Cogeneration, CHP

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Cogeneration, CHP As a Future Power Heat
Presented By P. S. Jalkote, EA-0366 Manager (
Operations EMC ) Reliance Energy Ltd. DTPS,
Dahanu
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Contents

• Introduction.
• What is Cogeneration (CHP) ?
• Why Cogeneration ?
• Cogeneration Principle.
• Cogeneration Technologies.
• Application of Cogeneration.
• Economics of Cogeneration.
• Usefulness of Cogeneration Technology.
• Policies.
• Summary.

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Introduction

• YesI, you, society, organization, state,
  nation and world need development.
• Not only development but a Sustainable
  development.
• Sustainable development benefits social,
  economic, technological, and environmental.
• Power (electricity) and Heat (i.e.CHP) plays a
  major role for development.
• Yes Cogeneration, Combined Heat and Power (CHP)
  can fulfill it for long way.

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What is Cogeneration ?

• Cogeneration the simultaneous production of
  heat and power, with a view to
  the practical application of both products.
• A way of local energy production.
• Used instead of separate production of heat and
  electricity.
• Heat is main product, electricity by-product or
  alternate.
• Uses heat that is lost otherwise.
• Way to use energy more efficiently.
• Different areas of application.
• Different technologies.

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Why Cogeneration ?

• Improve energy efficiency.
• Reduce use of fossil fuel.
• Reduce emission of CO2.
• Also,
• Reduce cost of energy.
• If heat fits demand, the cheapest way of
  electricity production.
• Improve security of supply.
• Use of organic waste as fuel.
• Position on energy market.

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Why Cogeneration ?

• Conventional power generation, on average, is
  only 35 efficient.
• Up to 65 of the energy potential is released as
  waste heat.
• More recent combined cycle generation can
  improve this to 55.
• In conventional electricity generation, further
  losses of around 5-10 are associated with
  the transmission and distribution of electricity.
• Through the utilization of the heat, the
  efficiency of cogeneration plant can reach 90
  or more.
• Cogeneration therefore offers energy savings
  ranging between 15-40.

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Separate production of Electricity Heat
Cogeneration
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Energy Efficiency (I)
Energy Efficiency (II)
Energy Efficiency (III)
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Cogeneration Principle

• When steam or gas expands through a turbine,
  nearly 60 to 70 of the input energy escapes
  with the exhaust steam or gas.
• This energy in the exhaust steam or gas is
  utilized for meeting the process heat
  requirements, the efficiency of utilization of
  the fuel increases.
• Such an application, where the electrical power
  and process heat requirements are met from the
  fuel, is termed as Cogeneration.
• Since, most of the industries need both heat and
  electrical energy, cogeneration can be a sensible
  investment for industries.
• It is also known as Combined Heat and Power
  (CHP) and Total Energy System.

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Classification of Cogeneration Systems

• There are two main types of cogeneration concepts
  
• Topping Cycle plants
• Bottoming Cycle plants

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Topping Cycle

• A topping cycle plant generates electricity or
  mechanical power first
• The four types of topping cycle cogeneration
  systems are
• A gas turbine or diesel engine producing
  electrical or mechanical power followed by a heat
  recovery boiler to create steam to drive a
  secondary steam turbine. This is called a
  combined-cycle topping system.

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Topping Cycle

• 2) The second type of system burns fuel (any
  type) to produce high-pressure steam that then
  passes through a steam turbine to produce power
  with the exhaust provides low-pressure process
  steam. This is a steam-turbine topping system.
• 3) A third type employs hot water from an
  engine jacket cooling system flowing to a heat
  recovery boiler, where it is converted to process
  steam and hot water for space heating
• 4) The fourth type is a gas-turbine topping
  system. A natural gas turbine drives a generator.
  The exhaust gas goes to a heat recovery boiler
  that makes process steam and process heat.

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Bottoming Cycle

• A bottoming cycle plant generates heat first.
• These plants are much less common than topping
• cycle plants.
• These plants exist in heavy industries such as
  glass or
• metal manufacturing where very high temperature
  
• furnaces are used.
• The waste gases coming out of the furnace is
  utilized in a boiler to generate steam, which
  drives the turbine to produce electricity.

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Cogeneration Technologies

• Backpressure Technology.
• Extraction Condensing Technology.
• Gas Turbine Heat Recovery Boiler Technology.
• Combined Cycle Technology.
• Reciprocating Engine Technology.
• Micro-turbines.
• Fuel cells.
• Stirling engines.

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Microturbine

• Nowadays there are microturbines as small as 25
  kW.
• In general, microturbines can generate anywhere
  from 25 kW to 200 kW of electricity.
• Microturbines are small high-speed generator
  power plants that include the turbine,
  compressor, generator, all of which are on a
  single shaft.
• As well as the power electronics to deliver the
  power to the grid.
• Moving part, use air bearings and do not need
  lubricating oil.
• They are primarily fuelled with natural gas, but
  they can also operate with diesel, gasoline or
  other
• similar high-energy fossil fuels. Research is
  ongoing on using biogas.

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Microturbine
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Microturbine
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Fuel cells

• Fuel cells convert the chemical energy of
  hydrogen and oxygen directly into electricity
  without combustion and mechanical work such as in
  turbines or engines.
• In fuel cells, the fuel and oxidant (air) are
  continuously fed to the cell.
• All fuel cells are based on the oxidation of
  hydrogen.
• The hydrogen used as fuel can be derived from a
  variety of sources, including natural gas,
  propane, coal and renewable such as biomass, or,
  through electrolysis, wind and solar energy.
• A typical single cell delivers up to 1 volt. In
  order to get sufficient power a fuel cell stack
  is made of several single cells connected in
  series.

