Waste to Energy in India

Posted on April 9, 2008 by Rashid Faridi

An estimated 30 million tonnes of solid waste and 4,400 million cubic meters of liquid waste are generated every year in the urban areas of the country. This estimation is based on the structured data base prepared for 299 Class I cities and 36 Class II cities as part of “National Master Plan for Development of Waste to Energy in India” being taken up under UNDP/GEF assisted Project on “Development of High Rate Biomethanation Processes”. The study concluded that 17(6%) cities have generation rate in excess of 1000 TPD, and 80 cities (26%) generate 150 to 1000 TPD. The balance 202 cities (68%) individually generate less than 150 TPD. The municipal solid waste (MSW) generation ranges from 0.25 to 0.66 kg/person/day with an average of 0.45 kg/person/day. In addition, large quantities of solid and liquid wastes are generated by industries. Most of the wastes generated find their way into land and water bodies, without proper treatment, emitting gases like Methane (CH4), Carbon Dioxide (CO2), etc, resulting in bad odour, air and water pollution, as well as increase in the emission of green house gases. This problem can be significantly mitigated through adoption of environment-friendly waste-to-energy technologies for treatment and processing wastes before disposal. It not only reduces the quantity of wastes, but also improves its quality to meet the required pollution control standards, besides generating substantial quantity of energy.

The Ministry of Non-Conventional Energy Sources is promoting setting up of Waste-to-Energy projects in the country through two schemes namely i) National Programme on Energy Recovery from Urban and Industrial Wastes and ii) UNDP/ GEF assisted Project on Development of High Rate Biomethanation Processes as a means of Reducing Green House Gases Emission.

National Programme

The National Programme on Energy Recovery from Urban & Industrial wastes, launched during the year 1995-96, has the following objectives:

a) To promote setting up of projects for recovery of energy from wastes of renewable nature from Urban and Industrial sectors; and

b) To create conducive conditions and environment, with fiscal and financial regime, to develop, demonstrate and disseminate utilisation of wastes for recovery of energy.

c) To develop and demonstrate new technologies on waste-to-energy through R&D projects and pilot plants.

The scheme is applicable to private and public sector entrepreneurs and organisations as well as Non-Governmental Organisations (NGOs) for setting up of waste-to-energy projects on the basis of Build, Own & Operate (BOO), Build, Own, Operate & Transfer (BOOT), Build, Operate & Transfer (BOT) and Build Operate Lease & Transfer (BOLT). It is being implemented through State Nodal Agencies, who forward the Detailed Project Reports, received from the promoters, to MNES along with their recommendations in respect of financial, managerial and technical capabilities of the promoters and on assured availability of waste materials on a long term basis (over 10 years) for operating the project smoothly.

During 2004-05, projects based on industrial wastes were entitled to interest subsidy for reducing the rate of interest to 4% for special category States and 6% for other States on the loans availed by promoters through financial institutions. Besides, incentives to State Nodal Agencies for their involvement and facilitating in execution of the projects were included under the scheme. The financial support for municipal solid wastes based projects which was available during 2002-03 (capital subsidy of 50% of the cost of projects limited to Rs.3.00 crore per MW for demonstration projects and interest subsidy for commercial projects) and was under review for rationalisation.

A total of three projects based on palm oil industry waste, cattle dung & poultry waste were completed and commissioned during the year. The installed capacity of these projects was 5.00 MW, thus making the cumulative installed capacity of waste to energy projects in the country to around 46.50 MW till 31.12.2004. Out of these three projects commissioned during 2004-05, two were under the National Programme and their salient details are given below. The third project was completed under the UNDP/GEF project.

3.0 MW power project based on Palm Oil Industry Waste by M/s Sai Renewable Power Pvt. Ltd. Hyderabad, at Eluru, District West Godavari, A.P: The plant has been set up based on combustion of empty bunches from palm trees and residues of palm fruits. These remains are rich in volatile substances and will be used as a fuel for the boiler in the plant. About 100 tonnes per day of palm oil industry waste is being used to produce 3 MW of power. The total cost of the project is Rs.1376 lakh out of which 70% has been taken as soft loan from IREDA and the rest as promoter’s equity. The Ministry has provided interest subsidy to IREDA on the loan provided to the promoters. The officials of MNES have visited the project and it has been working satisfactory to the capacity.

