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some renewable energy sources in the ASEAN region
1 SOME RENEWABLE ENERGY SOURCES IN THE ASEAN REGION & THEIR ENVIRONMENTAL IMPACTS Er Dr Adhityan Appan Technical Adviser LBW Consultants*; RJ Crocker Consultants *Blk 265, Serangoon Central Drive #02-273 Singapore 550265 Tel: +65 98003024 Fax: +65 63535248 Email: cappan@ntu.edu.sg 1.0 INTRODUCTION The use of fossil fuels indiscriminately and the damage that has been done to the environment is leaving mankind with no option but to resort to other sources of energy. Ideally these sources should be relatively easily renewable and readily available. However, special attention should be paid to ensure that they are not harmful to the environment and should in no way be cause for environmental damage in the future. The main objectives of this paper are: • to identify three main renewable energy sources that have potential and are being developed in the ASEAN region • to study recent installations and operations of such systems and their potential for creating environmental problems and • to draw conclusions on their current use and make recommendations to minimise environmental damage in the future. 2.0 MAJOR RENEWABLE RESOURCES IN THE ASEAN REGION The Asean region has a typically tropical climate which is hot and humid throughout the year. The range of temperatures is 15 to 40 o C and the average temperature is 29 o C (1). Since rainfall is largely seasonal, there are long dry periods in between. Such conditions are conducive for the effective harnessing and use of solar energy. Traditionally, in this region, solar energy has been predominantly used for heating water and drying purposes. However, penetration of solar photovoltaic (PV) systems has been growing across the region over the last ten years, where it is used mainly for electrifying rural and remote homes and villages. Most of Cambodia, the Philippines, Vietnam and some parts of Thailand have long coastal areas and also mountains from 2000 to 3000m high. These locations have been 2 identified as most suitable for the harnessing of wind energy, another renewable energy source (Cunanan, 2002). Asean countries lie mainly in the Southeast Asian region and span the equator. Since they are all under the influence of the Asiatic monsoons, they have abundant seasonal annual rainfalls in the range of 1000 to 5000 mm (2). Hence, in all these countries, there are rivers with perennial runoff. This has led to the construction and operation of hydro- electric projects varying in size from small to large to capacities (Bucta 2007, Battachary & Kumar2005). 3. ENVIRONMENTAL FACTORS AFFECTING SOME RENEWABLE ENERGY SOURCES 3.1 SOLAR ENERGY Silicon cells are still the most commonly used PV cells. Crystalline silicon cells are expected to continue as the dominant type for the next 5 to 10 years (Goetzberger, et al., 2003). The expected future trend in the PV industry is to produce more thin-film cells, which have potential for higher energy efficiency and hence lower cost per unit of electricity generated. 3.1.1 Factors influencing the Environment a. Energy: Energy is required to manufacture and install solar components and any fossil fuels used for this purpose will generate emissions. Thus, an important question is how much fossil energy input is required for solar systems compared to the fossil energy consumed by comparable conventional energy systems. Unlike fossil fuel-based technologies, solar power does not lead to any harmful emissions during operation, but the production of the panels leads to some amount of air pollution. b. Life Cycle Emissions: In the case of solar panels, the life-cycle greenhouse gas emissions are currently in the range of 35-45 g/kWh (Alsema et al, 2006) and this could decrease to 15 g/kWh in the future (Alsema et al, 2006a). The values for other sources are: For gas-fired Power Plant 400 g/kWh For Coal-powered Power plant 915 g/kWh For Nuclear Power 6-25 g/kWh 3 For Wind Turbines 11 g/kWh c. Health and Safety : Materials used in some solar systems can create health and safety hazards for workers and anyone else coming into contact with them. In particular, the manufacturing of some photovoltaic cells requires hazardous materials such as Arsenic and Cadmium. With respect to silicon-based cells, the primary concerns for human health are from the use of toxic gases and solvents during manufacturing. Arsine and phosphine gases are used in the production of silicon-based cells. The potential impacts are primarily at the manufacturing facilities for workers and for nearby residents, particularly if accidents occur. The completed, installed silicon-based cells pose minimal risks to human health or the environment. Even relatively inert silicon, a major material used in solar cells, can be hazardous to workers if it is breathed in as dust. Workers involved in manufacturing photovoltaic modules and components must consequently be protected from exposure to these materials. Cadmium is potentially of concern with the thin-film technologies. In its metallic form it is toxic and has the tendency to accumulate in ecological food chains. The amount of cadmium used in thin-film PV modules is relatively small in the range of 0.55-14 g/m² (Zweikbel et al, 1998) and with proper emission control techniques in place the cadmium emissions from module production can be almost zero Use of cadmium can generate cadmium-containing wastewater, and possibly cadmium fumes and dusts. At completed installations of photovoltaic systems for power generation, the potential for chemical releases appears to be small since the chemicals are present in the sealed PV modules. Releases are likely to occur only due to fires or other unusual accidents. Cadmium could be a potential concern in this setting with thin-film technologies, as would arsenic and zinc to a lesser extent. Leaching of metals from the installed modules is not likely to be of concern (Steinberger, 1998). Leaching from small cells used in electronic devices is also unlikely to be a concern, given the small amounts of chemicals present and the sealed nature of the devices. d. Disposal : Little information on disposal of used PV modules is available. Both cadmium and copper are a potential concern to biota due to their acute toxicity, depending on the conditions in a receiving waterbody and the specific type of biota. 