Waste generation trends in India

Any organic waste from urban and rural areas and industries is a resource due to its ability to get degraded resulting in energy generation.Waste can be processed through any of the following technological options, which can be categorized into thermal or biological conversion resulting in energy generation. The technologies for energy generation from solid wastes are multiple.

?         Sanitary landfill

?         Incineration

?         Anaerobic digestion

?         Pelletisation/briquetting

For liquid wastes, such as sewage and effluents from industries, anaerobic digestion is the suitable technological option for recovery of energy.

The process of anaerobic digestion and landfill results in biogas production from organic waste. Biogas is a mixture of methane and carbon dioxide. Methane?discovered in 1776 by Alessandro Volta, an Italian physicist?is highly inflammable. The calorific value of methane is 13157.89 KCal/kg. This process of methane generation, ie, biomethanation, is an effective tool to dig out the wealth from waste with high moisture content. But for dry waste, the best technique is the production of refuse derived fuel pellets through pelletization that can be burned directly for thermal application or power generation.

There is a huge energy generation potential associated with the solid and liquid wastes.

A. Waste generation trends in India

Year	Per capita waste generation (g/day)	Total urban municipal waste generation (MT/ yr)
1971	375	14.9
1981	430	25.1
1991	460	43.5
1997	490	48.5
2025	700	Double the amt. of 1997

B. Potential of power generation

Urban and municipal wastes                                           1000 MW

Industrial wastes                                                                 700 MW

 (dairy, distillery, tannery, pulp and paper,

and food processing industry)

Total                                                                                      1700 MW

Related websites

www.ows.be/dranco.htm

www.kompogas.ch/en.The_kompogas_process/the_ kompogas_process.html

www.undp.org.in/programme/GEF/dec%2002/deci2/article-3.htm

http://static.teriin.org/case/team.htm

http://www.indiawteplan.com/

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Geothermal energy is the natural heat of the earth

Geothermal energy is the natural heat of the earth. Earth's interior heat originated from its fiery consolidation of dust and gas over 4 billion years ago. It is continually regenerated by the decay of radioactive elements, that occur in all rocks.

From the surface down through the crust, the normal temperature gradient - the increase of temperature with the increase of depth - in the Earth's crust is 17 °C -- 30 °C per kilometer of depth (50 °F -- 87 °F per mile).

Below the crust is the mantle, made of highly viscous, partially molten rocks with temperatures between 650 °C -- 1250 °C (1200 °F -- 2280 °F). At the Earth's core, which consists of a liquid outer core and a solid inner core, temperatures vary from 4000 °C -- 7000 °C (7200 °F-- 12600 °F).

Major geothermal fields are situated in circum-pacific margins, rift zones of East Africa, North Africa, Mediterranean basin of Europe, across Asia to Pacific (Figure 1).
Figure 1:



Geothermal reserves up to depths of 10 km are estimated at 403X106 Quads. The world average geothermal heat flow is 0.06 W/m2

There are four major types of Geothermal energy resources.

Hydrothermal
Geopressurised brines
Hot dry rocks
Magma


Currently, hydrothermal energy is being commercially used for electricity generation and for meeting thermal energy requirements. In 1997, The world's geothermal electricity generation capacity was 8000 MW and another 12000 MW for thermal applications.

Italy, New Zealand, USA, Japan, Mexico, Philippines, Indonesia are some of the countries which are using geothermal energy for electricity generation and thermal applications. Exploration of geothermal fields needs knowledge of geology, geochemistry, seismology, hydrology and reservoir engineering.

In India, exploration and study of geothermal fields started in 1970. The GSI (Geological Survey of India) has identified 350 geothermal energy locations in the country. The most promising of these is in Puga valley of Ladakh. The estimated potential for geothermal energy in India is about 10000 MW.

There are seven geothermal provinces in India : the Himalayas, Sohana, West coast, Cambay, Son-Narmada-Tapi (SONATA), Godavari, and Mahanadi.
The important sites being explored in India are shown in the map of India (Figure 2) .

Figure 2 :



Technology for electricity generation

There are two types of the plants.

1. Flash steam plants
When the geothermal energy is available at 150 °C and above temperature, the fluids can be used directly to generate electricity. In some cases, direct steam is available from the geothermal reservoir; otherwise the steam is separated and turbines are used for power generation.

2. Binary plant
These plants are used when geothermal temperature is between 100 °C and 150 °C. The fluid is extracted and circulated through a heat exchanger where the heat is transferred to the low boiling point organic liquid. This gets converted into high pressure vapour, which drives organic fluid turbines (Figure 3b).