1.5 MW power project based on poultry droppings at Namakkal, Tamil Nadu : The plant has been installed by M/s G. K. Bio-Energy Pvt. Ltd., Namakkal, based on biomethanation technology to generate power using poultry droppings from one million birds of nearby poultry farms. It is based on BIMA (Biogas Induced Mixing Arrangement) technology developed and commercialised by M/s Entec, Austria. The engines used for generating power are 100% biogas engines imported from Austria. The total cost of the project is Rs.1804 lakh, out of which about 50% is IREDA’s loan at commercial rate, 30% is promoters’ equity and about 20% is capital subsidy from MNES, which is being provided as interest free loan in the beginning to be converted into capital subsidy after successful completion of the project. The project has been commissioned very recently.

The project which was under various stages of installation during the year is as below:

2.5 MW Power Generation Project based on Poultry Droppings at Namakkal, Tamil Nadu: A project for generation of 2.5 MW power and 50 tonnes per day bio-fertilizer utilising about 600 tonnes of poultry droppings per day has been sanctioned to M/s Subhashri Bio-energies Pvt. Ltd. (SBPL), Namakkal, Tamil Nadu. The project is based on the indigenous anaerobic process developed by the promoter and its total cost is Rs.24.69 crore. The Ministry is providing a capital subsidy of Rs.600 lakh @ Rs.3.00 crore per MW by considering the project as a demonstration project and Indian Overseas Bank (IOB) have sanctioned the term loan of Rs.1308.34 lakh. The balance amount is being mobilised by the promoter as its equity. The Structural Engineering Research Centre (SERC), Chennai have been retained as consultant for vetting of structural design of the digesters and for supervision during the construction. The project execution is currently under progress and is likely to be commissioned by June 2005

In addition to the above progress on a few completed projects was continuously monitored whose details in brief are as below:

5 MW municipal solid waste (MSW) based project at Lucknow: The project has been executed by M/S Asia Bio-energy Pvt. Ltd (ABIL), Chennai on Build, Own, Operate and Maintenance basis in association with Lucknow Nagar Nigam (LNN) who are responsible for supply of required quality and quantity of MSW at the plant site. The plant based on Biomethanation technology started its commercial operation in August 2003 but could reach to a maximum generation capacity of 1.5 MW only by March 2004. The plant is presently facing problem in its operation mainly due to non-availability of the required quality of MSW free from debris, sand & silt. To solve the problem of waste supply, a meeting of the High Level Monitoring Committee, constituted for the project was held on 19th January, 2005 under the Chairmanship of Secretary, MNES wherein time bound action points were chalked out for implementation by the LNN and ABIL. It is expected that the problem of waste supply will be solved and the plant will start operating to its capacity soon.

6 MW MSW based power plant at Vijayawada: The project based on combustion technology has been executed by M/s Sriram Energy Systems (P) Ltd., Hyderabad by availing a soft loan from Technology Development Board (Department of Science and Technology) and Indian Renewable Energy Development Agency (IREDA). It was commissioned in December 2003 and is reported to be operating to its full capacity with a mix of 30% of rice husk with MSW. The total electricity generated till November 2004 was 25 million units out of which 21 million units has been exported to the grid. Total MSW treated was around 50,000 Metric tonnes.

6 MW Municipal Solid Waste Project at Andhra Pradesh: Another project based on MSW on similar technology commissioned in November, 2003 by M/S SELCO International, Hyderabad has been reported to be operating successfully. It is reported that around 28 million of units of electricity has been generated till December 2004 by treating around 1 million metric tonnes of MSW since inception. The project was completed in 2 phases; one for preparation of pallets from MSW and the other for power generation from
MSW pallets.

A few proposals for setting up of Waste-to-Energy Projects, which were accorded ‘in-principle’ approval by the Programme Advisory Committee for Waste-to-Energy Programme during previous years were monitored for their progress in obtaining financial closure and other clearances from various organisations by the promoters before they are processed for necessary support from the Ministry. The projects envisage setting up of power projects based on poultry droppings, starch industry waste, sugar cane press mud, furfural industry waste and municipal solid wastes with an aggregate capacity of about 25 MW.

Two new proposals for setting up of projects based on municipal solid waste in Surat and Rajkot were developed which are also in the process of obtaining necessary clearances and other tie-ups made with different organisations. A few proposals for setting up of power generation plants from the biogas available at existing Sewage Treatment Plants in Surat were also developed by the Surat Municipal Corporation, which are to be supported under the programme.

UNDP/GEF Project
The UNDP/GEF project was started during September 1994 with the objectives to set up demonstration sub-projects, preparation of National Master Plan, capacity building and publication of a quarterly newsletter ‘Bio Energy News’. The project is being implemented with the association of a few eminent National laboratories and institutions for providing assistance in the biomethanation technology related to issues like design, analysis of critical aspects of construction, supervision, commissioning, trouble shooting, monitoring and evaluation of projects at the demonstration stage. In addition, a couple of State Nodal Agencies have also been associated to act as implementing agencies for a few sub-projects. The waste sector considered for developing sub-projects under the programme are: i) Pulp & Paper Industry Effluent ii) Leather and Slaughterhouse Industry Wastes, iii) Vegetable Market yard Wastes, iv) Sewage/Municipal Waste Water, v) Animal Manure, vi) Starch and Tapioca Processing Industry Wastes and vii) Biogas Utilisation for power generation.

