Possibilities of renewable Energy projects in Afghanistan 1 . Introdution In the coming decades, we are likely to witness a profound technological transformation, This transformation will entail a switch un the global electricity system ,from primarily relying on fossil fuel to relying on renewable energy sources.the transformation to renewable energy is already gaining momentum,an the fast growth of renewables in the last year has led to falling costs and greater capacity in the design, manufacture and installation of renewable energy technologies. In 2011, nearly one quarter of all global electric generation capacity was renewable. The perception of renewable energy is changing and it is now increasingly seen as an important part of the global energy economy. Renewable energy technologies offer many country – level advantages including: greater energy security (locally produced), higher long-term pricing reliability, local job creation, balance of trade improvement, reduced environmental and climate change risks and cost effective off-grid deployment opportunities for rural electrification ,Several of these benefits still require more research to fully quantify their effects, in principle, these effects apply to all countries, industrialized as well as developing, but the pressure and desire to invest in renewable differ depending on a number of factors, such as a countries endowment of fossil and renewable resources, its economic strength ,attitudes toward climate and environmental protection ,and so on. There are several barriers to investment in renewable that have to be addressed. These include the cost structure of renewable compared to fossil fuel technologies, the intermittency of renewable energy supply, and levelised costs of electricity, which are often still higher for some renewable, Direct and hidden subsidies for fossil fuels are additional important considerations in assessing the viability of renewables. Government policies in different regions of the world have proven that private investment money is available for renewable energy deployment if the conditions are attractive. The most effective policy instruments to attract investment that have been used to date are feed-in tariffs, tax credits and quota system, Based on European and North American experience, the primary considerations for attracting investments are: 1. Transparency-govermental policies need to be easily understood. 2. Longevity-programs need to support long financial pay-back periods. 3.Certainty –programs need to be stable and predictable. 4. Cooperation – international coordination for macro-economic environment that is advantageous for global renewable growth. 5. Competition – competition among investors, as well as between developers and producers, keep program costs low. Renewable energy technologies, such as hydro, Solar, wind, geothermal and biomass energy, have a vast potential to be used for electricity and energy generation in Afghanistan and thus improve the livelihoods of ist people. Such technologies are cost-efficient, environmentally sustainable and based on indigenous resources. They can be applied even in the remotest village, enabling economic development in the whole country. Renewable energy (RE) is defined as that source of energy which is renewable from natural sources, such as the energy from the sun, wind, biomass, water and geothermal resources. Unlike, fossil fuels these sources of energy are abundant. The technology that converts a primary renewable source of energy or energy resource to the desired form of energy service is defined as Re technology (re,policy draft) Solar The country has excellent solar energy resources throughout its regions. Typically averaging over 5.5 kWh/m2/day annual global horizontal insolation and estimated at least 300 days for most of the country, with the south having the highest insolation. There exists a significant potential for solar heating (water and space) and standalone solar PV application for household lighting. Surveys indicate that kerosene is the most common fuel for lighting in non-electrified communities Over 100,000 solar home systems (SHSs) have been installed in various parts of the country by MRRD. However, MRRD discontinued the program due to quality related issues. Other donors and international Abstract This is solar air heating plate -plate collector. The collector uses high quality, long life parts in a high efficiency design. Overview This is my made design solar hot air collector. If you are looking for a super cheap collector this is not for you. But if you are looking for a lower cost, easy to work, long lasting collector that you will be proud of, this might be what you are looking for. Features of this collector: • This collector is a matrix absorber collector. • Vented aluminum vented soffit is used for the absorber matrix. • The glazing is carugated polycarbonate • . How it Works • Sun shines on the aluminum soffit absorber material, heating it up. • Cool room air enters the collector inlet, which is near the bottom and on the back of the collector. • A baffle placed just behind the glazing then deflects the incoming air to the sides and prevents the air from impinging directly on the glazing. • The air flows up and through the vented soffit absorber plate striping the heat off the soffit. • The air (now hot) flows up behind the soffit and out the outlet at the top back of the collector and into the room. • On typical 45-60c degree days, at midday the heater room is typically about 25 degrees, the adjacent rooms and the . fan is working with 5-10W solar panel great Width 0.5 m Length 2 m Air temperature 30-80°C ABSTRACT Solar space heating with warm air in typical air collectorsand rock bed storage systems involves constant air flow rates and varying temperature of supply to rooms and tostorage. This practice results in undesirable fluctuations in comfort levels in the living space, excessive storage size,useful but inaccessible heat in storage, and unnecessarily high energy consumption for air circulation and forauxiliary heat. These drawbacks can be avoided by use of a practical controller and variable speed fan to provideheated air from the collector at constant temperature and a continually varying rate.Collector manufacturer’s data, confiimed by seasonal tests on a solar air heating system in Solar House II atColorado State University, have been used in simulations at constant hot air supply temperatures of 40,50 and 6O”C,and at one typical constant flow rate of 49 kg/hr,m2 through a SOm2 collector and rock bed storage unit,providing approximately half the seasonal heating requirements of a residential building. Width 1 m Length 2 m HOT Water Collectors 1. Introduction Health and social communities in developing countries are institutes that daily use large quantities of hot water. When such communities are situated in areas that are hardly accessible, they mainly use wood fuel for water heating. Because firewood supply becomes an ever-growing problem, it is sensible to look for an alternative source of energy. Given the fact that solar radiation is present in abundance, it seems justified to manufacture self-made hot water systems. 