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منتدى البيئة و العلوم الزراعية... منتدى خاص بالعلوم الزراعية و التربية الحيوانية و البيطرة و علم البيئة و مخاطر التلوث و ما له علاقة بالطبيعة كالحياة البرية و المراعي... |
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لكل مهتم بالبيئة مقالات للطاقات البديلة بالإنجليزية
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2011-05-24, 18:51 | رقم المشاركة : 1 | ||||
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لكل مهتم بالبيئة مقالات للطاقات البديلة بالإنجليزية
السلام عليكم ورحمة الله تعالى وبركاته The dynamics of the drive towards business concentration is thought to be the dominant force in economic development, and, indeed, more and more industrial sectors are going down 84 CAPTIVITY OR LIBERATION this route, even those for which concentration is not imposed by the resource base, as it is in the case of the fossil fuel and mineral resource industry described in Chapter 1. Many economic analysts therefore assume that the introduction of solar resources will also be followed by a process of business concentration, and in consequence many also view local installations of solar generation plant as merely the precursor to a development whose end-point will be solar resource plantations in areas of high insolation such as North Africa. In actual fact, the scope for concentration with a solar resource base is limited. Indeed, the dominant force may well be the very difficulty of monopolizing solar resources, thus turning conventional and seemingly universally applicable experiences of economic processes on their head. Mathematically speaking, it follows that the *****alent to a 1000 MW power station would be – depending on their individual ratings – 2000–4000 wind turbines, 1 million solar panels, or 50 large or 5000 small biomass plants; in practical terms, the *****alent energy production would be achieved using a combination of these sources. The difference between the conventional energy industry with its four corporate pillars – the oil, coal, gas and uranium extraction and trading companies, the power station operators and the (in most cases identical) operators of the distribution grids, the power station construction industry and the investment banks that underwrite all the above – and renewable energy is that, in the latter case, only one sector is exposed to concentration and monopoly: the manufacture and construction of plant (ie, solar collectors, solar cells, wind turbines and biomass plants). If renewable energy sources ever come to dominate the market, then the rump of the industrial webs described above, the fossil fuel extraction and trading companies, will slowly dwindle away. There will be nothing to replace the niche currently occupied by companies that extract or supply fossil fuels if fossil fuels come to be displaced by solar heating, sunlight, wind, waves and water currents. As Franz Alt very neatly puts it, ‘the sun sends no bills’.10 The basic problem that fossil fuel companies have is that sunlight and wind cannot EXPLOITING SOLAR RESOURCES 85 be patented and sold under licence. Comprehensive use of renewable energy would take the wind from the sails of an economic globalization and industrial concentration process driven by the scarcity of fossil fuel reserves. This alone would spark a process of de-concentration, de-monopolization and the re-regionalization of economic structures. The two spiders in the fossil energy industry web – the operators of power stations and electricity and gas distribution grids – will also have no further role to play in a decentralized energy supply based on solar power. Large power stations need large companies to run them; small local plants have no such need. Once the transition to electricity supply from renewable sources can no longer be stopped, the power companies will naturally seek to gain control of these sources. In the case of PV, the highly decentralized nature of the plant makes this an essentially futile exercise. They will have more success with wind, especially with windfarms and offshore installations in coastal waters – how much success they would have depends on the extent to which the laws regulating the energy market favour this. But as generation plant for renewable energy is subject to natural limitations – the effective maximum capacity for individual wind turbines, for example, cannot be much more than 5 MW – power plant operation will no longer be purely the preserve of large companies. Provided that the market is freely accessible, many new types of enterprise are likely: local enterprise, on-site generation by companies, producer cooperatives and innumerable individual suppliers on a regional and local level. The politically and economically explosive potential of renewable energy is its universal availability, as this eliminates the dependency of both society and political institutions on power companies and reduces the influence that those companies can exert. Every large-scale power station decommissioned, every new local plant constructed and above all every improvement in power storage technology reduces the central role played by the national grid, to the point at which it becomes superfluous. The economies of scale, which have favoured concentrated business structures because of their ability to mass-produce cheap consumer goods and so squeeze out smaller producers, 86 CAPTIVITY OR LIBERATION do not apply to renewable energy. The rise of renewable energy disrupts two of the fossil fuel spiders’ strongest webs, and the third web, the dominant role played by the large investment banks in the energy industry, is at least weakened. In a decentralized market, all potential investors, not just banks, can be sources of finance; the large investment banks will be just one player among many. As mentioned, the market for renewable energy plant remains open to concentration and monopolization. It is possible that, following an initial boom, the global market for solar panels and accessories, solar collectors, wind turbines and biomass plants will come to be dominated by a very few firms. For the power station construction industry, this could even present a golden opportunity for diversification, provided they can make the leap from catering to a few large clients to serving many small ones. For PV and solar collectors, the customer base will be larger even than that of the car industry. That