A total of 15 sub projects have been taken under UNDP/GEF project out of which 12 were already completed till 2003-04. During the year 2004-05 one more project was commissioned and its brief report is as below:

1.0 MW power project based on cattle manure at Haebowal Dairy Complex Ludhiana, Punjab: Haebowal Dairy Complex in Ludhiana, spread over an area of 50 acres, has 1490 dairies with an animal population of 1,50,000 and generate about 2500 tonnes of animal droppings. The project, based on BIMA technology, has been designed to use 235 tonnes of animal waste for generating about 0.965 MW electrical energy, most of which will be for captive use. The plant started power generation in August 2004 and has been operating at 60% of its capacity. The surplus energy after meeting the in-house power requirement is being fed to the state electricity grid. Besides, electrical energy, the project will also be producing about 75 tonnes of stabilised organic manure per day. The project is being implemented by PEDA, the State Nodal Agency with 50% financial contribution from the State Government. Constant monitoring of the project was ensured by organising meetings of the Project Steering Committee and through site visits.

Two other projects, which were under various stages of implementation, are as under:

0.5 MW power project based on slaughterhouse solid waste at M/s Hind Agro Ltd., Aligarh, U.P: M/s Hind Agro has a 100% export oriented modern integrated abattoir cum meat processing plant at Aligarh. The biogas plant being installed at their place is designed to treat solid waste generated from slaughtering of 1600 buffaloes everyday. The project for biomethanation of slaughterhouse solid wastes to produce about 4000 cum. biogas per day for generation of 0.5 MW power from about 50 tonnes per day solid wastes is under installation at M/s Hind Agro Ltd., Aligarh. The plant is being installed by M/s RSB Japan on turnkey basis under the technical supervision of Central Leather Research Institute, Chennai. All major indigenous as well as imported equipment have been installed at the site and civil work is nearing completion. The project is likely to be completed by June 2005. Regular monitoring of the project was carried out through meetings of the Steering Committee and site visits.

0.3 MW power project utilising vegetable market wastes at Koyembedu Market Complex, Chennai: The Biomethanation plant being installed at Koyembedu Market Complex (KMC), Chennai is expected to treat about 30 tonnes of Vegetable Market Wastes per day for generation of around 0.3 MW of power. The

estimated generation of biogas from the plant is about 2500 cum., besides generation of around 9-10 tonnes of organic manure having moisture content of 25-30% per day. The biogas produced will be utilised in a 230 kW imported gas engine having in-built co-generating unit for generation of electricity and thermal energy. The project is likely to be completed by March 2005. It is being implemented by Chennai Metropolitan Development Authority under the technical supervision of CLRI, Chennai. The installation of the plant is being done by M/s Enkem Engineers Pvt. Ltd, Chennai on turn-key basis. Project activities were monitored by making visits and organising meetings of the Project Steering Committees at the project site.

To explore the possibility of treating MSW at decentralised level in urban areas, details of smaller size biogas plants working on mixed urban waste in the range of 1-10 tonnes per day were collected from various suppliers/ technical institutions. One such technology has been developed by Bhabha Atomic Research Centre (BARC) and has been uccessfully implemented in the field. The technology is a modified KVIC biogas plant with two modifications made as detailed below so as to treat mixed biodegradable waste.

i) A 5 HP mixer has been introduced to process the waste before putting it into pre-digester tank. The waste is converted in slurry by mixing it with water (1:1). Usually this is the failure point as solid waste is too difficult to digest and can easily clog a system.

ii) Use of thermophilic microbes for faster degradation of the waste through aerobic process. The growth of thermophiles in the pre-digester tank is assured by mixing the waste with hot water and maintaining the temperature in the range of 55 to 60°C. The hot water supply is from solar heater/ biogas boiler.

To further improve upon this technology and standardise the design parameters for its large-scale promotion in the country, financial support was provided to BARC under UNDP project during the year. The outcome of the project is expected to be delivered by the end of financial year 2004-05.

