supporting the systems with constant monitoring and maintenance. The biggest challenge for the EPC in Sweden is the relation between the ESCOs and their clients. The figure of the facilitator could improve the results and balance the knowledge gap between the parts. The actors of these projects are the ESCO, the client, the facilitator and the financing part. In Sweden, very frequently the client finances the operation. There are a few models of contracting, and the most popular are guaranteed savings and shared savings. The thesis performed the LCCA of three options for window replacement in a building at the end of its lifespan. The results show that the trends in prices and interest rates are sensitive factors. In this case, the projects with higher initial investments were more profitable. Those solutions can shield the company against energy prices escalates and contribute to the green policies.

Fossil fuels are the major sources of electrical power generation in the world. Among all fossil fuels, oil is considered as the most sought-after fuel. The burden on countries that provide subsidized electricity produced from oil-fired power plants is noteworthy. Kuwait is a notable example of these countries. Electricity in Kuwait is heavily consumed by residential air conditioning, which comprises 60% of the total electricity generated at peak times on a hot summer day. From this perspective, residential air conditioning in Kuwait was selected to undergo further investigation regarding low energy air conditioning choices. Three solutions to control the rapid growth of demand for electricity by residential air conditioning are examined. The first solution investigated assesses the orientation and grouping of houses in Kuwait in order to examine their effect on cooling load and electrical energy consumption for future houses. Four residential cases were developed; each case comprises six typical houses. The cases identified are: (1) single block facing east-west, (2) single block facing north-south, (3) double block facing east-west and (4) double block facing north-south. Cooling loads are calculated using the DesignBuilder building thermal simulation software. Case (2) is found to have the smallest cooling load, and case (1) the largest. The estimated savings from applying case (2) compared to the average of the four cases for the future houses planned to be built by the government by the year 2016 (i.e. approximately 20,000 houses) are found to be approximately .US 33 million of power system capital costs, 15 GWh per year of electrical energy consumption and 11 kilotons per year of CO2 emissions. In the second solution, a lifecycle cost analysis is performed to evaluate the economic feasibilities of electricity driven chilled water system compared to predominant air conditioning system in Kuwaiti houses which is Packaged- Direct Expansion. The study considers the total cash paid by the consumer and the total cash paid by the government, since electricity is subsidized in Kuwait. The study finds that the chilled water system is not cost-effective for consumers due to high installation cost. However, a chilled water system would be cost-effective for the government because it consumes 40%less electrical energy than Packaged-DX. So, the study suggests subsidising the installation of chilled water systems so that the installation cost to the consumer is the same as for Packaged-DX systems. In the third solution, the study examines the viability of a single-effect LiBr absorption chiller driven by steam extracted from the steam turbine in the configuration of a combined cycle power plant (CCPP). The analysis shows that CCPP with absorption chiller yields less net electrical power available to utility grid compared to similar CCPP giving electricity to the grid and to Direct-Expansion air conditioning systems for the same cooling requirements. The reasons for that are the reduction in steam turbine power output resulted from steam extraction, and the amount of electrical energy required to operate the configuration of CCPP with absorption chiller.

Purpose. In Sweden, private commuting accounts for two third of total transportation emissions and 21% of the country’s total. To become net-zero by 2045, Sweden plans to have 2 million electric cars on the roads by 2030. Whereas with current pace, there will be 1 million electric cars by the end of the decade. Cars registered before 2016 (referred to as old cars in the study) make up nearly half of the Swedish car fleet. Thus, replacing the old emission intensive cars with the modern lower or zero emission cars will catalyze the decarbonization of Swedish transport sector. Therefore, the purpose of this study is to probe if it is economical to keep using an old car in the future or to replace it with a new one. Methods. This study first compares the next 13-year Total Cost of Ownership (TCO) of old V70 (having current milage 200,000 km) with that of new replacement cars. The (selected) replacement are the most registered modern-day cars in Sweden by fuel type having same size as that of V70: V60 (ICE), V60 (PHEV) and Tesla Model 3 (BEV). Moreover, using TCO framework, the study also estimates if the replacement is more economical now or sometime in the future with either new replacement cars or their (4-year) used models. Results. The results show that for next 13-years in Sweden, it is more economical to replace the old V70 with any of the replacement cars. However, Tesla Model 3 is the cheapest option among the new cars and V60 (PHEV) among the used cars. Overall, it is more economical to replace with a used car. In addition, the replacement is most economical if done immediately (in 2022) and gets more expensive by each year of delay- because the owner will have to incur relatively higher V70 costs (vis-à-vis the replacement cars) for an additional year. Sensitivity analysis shows that with higher current salvage value, a V70 gets more expensive to own in next 13 years (due to higher depreciation) whereas the replacement becomes cheaper (utilizing higher salvage value to buy the replacement car). Discussion. The study can be expanded to suggest economical and emission efficient replacement options for other old cars to accelerate the decarbonization of Swedish private transport sector. Furthermore, this study was done in collaboration with Mekonomen Group to see the financial worth of old ICE car replacement by its customers. The study results reinforce the group’s diversification strategy from ICE cars-oriented business model to BEVs as the top focus. Finally, this study is based on the assumption that the total number of cars in Sweden will not increase in future- the old gets replaced by the new. Therefore, from a holistic perspective, the study discusses that a sustainable transportation model should move away from private ownership towards shared mobility to avoid the rebound effects of technological efficiency that increase the overall resource consumption.

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As the COVID-19 pandemic became widespread around the world, the need to be able to work from home became clear to help reduce the spread of the virus, while at the same time showing that working from home could be successful in the future. While working from home can be positive, it also has drawback as reduce social interactions, hard to set working boundaries and more. This paper examines the viability to introduce a decentralized office space trough environmental sustainability, economic sustainability and social sustainability for a reference apartment building and an energy renovated one compared to a centralized office space. This study shows that working from a decentralized office space will reduce emissions with better utilization of the apartment building, saving the companies money and having a reasonable payback period for investors, while giving employees better personaleconomic and more free time without compromising on the social sustainability from not meeting people and having a hard time to different on working hours and non-working hours.