<p>Wave power is renewable energy which is environmentally friendly. Unlike most of renewable energy resources, wave energy can produce power all the year. The wave energy is stored in the ocean worldwide and highly concentrated near the ocean surface. It can be captured by wave power devices. Wave power is considered as a competitive energy resource in future.</p><p> <strong></strong></p><p>Waves are generated by wind blows across the surface of sea. Wave energy is one kind of mechanical energy which will be used for electricity generation. Wave power can’t be used directly to generate electricity; at first the wave energy is converted into the other form of useful mechanical energy and then converted into electricity. Wave power has a high potential to be captured and used for generating electricity in future as the technology develops further.</p><p> </p><p>Wave energy has been used since 1890s. There is a lot of energy stored in waves. 94% energy of the ocean stored in the wave, and the other 6% is tidal energy.  Only small a part of the wave power is used for commercial electricity generation today.</p><p> </p><p>The China is a developing country with a very large population which annually consume about 3073TWh electricity of which 496TWh is from renewable energy.  The wave power was less than 1GWh in 2007 (reference from International Energy Agency). The World Energy Council has measured the total useful power of the ocean wave energy to be more than 2TW in the world and corresponding to 6000TWh per year. There is about 70GW useful wave power resources in China, equivalent to an annual useful wave power resource of 200TWh.</p><p> </p><p>The lowest capital cost for the wave power system is today around 0.1Euro/kWh. China will in the future focus on the development electricity generation by wave power. There will be hundreds of new wave power plant built in China during the next twenty years, and the total installed capacity will be larger than 1GW at 2030, which delivers 3TWh annually. This corresponds to less than 1 percent of the total use of electricity in China.</p><p> </p><p>This thesis focuses on the functionality, efficiency and economic pay-off of existing ocean wave power systems, as well as how easy the ocean wave power can produce electricity. Firstly it discusses the physical concepts of wave power, and then focus on the existing wave power systems around the world. It is concluded from the Chinese sea characteristics and the designed conditions of different wave power systems, that the Pelamis and Oyster wave power converters are the best suitable systems for China.</p>

<p>This thesis investigates social impacts of charcoal use in households in the Tanzanian town Babati. In Tanzania a majority of the population use charcoal and firewood as their main energy source. A part from the environmental problems connected to charcoal use; there are also considerable social impacts on women’s daily lives. Cooking and collection of wood fuel are time-consuming and restricts the possibilities for women to work and study. The thesis includes an investigation on how the Tanzanian government tackles problems connected to charcoal use, social as well as environmental. The result shows that the Tanzanian government is working with charcoal related problems to some extent but as previous studies shows there are still more that can be done. The main efforts made concentrate on information campaigns and promotion of more energy efficient equipments. One important problem is however that wood fuel is the cheapest available energy source and hence the incentives to start using other, more sustainable, energy sources are very small. The thesis also investigates possibilities for Babati households to substitute charcoal use with renewable energy sources available in the town. The result shows that the possibilities to use renewable energy currently are very limited and mainly affordable to richer households.</p>

Microgrid is a relatively new concept which has gained significant attention recently due to the increasing penetration of distributed energy sources. It brings many benefits to the traditional distribution system. Couples of microgrid testbeds in the forms of either hardware facilities or software simulation systems have been developed to study microgrid issues in many institutes throughout the world. In the work presented in this thesis, a microgrid system model in PSCAD/EMTDC was developed. The proposed microgrid system includes fundamental power system component models, two renewable energy source models (wind and solar) and one energy storage source model. Different case studies were conducted. The results from the simulation case studies showed that the proposed microgrid system in PSCAD had satisfactory performance under different scenarios with renewable energy sources. The proposed microgrid system model can be used for further research on microgrid issues.

This thesis investigates social impacts of charcoal use in households in the Tanzanian town Babati. In Tanzania a majority of the population use charcoal and firewood as their main energy source. A part from the environmental problems connected to charcoal use; there are also considerable social impacts on women’s daily lives. Cooking and collection of wood fuel are time-consuming and restricts the possibilities for women to work and study. The thesis includes an investigation on how the Tanzanian government tackles problems connected to charcoal use, social as well as environmental. The result shows that the Tanzanian government is working with charcoal related problems to some extent but as previous studies shows there are still more that can be done. The main efforts made concentrate on information campaigns and promotion of more energy efficient equipments. One important problem is however that wood fuel is the cheapest available energy source and hence the incentives to start using other, more sustainable, energy sources are very small. The thesis also investigates possibilities for Babati households to substitute charcoal use with renewable energy sources available in the town. The result shows that the possibilities to use renewable energy currently are very limited and mainly affordable to richer households.