National Master Plan: A National Master Plan (NMP) for Development of ‘Waste-to-Energy Programme’ in India, is being prepared through a consultancy organisation namely M/s Montgomery Watson Harza (MWH), Mumbai, as part of the UNDP/GEF assisted Project on “Development of High Rate Biomethanation Processes” The overall structure of NMP is to prepare a Road Map for Recovery of Energy from Wastes during the next 15 years. The draft document on the National Master Plan prepared during 2003-04 was discussed with all the stakeholders in a conference organised in Delhi on 29th April 2004 and is now under finalisation. The conference was attended by 60 officials from Central & State Governments, NGOs, financial & technical institutions, promoters, UNDP project beneficiaries, consultants, etc. The NMP is available on website: http://www.indiawteplan.com

Bio Energy Newsletter: A quarterly newsletter “Bio Energy News” (BEN) is being published on a regular basis since September 1996. The Newsletter focuses on developments taking place in the field of waste processing and treatment technologies, waste management practices, bio-energy, etc. Two issues of this newsletter were published during the year. BEN is also available on the website of MNES (www.mnes.nic.in) as well as that of UNDP (www.undp.org).

New R&D Projects
Two new R&D projects viz. (i) Demonstration of sulfdry process – a low cost hydrogen sulphide removal system for power generation: by M/s Engineers India Ltd., Gurgaon and (ii) Applied R&D applications of USAB system and energy recovery from tannery wastewater at CETP Dindigul, Tamilnadu: by CLRI, Chennai have been initiated during this year with financial participation from other stakeholders.

Other Activities
A National seminar on ‘Biomass based decentralised power generation’ organised by SPRERI, Vallabh Vidyanagar was attended by U&I Group official on 21st January 2005 wherein a status of the Ministry’s programme on Waste to Energy in the country was presented among the participants.

A presentation on ‘UNDP/GEF assisted Project on Development of High Rate Biomethanation Processes’ was made by the U&I Group officials in the UNDP/GEF session on ‘Integrating Global Environmental Issues into National Development Agenda’ at International Congress on Renewable Energy (ICORE-2005) organised by SESI at Pune during 20-22nd January 2005.

A Meeting was convened by the Ministry of Urban Development at New Delhi on 17th December 2004 with technology experts and developers to discuss various technological options available for the treatment and disposal of municipal solid wastes in a scientific and hygienic manner. The meeting was attended by the U&I Group officials.

A visit to 6 MW capacity MSW based power plant and RDF preparation plant based on MSW installed by M/s SELCO International at Hyderabad was made by the members of the Parliamentary Committee on Energy during 17-18th October, 2004. Officials of MNES and State Government accompanied the Parliamentary Committee. The Committee appreciated the initiative taken by M/s SELCO International in treating the MSW of Hyderabad City by way of installation of these plants.

To promote renewable energy devices including Waste to energy projects in urban areas, a national conference was organised in Delhi on 6th September 2004, which was attended by the Mayors, Municipal Commissioners of the country. A separate session on waste to energy was conducted in the conference wherein presentations on two projects, one on 6MW capacity power plant based on MSW combustion technology at Hyderabad, the other on 5MW capacity power plant based on MSW Biomethanation technology were made by the concerned promoters.

source:http://mnes.nic.in

Posted in Environment, Urban Studies | 100 Comments

Tidal power – energy from the sea

Posted on April 9, 2008 by Rashid Faridi

The Movement of the Sea could be a huge energy source.

The tide moves a huge amount of water twice each day, and harnessing it could provide a great deal of energy – around 20% of Britain’s needs.

Although the energy supply is reliable and plentiful, converting it into useful electrical power is not easy.

There are eight main sites around Britain where tidal power stations could usefully be built, including the Severn, Dee, Solway and Humber estuaries.

Only around 20 sites in the world have been identified as possible tidal power stations.

How it works: Tidal Barrages

These work rather like a hydro-electric scheme, except that the dam is much bigger.A huge dam (called a “barrage”) is built across a river estuary. When the tide goes in and out, the water flows through tunnels in the dam. The ebb and flow of the tides can be used to turn a turbine, or it can be used to push air through a pipe, which then turns a turbine. Large lock gates, like the ones used on canals, allow ships to pass.

If one was built across the Severn Estuary, the tides at Weston-super-Mare would not go out nearly as far – there’d be water to play in for most of the time.

But the Severn Estuary carries sewage and other wastes from many places (e.g. Bristol & Gloucester) out to sea. A tidal barrage would mean that this stuff would hang around Weston-super-Mare an awful lot longer! Also, if you’re a wading bird that feeds on the exposed mud flats when the tide goes out, then you have a problem, because the tide won’t be going out properly any more.

 a tidal barrage

More details

The largest tidal power station in the world (and the only one in Europe) is in the Rance estuary in northern France. It was built in 1966. A major drawback of tidal power stations is that they can only generate when the tide is flowing in or out – in other words, only for 10 hours each day. However, tides are totally predictable, so we can plan to have other power stations generating at those times when the tidal station is out of action. Tidal power station in France

There have been plans for a “Severn Barrage” from Brean Down in Somerset to Lavernock Point in Wales. Every now and again the idea gets proposed, but nothing has been built yet.