3.2 WIND ENERGY 4 The earliest existence of windmills can be traced to the first century AD. (Drachmann, 1961). Windmills were used in Europe to grind flour in 12 th century and subsequent Dutch windmills still exist (Lohrmann, 1995). The modern wind turbine was developed in the 1980s and designs are still under development. 3.2.1 Factors influencing the Environment a. Water & Air Pollution: The operation of wind turbines does not involve activities resulting in or being cause for any form of water or air pollution. Besides, these turbines are also not involved in the production of any special toxic or hazardous substances other than those commonly found in identical large machines. b. Ice: This is an issue which caused concern mainly in Europe where there is the potential danger of ice being adhered to wind turbine blades. Due to the speed of rotation, vibration in the system and state of ice formation, ice can get detached and blown off the turbine blades. Detailed surveys and studies (Hassan G et al, 1998) have established that there has been no reported injury in spite of the installation of more than 600 mega Watts of wind energy world wide. It was concluded that the risk of anything or anyone being hit by ice from a wind turbine has a probability of a person being hit by a lightning strike in the UK. c. Noise: In wind turbines, the noise emitted can be due to the moving mechanical parts or due to revolution of blades. Modern wind turbines are very quiet machines in relation to their power and through their manufacturers’ continuing improvements keep getting quieter. It was observed that (Binopoulos, E & P. Haviarapoulos, 2005) the level of audible noise from a wind turbine, built to modern specifications, at a distance of 200 metres, is lower than the background noise level of a small town in the countryside and so is not considered as a nuisance. In addition, at the wind speeds in which wind turbines operate, the natural noise (from wind in trees and bushes) covers any noise emanating from them. Hence it can be safely concluded that wind farms do not cause an increase in the existing noise level outside their boundaries and even less in residential areas. d. Early problems associated with bird deaths: The Altamont Pass Wind Farm is one of the earliest in California, USA installed after the 1970s energy crisis and in response to favorable tax policies for investors. It is composed of over 4900 relatively small wind turbines of various types and is still the largest concentration of wind turbines in the world, with a capacity of 576 megaWatts (Lowitz, 2008). Bird deaths from electrocution or collisions with spinning rotors emerged as a problem during a three-year period. To appraise the magnitude of bird deaths dozens of studies spanning nearly two decades were undertaken and it is now known (Sagrillo, 2003) that the Altamont Pass situation is an unusual case. The high raptor mortality there was the result of a convergence of factors, some of which were due to the bad siting in the local ecosystem while others were due to the wind turbine and tower technology used at the time. The NWCC Reports (2003) finally established that commercial wind turbines cause the direct deaths of only 0.01% to 0.02% of all of the birds killed by collisions with man-made structures and activities in the U.S 5 e. Visibility & effect on Landscape: Visual disturbance is largely subjective and it is difficult to set standards which will be accepted by everyone. Particularly near populated areas, wind projects often run into stiff opposition from people who regard them as unsightly and noisy, or who fear their presence may reduce property values. f. Effect of Wind Turbines on Farm stock: There is no indication that wind farms have a negative impact on farming or livestock. Wind turbines are normally spaced a certain distance apart and the land in between should be regarded as occupied. Hence, it is clear that farming can continue after the wind farm has been built. The usual sites for wind farms are in mountainous areas with low vegetation. In these areas, the land is used mainly as pasture for sheep and goats, which can continue unhindered after the wind farm has been built.(ref : Greece paper) Besides this, the leasing of land for wind turbines, can bring substantial benefits to landowners in the form of increased income and land values. In other settings, however, wind power development can create serious land-use conflicts. In forested areas it may mean clearing trees and cutting roads, a prospect that is sure to generate controversy, except possibly in areas where heavy logging has already occurred. 3.3 HYDRO POWER The use of hydro power in the form of hydro-electric schemes has gained prominence since the early twentieth century and such schemes have continued to become larger. The USA alone currently has over 2,000 hydroelectric power plants which supply 49% of its renewable electricity. (3). 3.3.1 Factors influencing the Environment a. Emissions: Hydropower is an energy source that makes it possible to produce electricity without using fossil fuels, and is subsequently not part of the emissions (like Carbon dioxide and other gases) caused by electricity production in coal, oil, or gas fired power plants. b. Encroachment on Nature : The environmental consequences of the construction of a dam to harness hydropower are bound to have an impact on nature due to encroachment. Hence, modern hydropower projects normally take environmental concerns into consideration thus making the change in river regulation as gentle as possible on nature. Some of the salient factors are: (i) Changed water flow : Hydropower projects will affect the water flow in river systems. But it is still possible to have a healthy fish stock in a regulated river system. In fact, many of Norway’s best fishing rivers are regulated. (ii) Changes in Water Level: Changes to the water level throughout the year can lead to scouring of fine substances and nourishment and cause erosion along the shoreline. 