Figure 3 (a) :

Figure 3 (b) :



Source - http://www.worldenergy.org/wec-geis/publications/reports/ser/geo/geo.asp

Direct use of geothermal energy si also possible as shown in the Figure 4.

These systems are useful for heating of houses and living spaces like offices, commercial complexes etc.

Figure 4 :


Source - http://www.worldenergy.org/wec-geis/publications/reports/ser/geo/geo.asp

Indian organisations working in geothermal energy:

Central Electricity Authority
Geological Survey of India
Indian Institute of Technology, Mumbai
Regional Research Laboratory, Jammu
National Geophysical Research Institute, Hyderabad
Oil and Natural Gas Corporation, Dehradun

Ongoing Projects in India:

Magneto-telluric investigations in Tattapani geothermal area in Madhya Pradesh
Magneto-telluric investigations in Puga geothermal area in Ladakh region, Jammu & Kashmir

Achievements:

Geothermal Atlas of India, prepared by the Geological Survey of India(GSI) gives information/data for more than 300 geothermal potential sites. This Atlas is being updated by GSI with the support from MNES.
Applications of geothermal energy for small-scale power generation and thermal applications are being explored.

Potential Applications:
Power generation
Cooking
Space heating
Use in greenhouse cultivation
Crop drying

Related link

hhttp://www.tifac.org.in
http://www.tifac.org.in/offer/tlbo/rep/TMS153.htm#method
http://www1.eere.energy.gov/geothermal/geothermal_basics.html
http://mnes.nic.in/business%20oppertunity/retnt.htm
http://www.worldenergy.org/wec-geis/publications/reports/ser/geo/geo.asp
http://www.geos.iitb.ac.in
http://www.gsi.gov.in
http://geothermal.marin.org/
http://www.ngri.org.in
http://www.iea.org
http://iga.igg.cnr.it/index.php

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biomass has always been an important energy source

Biomass has been one of the main energy sources for the mankind ever since the dawn of civilisation, although its importance dwindled after the expansion in use of oil and coal in the late 19th century. There has been a resurgence of interest in the recent years in biomass energy in many countries considering the benefits it offers. It is renewable, widely available, and carbon-neutral and has the potential to provide significant productive employment in the rural areas. Biomass is also capable of providing firm energy. Estimates have indicated that 15% - 50% of the world?s primary energy use could come from biomass by the year 2050. Currently, about 11% of the world?s primary energy is estimated to be met with biomass.

For India, biomass has always been an important energy source. Although the energy scenario in India today indicates a growing dependence on the conventional forms of energy, about 32% of the total primary energy use in the country is still derived from biomass and more than 70% of the country?s population depends upon it for its energy needs.

India produces a huge quantity of biomass material in its agricultural, agro-industrial and forestry operations. According to some estimates, over 500 million tonnes of agricultural and agro-industrial residue alone is generated every year. This quantity, in terms of heat content, is equivalent to about 175 million tonnes of oil. A portion of these materials is used for fodder and fuel in the rural economy. However, studies have indicated that at least 150-200 million tonnes of this biomass material does not find much productive use, and can be made available for alternative uses at an economical cost. These materials include a variety of husks and straws. This quantity of biomass is sufficient to generate 15 000-25 000 MW of electrical power at typically prevalent plant

Biomass Gasification

Biomass gasification is the process through which solid biomass material is subjected to partial combustion in the presence of a limited supply of air. In what is known as a gasifier, solid fuel is convertedm by a series of thermo-chemical processes like drying, pyrolysis, oxidation, and reduction to a gaseous fuel called producer gas. The ultimate product is a combustible gas mixture known as ?producer gas?. If atmospheric air is used as the gasification agent, which is the normal practice, the producer gas consists mainly of carbon monoxide, hydrogen, and nitrogen. A typical composition of the gas obtained from wood gasification, on volumetric basis, is as follows:

Carbon monoxide 18 ? 22%

Hydrogen 13 ? 19%

Methane 1 ? 5%

Heavier hydrocarbons 0.2 ? 0.4%

Heavier hydrocarbons 9 ? 12%

Water vapour 4%

The calorific value of this gas is about 1000 ? 1200 kcal.Nm3.