It may have over 200 large turbines, and provide over 8,000 Megawatts of power (that’s over 12 nuclear power station’s worth). It would take 7 years to build, and could provide 7% of the energy needs for England and Wales.

There would be a number of benefits, including protecting a large stretch of coastline against damage from high storm tides, and providing a ready-made road bridge. However, the drastic changes to the currents in the estuary could have huge effects on the ecosystem.

Another option is to use
offshore turbines,
rather like an underwater wind farm. This has the advantage of being much cheaper to build, and does not have the environmental problems that a tidal barrage would bring. There are also many more suitable sites.

Find out more about the world’s first offshore tidal power station at www.marineturbines.com/technical.htmPicture courtesy of marineturbines.com

The University of Wales Swansea and partners are also researching techniques to extract electrical energy from flowing water. The “Swanturbines” design is different to other devices in a number of ways. The most significant is that it is direct drive, where the blades are connected directly to the electrical generator without a gearbox between. This is more efficient and there is no gearbox to go wrong. Another difference is that it uses a “gravity base”, a large concrete block to hold it to the seabed, rather than drilling into the seabed. Finally, the blades are fixed pitch, rather than actively controlled, this is again to design out components that could be unreliable.Find out more at www.swanturbines.co.uk
Yet another option:
vertical-axis turbinesFind out more from the Canadian company Blue Energy at www.bluenergy.com

 

Advantages

  • Once you’ve built it, tidal power is free.
  • It produces no greenhouse gases or other waste.
  • It needs no fuel.
  • It produces electricity reliably.
  • Not expensive to maintain.
  • Tides are totally predictable.
  • Offshore turbines and vertical-axis turbines are not ruinously expensive to build and do not have a large environmental impact.

 

Disadvantages

  • A barrage across an estuary is very expensive to build, and affects a very wide area – the environment is changed for many miles upstream and downstream. Many birds rely on the tide uncovering the mud flats so that they can feed. There are few suitable sites for tidal barrages.
  • Only provides power for around 10 hours each day, when the tide is actually moving in or out.

 

Is it renewable?

Tidal energy is renewable. The tides will continue to ebb and flow, and the energy is there for the taking.

source:http://home.clara.net

Posted in Uncategorized | 2 Comments

Southeast Asean Rainforest

Posted on April 9, 2008 by Rashid Faridi
Photograph by © WWF-Canon/William F. RODENBURG

The Southeast Asian rainforests are the oldest, consistent rainforests on Earth, dating back to the Pleistocene Epoch 70 million years ago. It has a biological richness and diversity unequaled by that of the Amazon or African rainforests. Yet Southeast Asia is losing its rainforests faster than any equatorial region, and has the fewest remaining primary rainforests. It is projected that most of the primary rainforests of Southeast Asia will be destroyed in the next 10 years.

Southeast Asia is a 3,100 mile long chain of about 20,000 islands strung between Asia and Australia. It covers and area of 1,112,000 square miles, almost twice the size of Alaska. The area lies from latitude 20° north and 16° south, and longitude 95° to 105° east. The average daily temperature varies from 70°F to 90°F. Humidity is always high.

Millions of years ago, as the rest of the world went through cooling and warming periods, the climate of the Southeast Asian region remained more or less the same. This was due mainly because of its location on the equator and being surrounded by water. Because the climate on the equator doesn’t change much and the surrounding oceans provide plenty of moisture in the form of rain, the region was able to have consistent forests over very long periods of time. As sea levels rose and fell through warming and icing cycles, small pockets of forests survived as “forest refugia”, or reservoirs of wildlife from which various species could reestablish themselves. Malaysia and the islands of Borneo, Sumatra and Java were all part of the same landmass during the last ice age. When the glaciers melted and sea levels rose many of these reservoirs were cut off from each other. This forced species to developed their own distinctive evolutionary paths in response to local environments, leading to an amazing diversity of species of every kind.

One interesting feature of the lowland rainforests of Malaysia, Borneo and Sumatra is the dominance of one family of trees, the Dipterocarpaceae. Dipterocarp are emergent trees and can reach heights of 120 feet. Their crowns are supported on large straight trunks. Many epiphytes, like orchids and ferns grow on the trees. Lianas, vines and strangler figs cling to the trees as they grow towards the sunlight. The emergent species is the tualang (Koompassia excelsa)which can reach heights of 280 feet. It is the 3rd tallest tree species in the world, and is almost never cut down because of its hard wood and massive buttresses. But most importantly it is home to large honey bees (Apis dorsata)whose honeycombs hang like enormous wedges from the underside of its branches. These trees are worth more money when left standing.