notwithstanding, manufacturers of solar generation plant will not be able to completely dominate the market. They will be dependent on a multi-billion-customer client base with a diverse demand structure for various panels and integrated systems. There will be scope for a broad spectrum of manufacturing and distribution firms, and an even broader palette of technical engineering and installation services. The representatives of the fossil energy industry have been written out of the script for the renewable energy story, or allotted at most a secondary role; the market for renewable energy will no longer have a niche for conventional sources – at least, not with turnover at high as it is at present. Conventional energy companies are bound to old fossil fuel structures by the sheer scale of their investments; their business models, based on large-scale industrial plant, will prove their own undoing in the transition to renewable energy. A solar resource base makes it impossible to retain or ever re-create the power structure that has hitherto prevailed in the energy sector. The short supply chains for renewable energy sources will end the pressure to globalize that comes from the fossil resource base. The dense interconnections between individual energy companies and between energy companies and other industries that result from fossil fuel supply chains will no longer be necessary. Shorter renewable energy supply chains also make it impossible to dominate entire economies. Renewable energy will liberate society from fossil fuel dependency and from the webs spun by the spiders of the fossil economy Solar power: technology without technocracy With very few exceptions, centralized power generation from solar sources would effectively negate the advantages accruing from a decentralized energy supply (the subject of Parts III and IV of this book). It would be daft to close down existing hydropower dams; large-scale solar thermal plants to supply tropical cities make sense. Equally, the resulting disconnection from the regional resource base makes biomass-fired power stations of over 100 MW nonsensical; nor are large tidal power plants along great stretches of coastline to be recommended, when wind power provides a simpler, less costly solution more in keeping with the natural landscape. In any case, even centralized solar power generation in sunnier parts of the world would inevitably need to be supplemented by local PV, wind, small-scale hydro and biomass plant. Yet the history of power generation and supply teaches us that although large-scale generation plant may be technically compatible with small-scale plant, combining the two produces structural conflict. Operators of large-scale plant need to run at full capacity to recoup their costs; the unpredictable output of small-scale producers is an irritant. There is little reason to assume that operators of large-scale solar power plant would behave any differently towards smaller suppliers than operators of nuclear and coal-fired plants. In the case of fossil fuels, the obsession with large-scale production and supply is a reflection of the underlying economic realities. In the case of solar power, the same obsession would be ill-considered, an expression of the industrial fantasies typical of the 20th century. Grand schemes following the pattern of concentrated generation and supply set by fossil fuel power generation have been and continue to be entertained in respect of renewable energy. They are the product of a paradigm that can conceive only of individual large-scale remedies for large-scale problems. 82 CAPTIVITY OR LIBERATION One example of this was the proposal of the Munich-based architect and author Herman Sörgel, first presented at a 1931 exhibition of architecture in Berlin, to construct a dam right across the Straits of Gibraltar to control the flow of water from the Atlantic into the more low-lying Mediterranean. The idea was to build a gigantic hydropower plant to supply Europe with electricity, while at the same time lowering the level of the Mediterranean to reclaim additional land from the sea along the Mediterranean coast and create a land bridge between Europe and North Africa. The Adriatic was to become dry land; Naples would have ceased to be a port. The project was much talked about; it fascinated Hitler as much as Mussolini.7 No thought was given to the incalculable consequences of reshaping the Mediterranean ecosystem on such a scale; the project was too tempting to geopolitical ambitions of making North Africa both a part of and, in conjunction with the greening of the Sahara, the breadbasket of Europe. Another, more contemporary example is the GENESIS project (Global Energy Network Equipped with Solar Cells and International Superconductor Grids) that some minds are toying with. The idea is to construct a global belt of linked solar power stations running along the equator to supply the entire world energy demand through a superconducting distribution grid. The supposed advantage would be an uninterrupted supply of solar electricity, because the difference between day and night and seasonal variation in output between hemispheres would cancel each other out.8 But the result would be a hypercentralized global energy supply, the global dominance of one generation technology with the longest supply chain imaginable and colossal infrastructural costs. It is a product of technological megalomania with absolutely no conception of the sociopolitics of energy supply. A third and similar example is NASA engineer Peter E Glaser’s concept of an orbiting ‘solar farm’, which also crops up in discussion from time to time. Electricity for all Earth’s inhabitants would be produced from PV platforms, orbiting the Earth, with a total surface area of many square kilometres, free of the limitations of diurnal and seasonal cycles. Generative efficiency would be very high because even incident EXPLOITING SOLAR RESOURCES 83 sunlight outside the angle of refraction (a product of the Earth’s curvature) could be exploited. The current produced would be beamed back to the ground in the form of microwaves with a ground footprint several kilometres in diameter. These would be picked up by a ground station almost 200 km2 in size, converted back into electricity and fed into the distribution grid.9 The same applies to this concept as to the GENESIS project: it may be technically