David Harries

Concentrating Solar Thermal Heat Storage Using Metal Hydrides

Increased reliance on solar energy conversion technologies will necessarily constitute a major plank of any forward global energy supply strategy. It is possible that solar photovoltaic (PV) technology and concentrating solar thermal (CST) power technology will play roughly equal, but complementary roles by 2050. The ability to increase reliance on CST power technology during this period, however, will be constrained by a number of factors: the large plant sizes dictated by economies of scale, the high associated transmission infrastructure investment cost, and the limitations of current thermal energy storage technologies. Thus, solar technologys main midterm role is seen to be as hybrid solar thermal power plant. The development of low-cost, high-temperature, high-energy density thermal energy storage systems is needed to enable CST plants to be dispatchable and accelerate the deployment of this technology. Thermochemical storage has the best potential to achieve these energy storage requirements and a brief overview of thermochemical energy storage options for CST plants points to high-temperature metal-hydride thermochemical heat energy storage systems. Hydrogen storage systems offer the highest energy storage capacity per volume and are therefore the most likely candidates for achieving the goal of fully dispatchable CST plants. A number of high-temperature metal-hydride thermochemical solar energy storage systems have been proposed and a small number of these systems are currently being investigated and developed. A key component of this work is matching the thermochemical metal-hydride system with a suitable “low-temperature” hydrogen storage material to produce systems that are self-regulating. A summary of the development status of these systems suggests that, despite the technical challenges associated with high-temperature thermochemical energy storage systems, their potential advantages are now seeing development occurring. Although in the early stages, their commercialisation could be fast tracked.

Hydro, tidal and wave energy in Australia

The three renewable energy technologies discussed in this paper are based on water, but differ markedly in terms of the size of the available potential resource, the maturity of the associated conversion technologies, the extent to which they have been exploited to date, and the current research effort being devoted to their future development. Hydro-electricity and tidal power are both very mature technologies. The exploitation of Australias relatively limited potential for hydro-electric development began over a century ago and the opportunities for further hydro-electric development are now very restricted. The countrys significant tidal power resources, on the other hand, have not been exploited for electricity generation to date, but continual assessment of the feasibility of tidal power projects has been undertaken over the past half century. Although Australia has large ocean wave energy resources, ocean wave energy conversion technology is not yet fully commercial and no commercial wave generation plants are operating in Australia. A small number of wave energy conversion devices, however, are at the pilot testing stage.

Geothermal energy in Australia

Although Australia is not usually associated with geothermal energy, it possesses significant amounts of both conventional (wet) geothermal and hot dry rock (HDR) geothermal resources. The countrys conventional geothermal resources are extensive, but are low temperature and are located in areas of low population density with the result that they are not used extensively for either electricity generation or for direct heating. Australias HDR resources, on the other hand, represent a world-class resource but have not been used to date because the technology for converting HDR resources into electricity is not yet fully commercial. The effort being directed towards exploring economically useful HDR resources and in the development of technology to convert this energy resource into electricity could make HDR resources an important part of Australias energy mix in the near future, but there are major barriers.

Success and Sustainability Criteria and Issues for SHS Programmes

Solar home systems (SHSs) have been increasingly seen to be and promoted by many as the best solution for providing access to electricity in remote and rural areas of developing countries where supplying electricity from the grid is not a practical option. To date, many SHS programmes had been implemented in developing countries. The evidence that exists suggests that many of these SHS programmes have indeed met with limited success. Improving the effectiveness of these programmes will be important for obtaining increased political and bureaucratic support for investment in future SHS programmes. Finding ways for these programmes to achieve greater success will require a better understanding of the factors that contribute to the success of some programmes and those factors that contribute to a relative lack of success of others. This information will be needed to inform the development and implementation of future programmes. This chapter describes a model for evaluating programme success that uses a number of success criteria and indicators that can be used to measure programme success.

Acquiring knowledge and information on alternative energy from the world wide web

Uncertainty over future oil prices, concerns over and energy security and increasing agreement over an urgent need to reduce global greenhouse gas emissions to avoid unacceptable temperature increases and climate change have combined to generate strong interest in low emission energy supply options, including increased efficiency of energy use and renewable energy technologies. These energy options, variously labelled as clean energy, renewable energy, sustainable energy or alternative energy, need to be rapidly developed and deployed in order to reduce the current heavy reliance on fossil-fuels. The distribution of information and knowledge on these technologies is critical to this goal. The need to obtain such information will be more acute for developing countries such as Thailand as funding and support for scientific research and technological development in these countries is relatively limited and the ability to gather relevant information and knowledge via the World-Wide-Web will therefore be of particular importance in promoting know-how to local communities. This paper presents the outcomes of the first phase of a research project that aims to improve the extraction and visualization of alternative energy information from the Web. This paper reports a survey and study of 113 websites on alternative energy and examines the deployment of Web technologies by these websites. This will lead to the design and development of information extraction and visualization methodologies in the subsequent phases of the study.