This thesis research aims to develop an improved, efficient, low-capacity heat engine, running on an Organic Rankine Cycle (ORC) to generate power. The ORC is driven by low or moderate temperature heat sources, such as; renewable energy in the form of a hot gas derived from biomass/biogas/biofuel combustion streams, waste heat recovery, process heat recovery, etc. The ORC is more suitable and flexible than a conventional steam Rankine cycle, especially when it is applied to low power range. In this research, an extended surface heat exchanger is used to boil the pressurised working fluid, R134a, using a hot air as heat source. The expander used is a scroll type, coupled to a generator, which is able to produce maximum 1.6 kW output. Experimental data of the heat engine are measured under different operating conditions and utilized in the analysis and comparisons. Power generation under various conditions is investigated in order to determine the optimum performance parameters for the heat engine. The isentropic efficiency of the expander is found to be over 40% and reaches 80% for the improved expansion conditions. For the boiler, it is determined that the overall heat transfer coefficient multiplied with the heat transfer area is around 150 W/K. The energy efficiency of the experimental ORC is around 3% for hot air as the low temperature heat source at about 105oC where exergy efficiency reaches 22%, respectively. / UOIT

Nowadays, renewable energy is in full growth. In particular, offshore wind farms will be at the centre of UK energetic strategy in the coming years. However, other types of marine renewable are still at an early development stage. That is the case for tidal energy. Many projects have been undertaken but there is no candidate for competitive commercial applications yet. Deltastream is one of these numerous pioneering projects. It consists of a set of three marine current turbines mounted on a triangular base put down onto the seabed. The device is not moored and no harm is done to the environment. However, that makes the structure more sensitive to water flows. And it is important to ensure that it will remain at its location and not being carried along with the tidal streams. Using CFD, the present study aims to evaluate the drag on the nacelles of the structure and come up with solutions to reduce it as much as possible.

The purpose of this paper, “Role of Nuclear Energy in Japan Post – Fukushima: Alternatives and their Impact onJapan’s GHG Emission Targets”, is to emphasize that Japan’s expected new energy policy must be in accordancewith its existing environmental targets with regards to GHG emissions. The main research question is how Japan cancontinue to meet its emissions targets in the aftermath of the Fukushima crisis, where public opinion—gaugedthrough newspaper articles—in Japan has now become outright anti-nuclear, and Japan has become compelled toadopt a new nuclear-free energy policy built around renewable energy. However, given the extremely low share ofrenewable energy in Japan’s existing energy mix, an extremely pro-nuclear government, an influential energy lobbyand an overall lack of suitable infrastructure; this goal does appear ambitious. The framework of analysis in thispaper will be of ‘sustainable development’, entailing an analysis of the three pillars of sustainability – environment,economy and social factors. In addition to these factors, security of supply will also be considered as a vital measureto determine the policy’s overall sustainability. The paper will show that while it is indeed possible for Japan tomeet its GHG emissions targets by replacing nuclear energy with renewable energy, Japan’s ability to deployrenewable energy at such a large scale remains inadequate. Through a comparison with the German experience inrenewable energy, any withdrawal from nuclear energy without properly propping up renewable energy will onlyresult in a greater shift towards primary fossil fuels – jeopardizing Japan’s emission targets, security of supply andincurring heavy import costs to its economy. The result of this analysis is to suggest measures such as an expansiveFeed-in tariff system, grid integration and stability and investment in R&amp;D as major components of a focused andlong term energy policy up till 2030, to promote renewable energy. This paper will also posit steps required toimprove the safety and efficiency of its nuclear reactors during the interim period when renewable energy grows inits share of Japan’s energy mix.