Trees and shrubs in the lower canopy have elongated crowns as the leaves reach for light. Shade tolerant species flourish here. Leaves are set at the best angle to receive light. Special swollen joints at the base of the stem, called pulvinus, rotate the leaf to follow the sun.

On the forest floor the soil is shallow with most nutrients close to the surface. Leaf litter and dead trees are quickly consumed and broken down by fungi, insects, and other decomposers. The nutrients decomposition creates are immediately taken up by the biomass of the forest. Because the nutrients are close to the surface, roots don’t grow down very far, and trees have adapted by growing buttressed roots up to 30 ft high, or stilt roots which hang down from their trunks and branches.

There are many mutualistic relationships within the ecosystem of the rainforest. Dawn Bats are the prime pollinators of the durian tree. Each of the hundreds of fig species have their own species of pollinating wasp (Agaoninae spp), without which they would quickly fade into extinction and vise versa. Silvery Gibbons (Hylobates moloch)live their entire lives in the high canopies of the dipterocarp forests, never descending to the ground. Their survival depends on the dipterocarp and fig trees which house and feed them throughout the year. Links within the tropical rainforest ecosystem extend to thousands of plants which support mammals and birds. If a keystone species is eliminated, additional losses will be triggered and create a dominoes effect of extinctions.

Trees don’t flower and come into fruit at the same time in the Southeast Asian rainforest. Some trees only fruit once every three years, some only every ten year. The short nutrient cycle makes it difficult for trees to produce large amounts of fruit at regular intervals. Many trees complete the flowering cycle in only one day, and are only receptive for a few hours during the day or night. Very few trees depend on the wind for pollination since there is little air under the dense canopy. These trees depend on animals and insects to pollinate and disperse their seeds. Emergent trees like the Kapok (Ceiba pentandra), dipterocarps, or Tualang which can grow to heights of 240 ft, can afford to have air-borne seeds. Their crowns grow high above the canopy and are exposed to the winds that blow there.

When seeds drop to the ground they almost always need to germinate in shady conditions. The forest floor is a difficult place to begin life, and many seeds surround themselves with fleshy, aromatic pulp as an immediate source of food. Smell plays an important part of a plant’s life cycle, and many plants will have strong smelling flowers and fruits. The Rafflesia smells like a rotting corps, and the durian fruit smells almost too bad to eat, although it is known as the King of Fruit and tastes delicious. The powerful smell attract animals and insects that eat and disperse the seeds far from their parent tree.

Hundreds of animal and plant species are on the brink of extinction in Southeast Asia. The critically endangered two-horned Sumatran rhinoceros survives in small forest pockets of Sumatra and Borneo. Their entire population is thought to be only 300 to 500 individuals. The Javan rhinoceros has already slipped into extinction. The Sumatran tiger, like its cousin the Javan tiger will soon be extinct as well. The Asian elephant is another large forest herbivore which needs large amounts of forest to survive. Human encroachment and logging are shrinking their habitat to the extent that they can no longer support the elephants. The Malayan tapir is the largest of the 4 species of tapir still alive and no more than 50 animals still live in the wild. Another animal found only on Sumatra and Borneo is the orangutan, or “man of the forest”. They were once found on mainland Asia from Thailand to southern China. They feed mostly on fruit and move through the forest following the fruiting trees. There are thirteen separate species of primates in Borneo’s lowland forests alone. Most have overlapping home ranges but have different diets and foraging methods.

The climate of Southeast Asia is classified as a tropical wet climate in the Köppen climate zone system. The climate is influenced by maritime wind systems which originate in the Indian Ocean and the South China Sea. It has two monsoon seasons. The northeastern monsoon occurs from October to February and brings heavy rains to the eastern side of the islands. These storms carry the same punch as Atlantic hurricanes but spend much of their energy over the Phillipines. The southwestern monsoon is more powerful and occurs from April to August. Heavy rains saturate the western side of the island chain. Rain shadow effects create dryer but windy conditions on the opposite sides of the islands and the Malaysian peninsula during monsoon seasons. There are two inter-monsoon seasons between the two main monsoon seasons. Southeast Asian rainforests get an average of 79 inches of rain annually.

Any change in the monsoon cycle can have devastating results. In 1992-1993 one of the largest fires ever burned in Kalimantan. Widespread logging had degraded the primary forest and made it prone to fire. The drought brought on by the El Niño of that year created a catastrophe when agricultural fires got out of control. Twentyseven thousand square km burned out of control.

