Framework Convention on Climate Change

Inspired by the energy democracy movement, this conceptual review critically explores relationships between concentrated or distributed renewable energy and political power. Advocates assert that because the renewable energy transition is fundamentally a political struggle, efforts to shift from fossil fuels and decarbonize societies will not prove effective without confronting and destabilizing dominant systems of energy power. The objectives of this paper include: 1) theorizing and exploring the relationships between renewable energy and political power, 2) critically assessing tensions associated with an energy democracy agenda, and 3) drawing out the implications for democratizing renewable energy development in practice. Distributed energy-politics posits that distributed energy sources and technologies enable and organize distributed political power and vice versa. Efforts are underway to find ways to re-organize distributed energy flows into aggregated and concentrated stocks of energy and other forms of political power. More democratic renewable energy futures may benefit from strengthening democratic practices and outcomes, extending democratization of energy systems across all components, stages and end uses, and sharpening positions relative to dominant pressures of capitalism and market ideology, the ideology of unlimited growth, and the modernist/industrialist agenda. Renewable energy systems offer a possibility but not a certainty for more democratic energy futures.

Political power and renewable energy futures: A critical review

Is a 100% renewable European power system feasible by 2050?

A comprehensive review on solar cookers

The overuse of fossil fuels in real life applications has caused their rapid depletion and fast climate change due to global warming and thus access to eco-friendly energy resources has become essential to meet the growing demand of clean energy. With this view, solar energy has proven to be an effective alternative and clean source of energy for the sustainable development of the society worldwide. Solar energy is a cheap, abundant and everlasting source of renewable energy and thus it can be integrated with different systems deals with energy consumption to overcome the dependency of present society on conventional fuels. Such integration of solar energy has given an opportunity for several studies based on the energy and exergy approaches. The energy analysis is very crucial in the study of process effectiveness while the exergetic analysis is another important tool to investigate the realistic behaviour of process involving various energy losses and internal irreversibility. The main objective of this article is to bring out valuable recommendations for wide exploitation of solar energy systems for different applications, from a thermodynamics perspective. Therefore, the present article has summarized the previous findings on energy and exergy analyses of different solar energy systems (solar drying, solar air conditioning and refrigeration, solar water heating, solar cooking and solar power generation through solar photovoltaic and concentrated solar power techniques used for various heat and power generation applications).

Energy and exergy analyses of various typical solar energy applications: A comprehensive review

Hydropower is an important renewable energy resource worldwide. However, its development is accompanied with environmental and social drawbacks. Issues of degradation of the environment and climate change can negatively impact hydropower generation. A sustainable hydropower project is possible, but needs proper planning and careful system design to manage the challenges. Well-planned hydropower projects can contribute to supply sustainable energy. An up-to-date knowledge is necessary for energy planners, investors, and other stakeholders to make informed decisions concerning hydropower projects. This is basically a review paper. Apart from using expert knowledge, the authors have also consulted extensively from journals, conference papers, reports, and some documents to get secondary information on the subject. The paper has reviewed the world energy scenario and how hydropower fits in as the solution to the global sustainable energy challenge. Issues of hydropower resource availability, technology, environment and climate change have been also discussed. Hydropower is sensitive to the state of environment, and climate change. With global climate change, though globally the potential is stated to slightly increase, some countries will experience a decrease in potential with increased risks. Adaptation measures are required to sustainably generate hydropower. These are also discussed in the paper.

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Hydropower in the Context of Sustainable Energy Supply: A Review of Technologies and Challenges

The importance of renewable energy such as small hydropower for sustainable power generation in relation to its capacity to contribute towards alleviating acute shortage of rural electricity supply in the sub-Saharan African region has been discussed. A relatively comprehensive small hydropower technology review has been presented. Rural electricity supply scenario in the region has been presented and, in general, the region has very low electricity access levels coupled with various challenges. Small hydropower technology has been discussed as one of the promising decentralised power generation system for rural electricity supply in the region. Despite challenges in data acquisition, this paper has shown that the SSA has significant hydropower resources, but the level of installation is very low. Challenges hampering SHP technology development in the region have been identified and discussed, such as those concerning technology, climate change, finance, and policy. This is basically a paper where the authors consulted a wide range of literature including journals, conference proceedings, and reports as well as expert knowledge in the area. It is hoped that this paper contributes to the information base on SHP technology which is quite lacking in the region.