Biomass gasifier based systems

The major applications of a producer gas produced from a biomass gasifier are as follows .

i) Mechanical shaft power applications, i.e., water pumping for irrigation/drinking and grinding, where the gas is used as fuel for internalcombustion engine running on dual fuel or 100% producer gas mode.

ii) Direct heat applications where it is burnt directly in a boiler, furnace or kiln, burner for institutional cooking, etc., to provide heat.

iii) Electricity generation through shaft power application viz., (engine coupled to an alternator/generator set).
From http://www.indiaenergyportal.org/subthemes_link.php?text=biomass&themeid=5

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Hydro power currently suffices one fifth of the global electricity supply

The word hydro comes from a Greek word meaning water. The energy from water has been harnessed to produce electricity since long. It is the first renewable energy source to be tapped essentially to produce electricity.

Hydro power currently suffices one fifth of the global electricity supply, also improving the electrical system reliability and stability throughout the world. It also substantially avoids the green house gas emissions, thus complimenting the measures taken towards the climate change issues.

Hydro projects below a specified capacity are known as small hydro. The definition of small hydro differs from country to country, depending on the resources available and the prevalent national perspective. The small hydro atlas shows that the largest of the projects (30 MW) is in US and Canada. Small hydro power has emerged as one of the least cost options of harnessing green energy amongst all the renewable energy technologies.

According to the power generated, small hydro power is classified into small, mini/micro and pico hydro. In India, it is being classified as follows.

Small hydro - 2 MW - 30 MW
Mini - 100 kW - 2 MW
Micro - 10 kW - 100 kW
Mico hydro - 1 kW - 10 kW

Projects with the range of 100 kW and above feed power into the grid. They are commercial by nature. Projects below 100 kW are mostly off grid options being harnessed for rural village electrification. They come under the social sector.


Hydro Power


The basics of power from water is the result of conversion of potential energy (the water body at a certain height which is known as the "Head") to kinetic energy (a flow which is known as "Discharge" down the pipe) which is transferred to the buckets in the turbine (mechanical energy). It is the prime mover for the generator (electrical energy) which produces electricity.

Essentially power from a small hydro potential site is derived from two parameters, head and discharge .

Where "head" is the vertical height from which the potential energy of water is converted into electricity after the fall and discharge is the flow rate of the water in the stream/river.

Power (kW) = H * Q * Y

Where
H = Head in m(meter)
Q = Discharge in m3/sec (cumecs) Y = Specific weight of water, being the product of mass and acceleration due to gravity (9.81 kN/m3).

An altimeter is used for head measurement and various methods are used for discharge measurement based on the site conditions. Limited civil works is carried out for the development of the site for small hydro power. To maintain the power quality controllers and electrical equipments is used.

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Wind resource in India

The sun?s energy falling on the earth produces large-scale motions of the atmosphere causing winds, which are also influenced by small scale flows caused by local conditions such as nature of terrain, buildings, water bodies, etc. Wind energy is extracted by turbines to convert the energy into electricity.

A small-scale and large-scale wind industry exists globally. The small-scale wind industry caters for urban settings where a wind farm is not feasible and also where there is a need for household electricity generation. The large-scale industry is directed towards contributing to countrywide energy supply.

Wind resource in India

The wind resource assessment in India estimates the total wind potential to be around 45 000 MW (mega watt). This potential is distributed mainly in the states of Tamil Nadu, Andhra Pradesh, Karnataka, Gujarat, Maharashtra, and Rajasthan. The technical potential that is based on the availability of infrastructure, for example the availability of grid, is estimated to be around 13 000 MW. In India, the wind resources fall in the low wind regime, the wind power density being in the range of 250 -450 W/m2. It may be noted that this potential estimation is based on certain assumptions. With ongoing resource assessment efforts, extension of grid, improvement in the wind turbine technology, and sophisticated techniques for the wind farm designing, the gross as well as the technical potential would increase in the future.

Status

Wind power has become one of the prominent power generation technology amongst the renewable energy technologies. By the end of 2005, the total wind power installed globally was about 59 084 MW, a growth of 24% over 2004. The leading countries in wind power installation are Germany (18 428 MW), Spain (10 027 MW), the USA (9 149 MW), India (4 430 MW) and Denmark (3 122 MW). India has overtaken Denmark and is the fourth largest wind market in the world.

Wind energy technology trends

Use of wind energy started long ago when it was used for grinding. The commercial use of wind energy for electrical power generation started in 1970s. Horizontal axis wind turbines are most commonly used for power generation, although some vertical axis wind turbine designs has been developed and tested. The vertical axis turbines have structural as well as aerodynamic limitations and, hence, are not commercially used. The wind power generation is simple conversion of kinetic energy in the wind into electrical energy. However, the mechanism to capture, transmit, and convert the energy into electrical energy involves several stages, components, and controls. The important components/controls of horizontal axis wind turbine are

Ÿ         rotor blades,

Ÿ         generator,

Ÿ         aerodynamic power regulation,

Ÿ         yaw mechanism, and

Ÿ         tower.