The same events unfolded in 1998. The El Niño of that year created a very weak monsoon season. Thousands of forest fires burned over Malaysia and the Indonesian archipelago, destroying rainforests and the plants and animals within them. A haze of smoke spread for thousands of miles across the region. Untold mutualistic relationships may have been destroyed, keystone species eliminated. It is still unclear what effects the events of 1998 had on the ecosystem of the rainforests. Unfortunately, in the year 2002 another strong El Niño is developing over the Pacific.

Political instability in the Indonesian archipelago has resulted in little law enforcement within protected wildlife areas. In 1992, feeling betrayed by the government of President Suharto, local people took control of the land and began indiscriminate logging and farming in the dipterocarp rainforests. Little regard has been given for the long-term environmental effects, and at the present rate of destruction there will be no primary lowland rainforests remaining in Indonesian Borneo by the next decade.

In Indonesia illegal logging has led to a “biological catastrophe” affecting thousands of plant and animal species and upsetting the natural biologic equilibrium that keeps a rainforest healthy and stable. The mutualism that sustains numerous species has been destabilized and could lead to massive extinctions. For the plants and animals and the myriad species that inhabit the rainforests of Southeast Asia it may be too late and there is no “forest refugia” left from which to replenish their species. Fragmentation of habitats will cause more interaction of animals with humans, and many animals will be killed or captured for the pet trade. Huge numbers of species will become extinct before their role in the rainforest will have become known, and the rainforest ecosystem of Southeast Asia will collapse.

source:http://www.blueplanetbiomes.org
Posted in BIODIVERSITY, Natural Resources, Uncategorized | Leave a comment

Geothermal Energy

Posted on April 8, 2008 by Rashid Faridi

WHAT IS GEOTHERMAL ENERGY?

The word geothermal comes from the Greek words geo (earth) and therme (heat). So, geothermal energy is heat from within the earth. We can use the steam and hot water produced inside the earth to heat buildings or generate electricity. Geothermal energy is a renewable energy source because the water is replenished by rainfall and the heat is continuously produced inside the earth.

ENERGY INSIDE THE EARTH

Image of the earth's interior, from the outside to the inside, with the crust, the mantle of magma and rock, the outer core of magma, and the innermost core of iron.Geothermal energy is generated in the earth’s core, about 4,000 miles below the surface. Temperatures hotter than the sun’s surface are continuously produced inside the earth by the slow decay of radioactive particles, a process that happens in all rocks. The earth has a number of different layers:

  • The core itself has two layers: a solid iron core and an outer core made of very hot melted rock, called magma.
  • The mantle which surrounds the core and is about 1,800 miles thick. It is made up of magma and rock.
  • The crust is the outermost layer of the earth, the land that forms the continents and ocean floors. It can be three to five miles thick under the oceans and 15 to 35 miles thick on the continents.The earth’s crust is broken into pieces called plates. Magma comes close to the earth’s surface near the edges of these plates. This is where volcanoes occur. The lava that erupts from volcanoes is partly magma. Deep underground, the rocks and water absorb the heat from this magma. The temperature of the rocks and water get hotter and hotter as you go deeper underground.

    People around the world use geothermal energy to heat their homes and to produce electricity by digging deep wells and pumping the heated underground water or steam to the surface. Or, we can make use of the stable temperatures near the surface of the earth to heat and cool buildings. (See Uses of Geothermal Energy below.)

    WHERE IS GEOTHERMAL ENERGY FOUND ?

    Most geothermal reservoirs are deep underground with no visible clues showing above ground.

    Image of a map of the world titled Ring of Fire. The ring of fire goes around the edges of the Pacific. The map shows that volcanc activity occurs around the Pacific rim.Geothermal energy can sometimes find its way to the surface in the form of:

        • volcanoes and fumaroles (holes where volcanic gases are released)
        • hot springs and
        • geysers.

    The most active geothermal resources are usually found along major plate boundaries where earthquakes and volcanoes are concentrated. Most of the geothermal activity in the world occurs in an area called the Ring of Fire. This area rims the Pacific Ocean.

    When magma comes close to the surface it heats ground water found trapped in porous rock or water running along fractured rock surfaces and faults. Such hydrothermal resources have two common ingredients: water (hydro) and heat (thermal). Naturally occurring large areas of hydrothermal resources are called geothermal reservoirs. Geologists use different methods to look for geothermal reservoirs. Drilling a well and testing the temperature deep underground is the only way to be sure a geothermal reservoir really exists.

    Most of the geothermal reservoirs in the United States are located in the western states, Alaska, and Hawaii. California is the state that generates the most electricity from geothermal energy. The Geysers dry steam reservoir in northern California is the largest known dry steam field in the world. The field has been producing electricity since 1960.