feasible, but otherwise impractical, with no consideration of risk, economic viability or social consequences, and a failure to appreciate the real opportunities that solar power presents. Proposals that turn a local resource free of supply chain dependency into a hypercentralized generation and supply system, maximizing dependency, are the product of a technocratic approach that has no regard for social context; an approach which, even without such engineering mega-projects, has already led to the shaping of society to fit technology, rather than – finally – adapting technology to meet real needs. Even the idea of using Saharan solar power to produce hydrogen for export, although on a considerably less monstrous scale than GENESIS project or solar power satellites, fails to do justice to the economic, social and political dimensions of solar power. A resource that is universally available across the planet without recourse to extended supply chains need not and should not for any reason be first centralized under oligopolistic or monopolistic business structures before being redistributed to consumers at large. We must learn and understand that it is not necessary to take circuitous and technically complex routes when there are direct, simple solutions available. It is only possible to understand and harness the social and economic capacities of technology if we take an untechnocratic approach to it. The economic logic of the solar energy supply chain Fossil fuel and solar energy generation are intrinsically very different processes, and the opportunities they present for maximizing availability and efficiency – with respect to both resource consumption and financing strategies – are correspondingly diverse. Besides the differing environmental impact, the disparities between the supply chains demonstrate just how absurd it is to evaluate the economic potential of energy sources solely on the basis of the capital cost of the power generation plant required. It is because of such absurd reasoning that there has been such reluctance to exploit the potential of renewable resources. 76 CAPTIVITY OR LIBERATION Figure 2.1 compares the supply chains for fossil fuels and renewable energies, from which the following conclusions can be drawn: • The shorter the supply chain – ie, the smaller the number of distinct processing steps involved – the greater the scope for reducing the costs of energy generation. If improved solar technologies can be introduced on a large scale, they represent not just the least environmentally damaging strategy for meeting energy needs, they are also potentially the most productive and thus the most economic solution. For this to happen, it is insufficient merely to recognize the benefits of solar energy. Technologies and strategies must be developed to exploit its advantages to the full. Insufficient progress on this front is the reason why the greatest potential economic benefit of renewable resources has not yet been systematically exploited. As long as they remain embedded within the conventional framework for energy generation, providers and consumers of energy from renewable resources will continue to pay the costs of fossil fuel supply and distribution networks. The potentially decisive advantage that renewable resources have over conventional fossil fuels will continue to go unexploited. If the switch to renewable resources simply replaces elements of the established fossil fuel structure, this will introduce a systemic bias that will hamper the growth of the renewables sector, confining it to a peripheral role within the energy industry for some time to come. Effective use of renewable resources requires a radical rethink of the supply and distribution network – simply copying the established structure will not work. The construction and operation of the distribution grid, for example, typically constitutes more than half the costs of an electricity supply. It is in the elimination of precisely these factors that the greatest opportunity for productivity gains from renewable energy resources lies. It follows from this that productivity gains from renewable resources cannot be realized through the construction of multi-megawatt power plants with sprawling distribu- EXPLOITING SOLAR RESOURCES 77 tion networks. That is not to say that there is no place for solar thermal power plants. What is does imply is that such plants should not be used as the core of an inter-regional – or even international – distribution grid. The ideal use for a solar thermal power station would be to serve large towns and cities in its immediate vicinity – for example, Cairo’s power needs could be supplied by a plant located in the nearby desert. • On this basis, one criterion for evaluating the various technologies available for exploiting solar energy will be their potential for shortening or even completely eliminating the energy supply chain. On-site generation using PV cells, for example, may potentially be far more economic than large-scale generation plant. • One decisive advantage for renewable energy in the future lies in the ability to generate electricity at minimal technological and infrastructural cost. Because electricity is such a flexible tool, the demand for electricity will grow at an increasing rate, at the expense of other sources of energy. Within the current system, it is simpler to supply fuel for combustion when and where the energy is required. Converting the same fuel into electricity requires additional process steps, and thus is more laborious and technologically complex. With renewable resources, the opposite applies: electricity generation using PV and wind turbines is technologically the simpler route, whereas producing combustible fuel is more complex and long-winded. This reversal provides the template for the energy revolution to come زوروا مدونتنا لتستفيدوا اكثر
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2011-05-31, 17:08 | رقم المشاركة : 2 | |||
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السلام عليكم ورحمة الله وبركاته
حبذا لو قدمت الترجمة لتكون ذات فائدة أكثر ولان كذالك المواضيع هنا باللغة العربية فانتظر منك ترجمة الموضوع جزيت |
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2011-06-02, 09:40 | رقم المشاركة : 3 | |||
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بارك الله فيك أختي الكريمة وجاري الترجمة إن شاء الله |
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