The wind turbine technology is being continuously improved worldwide resulting in improved performances, optimal land use, and better grid integration. The areas in which development work is being targeted are large size wind turbines, powerful and larger blades, improved power electronics, and taller towers.

Rotor blades

The rotor blade is the most critical component of the wind turbine. It captures the wind energy and transfers it to torque required to generate power. The aerodynamic design of the blade is important as it determines the energy capture potential. One indicator of effective blade design is the weight/swept area ratio. As the size of the wind turbine increases, the size of blade length increases proportionally which results in capturing more energy. These blades are of higher tensile strength and lower body mass. Commonly used materials for making the blades are composite materials like the glass fibre epoxy, carbon epoxy, fibre-reinforced plastic, etc.

Generator

The kinetic energy captured by the rotor blades is transferred to the generator through the transmission shaft. Wind machines with induction generators come with gear boxes.

Wind machines which have synchronous generators have no gear boxes since they could be designed for continuous variation according to the wind speed. These machines have an added advantage over induction machines because variable speed increases the energy capture. This increases the efficiency of the system on the whole by exactly matching the wind speed to the rotor speed of the generator. Variable speed machines grant flexibility and good power quality but are expensive because of the power electronics involved.

Aerodynamic power regulation

Out of the two basic concepts of aerodynamic controls, the stall and pitch mechanisms, the pitch control is predominantly used especially for the larger size wind turbines. Pitch regulation offers better control on the power regulation with independent pitching of the blades. The latest concept is active pitch or active stall.

Increasing number of larger wind turbines (1 MW and above) are being developed with an active stall control mechanism. At low wind speeds, the machines are usually programmed to pitch their blades much like a pitch-controlled machine. However, when the machine reaches its rated power and the generator is about to be overloaded, the machine will pitch its blades in the opposite direction. This is similar to normal stall power limitation, except that the whole blade can be rotated backwards (in the opposite direction as is the case with pitch control).

One of the advantages of active stall is that one can control the power output more accurately than with stall, so as to avoid overshooting the rated power of the machine at the beginning of a gust of wind. Another advantage is that the machine can be run almost exactly at rated power at all high wind speeds. In active pitch control, the blade pitch angle is continuously adjusted based on the measured parameters to generate the required power output. It has been established that active pitch regulation reduces the wind generator output fluctuations.

Tower

Two most common tower designs are lattice and tubular. Lattice tower is cheaper compared to the tubular tower and being usually a bolted structure is easier to transport. However, since lattice tower consists of many bolted connections, these connections need to be tightened and checked periodically, thereby increasing the operation and maintenance cost. By nature, tubular tower is stiffer than the lattice one. However, the tubular tower allows full internal access to the nacelle.

Larger turbine size

An important improvement in the wind turbine design has lead to increased size and performance. From machines of just 25 kW two decades ago, the commercial range sold today is typically from 600 - 2 500 kW. As such, the largest wind turbine capacity today is 5 MW. With the development of higher size turbines for a required capacity, lower number of turbines are required which has implication on the investment as well as O&M costs.

Off shore wind

As a result of lower resistance, the wind resource at the offshore locations is higher in terms of wind speed. Also, wind resources are uniform having lower variations and turbulence. The higher capacity wind turbines, which are being developed today, focus on the off shore applications. The related foundation technologies are also being developed for the erection of higher capacity wind turbines. In case of India, however, the development for offshore wind is yet to start.

Wind power in India

Wind turbines offered in India range from 250 kW to 2 MW capacities. As of 31 March 2006, the total installed capacity in the country was 5340 MW, which is 46% of the total capacity of renewable resources based power generation. There are 7 manufacturers of wind turbine generators in India.
from http://www.indiaenergyportal.org/subthemes_link.php?text=wind&themeid=3

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Energy Solutions

EnergySolutions, headquartered in Salt Lake City, Utah, is one of the world’s largest processors of low level waste (LLW), and is the largest nuclear waste company in the United States[citation needed]. It was founded by Steve Creamer in 2007 through the merger of four waste disposal companies : Envirocare, Scientech D&D, BNG America, and Duratek.