6 (iii) Ecosystems: Dams can cause radical changes in river ecosystems both upstream and downstream and within the reservoir (iv) Initial Filling of Dam: Damming areas with rich, biodiverse flora also risks a negative effect on the climate because of large amounts of carbon that are tied to trees and other plants which are released when the water reservoirs are filled with water for the first time and these crops rot without the help of oxygen. This leads to the creation of methane. (v) Building of roads and power lines: When power plants are built, there will necessarily be some physical encroachment close to the construction roads, such as the establishment of industrial structures in natural settings. These encroachments can be offset by obliging the constructor to replant the landscape, so that the encroachments will be as gentle and minimally intrusive as possible. (vi) Spoiling of natural landscape: Power lines are alien substances in nature and can ruin natural landscapes. They can affect the bird population, either through collision or by short circuit due to contact. Conversely, when power transmissions are installed as underground cables, digging and blasting of ditches affect the hydrology and vegetation of the area. (vii) Recreation Areas: Damming of large areas reduces public access to certain areas, and thereby affects outdoor recreation opportunities. On the other hand, in some of the impoundments controlled water-associated activities such as boating, fishing, swimming can allowed. (viii) Resettlement: Due to a large area that will be inundated, there will be the need to resettle those people who are affected. In the case of the Three Gorges dam in China this population has been estimated to be as much as 1.2 million (Kennedy, 2001). Compensating these people and finding appropriate jobs and resettling them in different locations will become one of the major social issues. (ix) Eutrophication in reservoirs : In case the waste loads in the rivers are high, damming & storage could result in a change in the trophic state of the reservoirs. Consequently, there can be unsightly weeds, hyacinth etc besides which the reservoir water quality will also be largely affected. (Appan, 2007) 4. DISCUSSION & CONCLUSIONS 4.1 Solar Energy: • None of the hazards encountered in the production, use and disposal of PV systems is much different in quality or magnitude from the innumerable hazards people face routinely in an industrial society. Through effective regulation, the dangers can very likely be kept at a very low level 7 • The large amount of land required for utility-scale solar power plants (about 1 sg.km for every 20-60 megaWatts generated) poses an additional problem, especially where wildlife protection is a concern. But this problem is not unique to solar power plants as generating electricity from coal actually requires as much or more land per unit of energy delivered. Likewise, hydro-power plants can also make large demands with respect to land areas that will be inundated. • Recycling is expected to be the preferred disposal option for spent PV modules in the future, in order to minimize environmental impacts, reduce disposal costs of spent modules, and recover source metals. • PV systems are in a good position to compete with other conventional energy technologies in terms of life-cycle greenhouse gas emissions (Tetra Tech Inc, 2003) • With added problems like climate change on a global basis associated with the dwindling non-renewable sources, the future utilization of solar energy which is the biggest renewable source available to mankind is going to be an inevitable option. (Appan, 2009) 4.2 Wind Energy • While it is established that the use of wind turbines are benign with respect to water and air pollution, its impact in terms of noise and bird deaths are minimal. • Their effect on land use is also largely beneficial. • However, if future expansions impinge on this area, with imagination, careful planning, and early contacts between the wind industry, environmental groups, and affected communities, siting and environmental problems should not be insurmountable. 4.3 Hydro Power • Hydropower produces no carbon dioxide or other harmful emissions, in contrast to burning fossil fuels. • Hydroelectric power can be far less expensive than electricity generated from fossil fuels or nuclear energy. • Areas with abundant hydroelectric power attract industry. • The chief advantage of hydroelectric dams is their ability to handle seasonal (as well as daily) high peak loads. When the electricity demands drop, the dam simply stores more water which provides more flow when it is released. • Impounding reservoirs resulting from the building of dams for massive hydro- electric schemes can lead to a host of problems associated with the change in regime of the original river, massive resettlement, eutrophication of the water body etc. However, these problems have been well-defined over the years and can be dealt with adequately by proper pre-planning and liaison with the 8 appropriate authorities during the construction and operation stages of such projects. REFERENCES 1. http://www.retire-asia.com/asia-weather.shtml 2. http://en.wikipedia.org/wiki/Hydroelectricity 3. http://en.wikipedia.org/wiki/Hydroelectricity Alsema E A & Wild-Scholten M J de, 2006. “Environmental Impacts of Crystalline Silicon Photovoltaic Module production” Presented at the 13 th CIRP International Conf on Life Cycle Engineering, Leuven, 31 May – 2 June. 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