/pdf/potential-of-small-scale-hydropower-for-electricity-2fx8ozgr6w.pdf

Potential of Small-Scale Hydropower for Electricity Generation in Sub-Saharan Africa

Shortage of electricity supply and other forms of modern energy is serious in most of the developing countries, contributing to low economic and social development. The situation is worse in rural communities, which are often marginalised from grid-based electricity supply because of economic and technical reasons. Currently, development agencies involved in rural power supply in developing countries recommend microhydropower (MHP) as the most robust and reliable source of off-grid power generation. However, in scholarly articles, MHP technology is not popular compared to other renewable energy technologies. This may have contributed to its limited application in off-grid power supply in some countries. Availability of scholarly literature on MHP as the case with wind and solar energies can therefore help to scale-up the level of discourse on the technology among both technical and non-technical stakeholders. In this paper, the MHP technology has been reviewed in general and the turbines in particular. General description of the technology including challenges and factors for successful implementation of the technology has been given. It has been found that technological issues are among the major challenges and that the turbine is one of the critical technological components of the MHP project. The paper has reviewed common MHP turbines, focusing on their operating principles, merits and demerits with respect to MHP and suitable operating conditions. Factors to consider when selecting suitable turbine for the site and procedure for selecting the turbine have also been outlined in the paper. The paper has been written in a tutorial manner so that the discussions therein, though technical, are shared with stakeholders of different professional backgrounds. It is hoped that the paper provides additional knowledge on MHP technology and in particular on turbines that are used in MHP supply. This can lead to better practical implementation of the technology.

A technical discussion on microhydropower technology and its turbines

The most common type of energy used is firewood. In some Sub Saharan countries, up to 90% of total energy use is from firewood. The consumption of wood fuel is in some countries as high as twice the sustainable yield, something that has led to environ-mental degradation due to deforestation and scarci-ty of firewood. The use of fossil fuels such as kerosene and LPG for cooking is expensive. Solar energy is a non-consumptive and non-polluting fuel. It can help alleviate the problem of insecurity of cooking energy, which is the major domestic energy requirement. Several attempts have been made to introduce solar cookers in different coun-tries and have achieved variable successes. There are still critical issues yet to be resolved in order to make that technology acceptable for wider dissemi-nation. They include getting the most appropriate types of solar cookers for specific locations, opti-mum size/capacity, types of materials to be used, optimal design and affordable cost. In an attempt to resolve these issues, a comprehensive study involv-ing theoretical review, development work, experi-mental testing and evaluation of solar cookers was conducted for several years on six different types of solar cookers. The cookers are the ‘SunStove’ box cooker, wooden box cooker, panel cooker, reflector cooker with unpolished aluminium reflectors, reflec-tor cooker with polished aluminium reflectors and reflector cooker with glass mirror reflectors. This paper presents the results of the study. Results obtained indicate that many of the cookers could be used to cook food for households in areas with medium and high insolation, with appropriate selec-tion of the type and specification of the cookers. The specification should be based on the measured inso-lation data of the location indication of the direct and diffuse components. As a guiding tool, reflector cookers offer best comparative performance in areas with longest durations of clear sky (greatest direct beam), panel and collector cookers under moderate cloudy conditions and box cookers under very cloudy conditions.

Development and performance testing of solar cookers

According to the 2010 Malawi Demographic and Health Survey (MDHS), about 65% of households in Malawi do not have access to treated water. Distillation is one technique used for treating water. Many distillation methods are available but they are either energy intensive or contribute to environmental degradation due to their nature. However, solar energy can be used as an alternative source of energy for water distillation. There are many designs of solar distillation systems but the most-widely used one is the conventional still. Internal surfaces of the walls of the conventional solar still (CSS) are commonly painted black to avert condensation of water vapor on the walls. However, the CSS suffers from low production of distilled water and there is, therefore, a need to improve its performance. In this study, two conventional stills were designed with an identical geometry but the internal surfaces of their walls were painted white. These solar stills were tested outdoors under the same meteorological conditions at the Malawi Polytechnic (15° 42' S, 35°02' E). Distillate output was measured during experimentation. It was found that the average daily distillate outputs were 2.55 kgm-2 and 2.38 kgm-2 for the experimental still and CSS respectively. In addition, the efficiency of the experimental solar still was 6.8% more than that of the CSS. It can therefore be concluded that painting the internal surfaces of the walls of the still white improves the distillate output of the still.

http://repository.udsm.ac.tz:8080/xmlui/bitstream/handle/123456789/159/Improved%20Solar%20Still%20for%20Water%20Purification.pdf;sequence=1

C. Z. M. Kimambo

Papers

Hydropower in the Context of Sustainable Energy Supply: A Review of Technologies and Challenges

Potential of Small-Scale Hydropower for Electricity Generation in Sub-Saharan Africa

A technical discussion on microhydropower technology and its turbines

Development and performance testing of solar cookers

Improved Solar Still for Water Purification