EnergySolutions has operations in over 40 states; and owns and operates a licensed landfill to dispose of radioactive waste approximately 60 miles west of Salt Lake City, UT in Tooele County, Utah. It also operates another disposal site in Barnwell County, South Carolina. The company possesses technology to convert waste into alternative material such as durable glass, and is contracted by the United States Department of Energy to assist in waste conversion efforts. The company holds the naming rights to EnergySolutions Arena.

On June 7, 2007, the company took over operational and management responsibilities of several Magnox atomic plants from British Nuclear Fuels plc in United Kingdom through the acquisition of the BNFL subsidiary - Reactor Sites Management Company (RMSC).[1][2]

Creation of EnergySolutions

Envirocare of Utah purchased the Connecticut-based Scientech D&D division in October 2005.[3] On February 2, 2006, Envirocare announced the $90 million purchase of BNG America a subsidiary of British Nuclear Fuels (BNFL) based in Virginia.[4] The merged company would change its name to EnergySolutions, with corporate headquarters based in Salt Lake City, Utah. On February 7, 2006, EnergySolutions announced it would buy Maryland-based Duratek, a publicly traded company, for $396 million in an all-cash deal.[5] The leveraged buyout was financed by banks led by Citigroup, effectively taking the company private.

After the acquisitions, EnergySolutions has 2,500 employees in 40 states with an annual revenue of $280 million.[6] Additionally, EnergySolutions owns two of the nation's three commercial low-level nuclear-waste repositories, although its primary competitor, Waste Control Specialists, hopes to build a fourth repository in Texas.
Envirocare

Envirocare (also called Envirocare of Utah, Inc.) was a company that disposed of Class A low level radioactive waste (LLRW) in an engineered landfill. It began operations in 1990 and was located in Clive, Utah.[7]

Envirocare was founded by Iranian immigrant Khosrow Semnani in 1988. Semnani served as president of the company until May 1997, when Envirocare's largest customer—the Department of Energy—requested that he step down in the wake of a bribery scandal.[8]

In mid-December 2004, Semnani sold Envirocare for an undisclosed sum. Steve Creamer became the company's new CEO. The deal was financed by private equity firms, led by Lindsay Goldberg & Bessemer of New York, Creamer Investments, and Peterson Partners both of Salt Lake City. Envirocare management promised to drop plans to bury hotter class B and C nuclear waste in Utah in deference to developing political opposition to the company, which was poised to ban the waste anyway.[9] Envirocare's management and ownership was retained as it made the acquisitions to become EnergySolutions.
Duratek

Based in Columbia, Maryland, Duratek was founded in 1983. In 1990, the company merged with General Technical Services (GTS); the resulting company was known as GTS Duratek.[10] That year, the company formed a joint venture with another firm — Chem-Nuclear Systems, Inc. — to build a commercial vitrification system.

In 1997, GTS Duratek acquired the Scientific Ecology Group (SEG). In 2000, the company purchased the nuclear services business arm of Waste Management Inc.[11] One year later, the company announced that it was dropping GTS from its name, and was once again known as Duratek.

Duratek was purchased by EnergySolutions at 25.7% premium over the February 7, 2006 stock price when the merger was announced.[5]
Energy Solutions

Since its inception, Energy Solutions has brought primarily domestic, Class A nuclear waste to Utah's west desert.

On June 7, 2007, the company announced the acquisition of the UK based BNFL subsidiary - Reactor Sites Management Company (RSMC).[1][2] The sale also included Magnox Electric Limited (MEL), a wholly owned subsidiary of RSMC, which holds the contracts and licences to operate ten nuclear reactor sites in the UK on behalf of the Nuclear Decommissioning Authority (NDA). Through the acquisition, the company took over operational and management responsibilities of several Magnox atomic plants from British Nuclear Fuels plc.

In 2009 it attempted to bring 20,000 tons of waste from Italy's shuttered nuclear power program through the ports of either Charleston, S.C., or New Orleans.[12] After processing in Tennessee, about 1,600 tons would be disposed of in Utah. The importation attempt was eventually abandoned.[13]

EnergySolutions has also sought at various times for the State of Utah’s permission to blend, or dilute, currently accepted Class A low-level radioactive waste with more radioactive Class B and Class C wastes until it just meets the Class A waste levels its license allows per container at its Clive disposal site.[14] Some estimate that this could increase Energy Solutions' Utah site current amount of 7,450 curies of radiation per annum (2010), to an additional 19,184 to 28,470 curies each year.[14] The Division of Radiation Control of Utah is currently considering this measure to allow Class B and Class C waste into Utah.[15] If allowed, this would make Utah, along with Texas, the only state in the nation to allow the importation of Class B and C radioactive wastes.[15]

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