    USES OF GEOTHERMAL ENERGY

    Some applications of geothermal energy use the earth’s temperatures near the surface, while others require drilling miles into the earth. The three main uses of geothermal energy are:

    Image of a geothermal power plant. The Power Plant gets steam from a production well. The well gets steam from a geothermal reservoir. The used steam goes to an injection well that reinjects the fluid into the geothermal reservoir. 1) Direct Use and District Heating Systems which use hot water from springs or reservoirs near the surface.
    2) Electricity generation in a power plant requires water or steam at very high temperature (300 to 700 degrees Fahrenheit). Geothermal power plants are generally built where geothermal reservoirs are located within a mile or two of the surface.
    3) Geothermal heat pumps use stable ground or water temperatures near the earth’s surface to control building temperatures above ground.

    DIRECT USE OF GEOTHERMAL ENERGY

    The direct use of hot water as an energy source has been happening since ancient times. The Romans, Chinese, and Native Americans used hot mineral springs for bathing, cooking and heating. Today, many hot springs are still used for bathing, and many people believe the hot, mineral-rich waters have natural healing powers.

    After bathing, the most common direct use of geothermal energy is for heating buildings through district heating systems. Hot water near the earth’s surface can be piped directly into buildings and industries for heat. A district heating system provides heat for 95 percent of the buildings in Reykjavik, Iceland. Examples of other direct uses include: growing crops, and drying lumber, fruits, and vegetables.

    GEOTHERMAL POWER PLANTS

    Geothermal power plants use hydrothermal resources which have two common ingredients: water (hydro) and heat (thermal). Geothermal plants require high temperature (300 to 700 degrees Fahrenheit) hydrothermal resources that may come from either dry steam wells or hot water wells. We can use these resources by drilling wells into the earth and piping the steam or hot water to the surface. Geothermal wells are one to two miles deep.

    The United States generates more geothermal electricity than any other country but the amount of electricity it produces is less than 1 percent of electricity produced in United States. Only four states have geothermal power plants:

    • California – has 33 geothermal power plants that produce almost 90 percent of the nation’s geothermal electricity.
    • Nevada – has 15 geothermal power plants.
    • Hawaii and Utah – each have one geothermal plant

    There are three basic types of geothermal power plants:

    • Dry steam plants – use steam piped directly from a geothermal reservoir to turn the generator turbines. The first geothermal power plant was built in 1904 in Tuscany, Italy at a place where natural steam was erupting from the earth.
    • Flash steam plants – take high-pressure hot water from deep inside the earth and convert it to steam to drive the generator turbines. When the steam cools, it condenses to water and is injected back into the ground to be used over and over again. Most geothermal power plants are flash plants.
    • Binary power plants – transfer the heat from geothermal hot water to another liquid. The heat causes the second liquid to turn to steam which is used to drive a generator turbine.

    GEOTHERMAL HEAT PUMPS

    While temperatures above ground change a lot from day to day and season to season, temperatures in the upper 10 feet of the Earth’s surface hold nearly constant between 50 and 60 degrees Fahrenheit. For most areas, this means that soil temperatures are usually warmer than the air in winter and cooler than the air in summer. Geothermal heat pumps use the Earth’s constant temperatures to heat and cool buildings. They transfer heat from the ground (or water) into buildings in winter and reverse the process in the summer.

    According to the U.S. Environmental Protection Agency (EPA), geothermal heat pumps are the most energy-efficient, environmentally clean, and cost-effective systems for temperature control. Although, most homes still use traditional furnaces and air conditioners, geothermal heat pumps are becoming more popular. In recent years, the U.S. Department of Energy along with the EPA have partnered with industry to promote the use of geothermal heat pumps.

    GEOTHERMAL ENERGY AND THE ENVIRONMENT

    The environmental impact of geothermal energy depends on how it is being used.

    • Direct use and heating applications have almost no negative impact on the environment.
    • Geothermal power plants do not burn fuel to generate electricity, so their emission levels are very low. They release about 1 to 3 percent of the carbon dioxide emissions of a fossil fuel plant. Geothermal plants use scrubber systems to clean the air of hydrogen sulfide that is naturally found in the steam and hot water. Geothermal plants emit 97 percent less acid rain – causing sulfur compounds than are emitted by fossil fuel plants. After the steam and water from a geothermal reservoir have been used, they are injected back into the earth.
    • Geothermal features in national parks, such as geysers and fumaroles in Yellowstone National Park, are protected by law, to prevent the land from being disturbed.

    SOURCE:http://www.eia.doe.gov

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