1.1. Using solar energy The pluriform influence of solar radiation on life on earth can be used for several purposes. Proven applications for among other things generating electricity, water heating, cooking, and crop drying with solar energy exist. Small amounts of electricity can be generated with so-called P.V.-systems (Photo-voltaic). These systems can be reliable energy providers for remote areas (in which sometimes hospitals and clinics are situated). P.V.-systems are rather expensive. For maintenance and repair you need the manufacturers assistance. P.V.-systems can be used for: •Lighting; •Cooling boxes for storing medicines and blood plasma; Width 0.8 m Length 1.1 m water temperature 30-80°C SOLAR TUNNEL DRYER We are highly appreciated in the international market for our incredible assortment of Solar Tunnel Dryer. Our professionals make sure that quality-approved material and other components are utilized in the production process. These products are highly applauded by the customers due to their easy installation, outstanding performance and sturdy construction. The range we offer has a loading capacity of 230 kg/batch and is used for drying amla, chili, mango,grapes & other agro products. د هر ډول میوو او سبزیجاتو وچول Specifications: • Type of collector: Tunnel Type • Operating temperature: 45o to 65oC • Total area: 6feet x 60feet • Air heating area: 7.5 m2 • Cover material: U.V. Stabilized Plastic Sheet • Air flow arrangement: SPV operated 3 Nos DC fan with 1000 to 1200 cu.m./hr • Year of installation: 2003 • Drying unit area: 15.0 m2 Table 2: Technical data of solar tunnel dryer Parameters Value Width 2 m Length 18 m Air flow 400-1200 m3/h Air temperature 30-80°C Thermal energy gain up to 60 kWh/day Collector area 16 m² Drying area 20 m² Energy consumption 200 Wh/d Power requirement 20-40 W Width 1 m Length 2 m Air temperature 30-80°C Width 1 m Length 2 m Air temperature 30-80°C Width 1 m Length 2 m Air temperature 30-80°C Evaporative Cooling Pads: Use in Lowering Indoor Air Temperature Figure 1. Changes in air properties during evaporative cooling as shown on a psychrometric chart. Summer heat can cause indoor conditions to become much hotter than desired. Evaporative cooling is one way to reduce temperatures inside buildings. As water evaporates, it absorbs energy from the surrounding environment. A well-maintained ventilation system with evaporative cooling can reduce incoming air 10 to 20°F. Cooler indoor temperatures can improve the environment for plants and animals, plus significantly improve working conditions for employees. Evaporative cooling systems lower air temperature using mists, sprays, or wetted pads. Introducing water into ventilation air increases relative humidity while lowering the air temperature (see Figure 1). This fact sheet specifically describes systems that utilize wetted pads (see Figure 2). Evaporative Pad Cooling System دلمر په زور چلیدونکی د اوبو د تبخیر دلاری د کو لرانو سیستم Evaporative Pad Cooling System The typical evaporative pad cooling system (shown in Figure 3) draws outside air into the building through wet vertical pads. The major components of this system are: pad media, water supply, pump, distribution pipe, gutter, sump, and bleed-off line. As air flows past the moist pad surfaces, some of the moisture evaporates into the air stream. Heat is withdrawn from the air during this process and the air leaves the pad at a lower temperature with higher moisture content. د کولرانو دیزاین ډولونه DESIGN VARIATIONS There are two general methods of evaporative cooling: direct and indirect. Direct evaporative cooling involves the movement o f air past or through a moist material where evaporation, and therefore cooling, occurs. This cool moist air is then allowed to move directly to where it is needed. In contrast to this process, indirect evaporative cooling uses some form of heat exchanger that uses the cool moist air, produced through evaportive cooling, to lower the temperature of drier air. This cool dry air :s then used to cool the environment, and the cool moist air is expelled. In situations where cool dry air is more desirable than cool moist air, the extra effort or expense involved in building or buying and using a heat exchanger may be justified. On the other hand, many situations exist where it will be better to use the less complex and less costly direct evaporative cooling process. Evaporative cooling technology is used to cool rooms, homes, food, or water. The method of evaporative cooling used, direct or indirect, depends on: (1) the specific needs of the environ ment that will be cooled; (2) the availability and cost of com mercialenergy; and (3) the amount of money and skill available to buy or build the cooler. The followino discussion will present specific examples of how both methods of evaporative cooling can be applied. The advantages, disadvantages, and limitations of each of these applications are also examined INTRODUCTION Cooling through the evaporation of water is an ancient and ef fective method of lowering temperature. Both plants and animals use this method to lower their temperatures. Trees, through the process of evapotranspiration, for example, remain cooler than their environment. People accomplish the same thing when theyperspire. For both trees and people the underlying scientific principle is the same: when water evaporates, that is, changesfrom a liquid to a gas, it takes heat energy from the surrounding environment, thus leaving its environment cooler.
Posted on: Fri, 20 Sep 2013 07:22:50 +0000
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