Green power, environment protection and emission reduction are key factors nowadays in the telecom industry. Balancing of these modes while reducing the capital and operational costs are of prime importance.  Cost efficient and reliable supply of electricity for mobile phone base stations must be ensured while expanding the mobile phone network. In this context, solar energy, using sophisticated photovoltaic cell technology, is considered to be playing very important role. Currently, companies such as ABI research, Flexenclosure AB, etc believe that the solar powered cellular base stations are capable of transforming the telecom industry into one of the greenest in the world. Hence, lot of research is in progress across the globe to use solar power in telecom industry. In this thesis work, the significance of solar power as renewable energy source for cellular base stations is reviewed. Moreover, simulation software called PVSYST4.37 is used not only to obtain an estimate of the cost of generation of solar power for cellular base stations but also to obtain the system parameters such as the number of modules, batteries and inverters needed for designing the solar powered cellular base stations. The simulations were carried out for the Grid-Connected and the Stand-Alone solar power systems by considering the cases of New Delhi, India and Stockholm, Sweden. The PVSYST4.37 simulation results shows that the power generation costs for the grid connected solar powered system is less compare to standalone solar powered system both in New Delhi, India as well as in Stockholm, Sweden.

Wave power is renewable energy which is environmentally friendly. Unlike most of renewable energy resources, wave energy can produce power all the year. The wave energy is stored in the ocean worldwide and highly concentrated near the ocean surface. It can be captured by wave power devices. Wave power is considered as a competitive energy resource in future.   Waves are generated by wind blows across the surface of sea. Wave energy is one kind of mechanical energy which will be used for electricity generation. Wave power can’t be used directly to generate electricity; at first the wave energy is converted into the other form of useful mechanical energy and then converted into electricity. Wave power has a high potential to be captured and used for generating electricity in future as the technology develops further.   Wave energy has been used since 1890s. There is a lot of energy stored in waves. 94% energy of the ocean stored in the wave, and the other 6% is tidal energy.  Only small a part of the wave power is used for commercial electricity generation today.   The China is a developing country with a very large population which annually consume about 3073TWh electricity of which 496TWh is from renewable energy.  The wave power was less than 1GWh in 2007 (reference from International Energy Agency). The World Energy Council has measured the total useful power of the ocean wave energy to be more than 2TW in the world and corresponding to 6000TWh per year. There is about 70GW useful wave power resources in China, equivalent to an annual useful wave power resource of 200TWh.   The lowest capital cost for the wave power system is today around 0.1Euro/kWh. China will in the future focus on the development electricity generation by wave power. There will be hundreds of new wave power plant built in China during the next twenty years, and the total installed capacity will be larger than 1GW at 2030, which delivers 3TWh annually. This corresponds to less than 1 percent of the total use of electricity in China.   This thesis focuses on the functionality, efficiency and economic pay-off of existing ocean wave power systems, as well as how easy the ocean wave power can produce electricity. Firstly it discusses the physical concepts of wave power, and then focus on the existing wave power systems around the world. It is concluded from the Chinese sea characteristics and the designed conditions of different wave power systems, that the Pelamis and Oyster wave power converters are the best suitable systems for China.

The use of ocean wave energy for electricity production has considerable potential, though it has proven to be difficult. A technology utilizing the heaving (up-and-down) motions of the waves was conceived at Uppsala University in the early 2000´s, and is being further developed for commercial use by Seabased Industry AB. The purpose of this master´s degree project was to increase the knowledge of the environmental performance of Seabased´s wave energy conversion concept and identifying possible areas of improvement. This was done by conducting a life cycle assessment (LCA) of a hypothetical prototype wave power plant. All flows of materials, energy, emissions and waste were calculated for all stages of a wave power plant´s life cycle. The potential environmental impact of these flows was then assessed, using the following impact categories: • Emission of greenhouse gases • Emission of ozone depleting gases • Emission of acidifying gases • Emission of gases that contribute to the forming of ground-level ozone • Emission of substances to water contributing to oxygen depletion (eutrophication) • Energy use (renewable and non-renewable) • Water use The methodology used was that prescribed by the ISO standard for Environmental Product Declarations (EPD) and further defined by the International EPD Programme.The potential environmental impact was calculated per kWh of wave power electricity delivered to the grid. The main result of the study is that the potential environmental impact of a wave power plant mainly stems from the manufacturing phase. In particular, the production of steel parts makes a large contribution to the overall results. Future wave power plant designs are expected to be considerably more material efficient, meaning that there are large possibilities to improve the environmental performance of this technology.