Framework for Successful Implementation of SHS Programme

The solar electrification programme success is assessed on the basis of the degree to which they meet their objectives, and this in turn is determined by multiple factors. Careful consideration of the success factors during programme design and their incorporation into a programme will not guarantee that all of the programme’s objectives are fully achieved, but the omission of any of the factors would significantly put the programme’s sustainability at risk. These success factors and the roles of the various stakeholders can be combined to develop a sustainability road map for a SHS programme. The aim of this road map is to provide programme implementers, private sector players, policy makers and funding agencies with an implementation pathway that can be followed in designing, implementing and evaluating SHS projects for remote and rural communities using relevant information. It has a strong focus on project planning, management, implementation and evaluation and is not a technical teaching guide.

Solar Home Systems—A Description of the Technology and Its Applications

The concept behind the design of a renewable energy supply system is the technical, economic, social and ecological optimisation of the various components—the renewable energy generator, the energy storage unit, as well as the operating philosophy, which involves the energy management system, load shedding, dumping of generated energy and conventional generator backup. In this section, stand-alone photovoltaic systems for rural electrification are presented from a technical point of view with a focus on solar home systems. The knowledge on the components and the overall system enables the above design of solar home systems.

Choosing the Right Path

Some SHS programmes that had been or were being delivered in rural and remote areas in developing countries were more successful than others. A large number of SHS programs and other types of renewable energy programmes and projects implemented in developing countries over the past two decades had been relatively unsuccessful from even the perspectives of those implementing the projects. This raised two burning questions: why these programmes had been less successful than their implementers had hoped and how could they have been designed and implemented in ways that would have made them more successful. A better understanding of the causes behind the failures of limited success of many of these programmes and, conversely, the relative success of others is needed. Based on a comprehensive review of the literature we then went on to undertake our own SHS programme case study reviews and surveys, and thirdly interviewed SHS programme designers and implementers. These strategies were used to gather and to pull together sufficient data and information to be able to understand the full suite of relevant factors that can have an influence on the outcome of a SHS programme, and to understand what works and what does not work, and why. The result of this work is the comprehensive set of issues that need to be considered in each of the steps that are essential to the design and implementation of a successful SHS programme, which are described in detail in the previous chapter. This chapter explains that a road map is not a complete solution but a guideline to develop such projects. There are some complex issues that programme planners, designers and implementers are going to have to grapple with that a road map cannot be used to make those decisions or judgments, but can be used to help inform those decisions.

Overview of Financing Mechanisms for Solar Home Systems in Developing Countries

Solar Home Systems (SHSs) are used as the household’s source of electricity primarily by rural households in remote villages in areas in developing countries in which the national or regional electricity grid has not been built. Like all renewable energy conversion systems, initial capital cost of a solar home system represents a high proportion of the system’s total life-cycle cost. This makes the system unattractive for providing electricity access to rural areas by the national or regional electric utilities. Those living in such areas tend to be the poorest of the poor with very low incomes and without the ability to pay the upfront costs of a SHS. An important prerequisite for a rural PV electrification programme in developing countries is the mobilisation of the financial means required for the acquisition of the systems. Local banks and finance institutions tend to categorise SHSs as a high risk investment, and therefore, showing lack of interest in providing finance for SHSs means that other financial mechanisms are required. Different types of financing schemes available and used in different SHS programmes around the world are presented in this chapter.

Renewable Energy Policy and Practice in Western Australia

Renewable energy is commonly seen as an essential strategy for sustainability. Many governments, however, have sustainable energy or sustainability strategies that place little emphasis on renewable energy. One reason is that despite acceptance of the concept of sustainable development as a concept, the reality is that economic growth remains the dominant policy objective of most governments and sustainability and sustainable development are such ill‐defined concepts that lack of precise definition often confuses the debate. Climate change, however, is one issue for which the meaning over what is sustainable and what is unstainable has become clearer and the need to balance economic growth with reductions in greenhouse gas emissions has become urgent. The question of by when, by what means, by how much and by whom GHG emissions need to be reduced are now the critical questions. The question of the extent to which renewable energy is essential to the goal of reducing emissions therefore has become more pressing. Some governments continue to see renewable energy as an expensive and unnecessary option and that other, lower cost options for reducing greenhouse gas emissions from the energy sector exist. Western Australia makes an interesting case study as the State is experiencing rapid economic growth supported by rapidly increasing energy use and greenhouse gas emissions. Policies to date have focused on the fact that the state relies heavily on natural gas rather than coal and encourages the efficient use of energy. Western Australias energy situation and greenhouse gas emissions strategies are reviewed in order to assess the extent to which this greenhouse gas reduction policy that has to date placed a relatively low emphasis on renewable energy is likely to be successful.