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Fuel cells
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Fuel cells
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Stirling engines

• The Stirling engine is an external combustion
  device and therefore differs
• substantially from conventional combustion
  plant where the fuel burns inside the machine.
• Heat is supplied to the Stirling engine by an
  external source, such as burning gas, and this
  makes a working fluid, e.g. helium, expand and
  cause one of the two pistons to move inside a
  cylinder. This is known as the working piston.
• A second piston, known as a displacer, then
  transfers the gas to a cool zone where it is
  recompressed by the working piston. The displacer
  then transfers the compressed gas or air to the
  hot region and the cycle continues.
• The Stirling engine has fewer moving parts than
  conventional engines, and no valves, tappets,
  fuel injectors or spark ignition systems. It is
  therefore quieter than normal engines

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Stirling engines
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Heat-to-Power Ratio

• Most important technical parameter influencing
  the selection of the type of cogeneration system.
• The heat-to-power ratio of a facility should
  match with the characteristics of the
  cogeneration system to be installed.
• It is defined as the ratio of thermal energy to
  electricity required by the energy consuming
  facility.
• It can be expressed in different units such as
  Btu/kWh, kcal/kWh, lb./hr/kW.

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Heat-to-Power Ratio
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Advantages Disadvantages
Advantages Disadvantages
Steam Turbines High overall efficiency Any type of fuel may be used Heat to power ratios can be varied through flexible operation Ability to meet more than one site heat grade requirement Wide range of sizes available Long working life. High heat power ratios High cost Slow start-up.
Gas Turbines High reliability which permits - long-term unattended operation High grade heat available Constant high speed enabling - close frequency Control of electrical output High powerweight ratio No cooling water required Relatively low investment cost per kWe electrical output Wide fuel range capability (diesel, LPG, naphtha, associated gas, landfill sewage) Multi fuel capability Low emissions. Limited number of unit sizes within the Output range Lower mechanical efficiency than Reciprocating engines If gas fired, requires high-pressure supply or in-house boosters High noise levels (of high frequency can be easily alternated) Poor efficiency at low loading (but they can operate continuously at low loads) Can operate on premium fuels but need to be clean of dry
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Advantages Disadvantages
Advantages Disadvantages
Reciprocating Engines High power efficiency, achievable over a wide load range Relatively low investment cost per kWe electrical output Wide range of unit sizes from 3 kWe (there are 2,000 3 kWe installations in Germany) upward Part-load operation flexibility from 30 to 100 with high efficiency Can be used in island mode (all ships do this) good load following capability Fast start-up time of 15 second to full load (gas turbine needs 0.5 2 hours) Real multi-fuel capability, can also use HFO as fuel Can be overhaul on site with normal operators Low investment cost in small sizes Can operate with low-pressure gas (down to 1 bar Must be cooled, even if the heat recovered is not reusable Low powerweight ratio and out-of balance Forces requiring substantial foundations High levels of low frequency noise High maintenance costs.
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Advantages Disadvantages
Advantages Disadvantages
Stirling engines Technical advantages Much experience in high power range Less moving parts with low friction No internal burner chamber High theoretical efficiency Suitable for mass production. Advantages for micro-cogeneration No extra thermal-boiler necessary Electricity production independent from heat production Very low emissions Easy to control Can be built as an interchangeable unit. Little experience in low power range Poor shaft efficiency by the existing machines (350 800 Watt shaft power) Better efficiency at 3,000 Watt shaft power First machines have been/are very expensive.
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Application of Cogeneration
Scale of application Large scale small
scale. Heat usage Special process.
Technology Backpressure, Gas turbine, Combined
cycle, gas engine. User One user more
users. Ownership User cooperation.
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Application of Cogeneration

• Industrial
• Pharmaceuticals fine chemicals
• Paper and board manufacture
• Brewing, distilling malting
• Ceramics
• Brick
• Cement
• Food processing
• Textile processing
• Minerals processing
• Oil Refineries
• Iron and Steel
• Motor industry
• Horticulture and glasshouses
• Timber processing

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Application of Cogeneration

• Buildings
• District heating.
• Hotels.
• Hospitals.
• Leisure centres swimming pools.
• College campuses schools.
• Airports.
• Prisons, police stations, barracks etc.
• Supermarkets and large stores.
• Office buildings.
• Individual Houses.

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Application of Cogeneration

• Renewable Energy
• Sewage treatment works
• Poultry and other farm sites
• Short rotation coppice woodland
• Energy crops
• Agro-wastes (ex bio gas)
• Energy from waste
• Gasified Municipal Solid Waste
• Municipal incinerators
• Landfill sites
• Hospital waste incinerators

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Application of Cogeneration
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Application of Cogeneration
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Application of Cogeneration
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Economic Value of Cogeneration
Depends very much on tariff system. Heat -
avoided cost of separate heat production.
Electricity 1) Less purchase (kWh). 2) Sale of
surplus electricity. 3) Peak sharing. Carbon
credits (future).
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Energy Flows
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Money Flows
Rs.
Rs.
Rs.
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Economics
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Usefulness of Cogeneration Technologies

• To reduce power and other energy costs.
• To improve productivity and reduce costs of
  production through reliable uninterrupted
  availability of quality power from Cogeneration
  plant.
• Cogeneration system helps to locate
  manufacturing facility in remote low cost areas.
• Improves energy efficiency, and reduces CO2
  emissions therefore it supports sustainable
  development initiatives.
• The system collects carbon credits which can be
  traded to earn revenue.
• Due to uninterrupted power supply it improves
  working conditions of employees raising their
  motivation. This indirectly benefits in higher
  and better quality production.

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Usefulness of Cogeneration Technologies

• Cogeneration System saves water consumption
  water costs.
• Improves brand image and social standing.
• Cogeneration is the most efficient way of
  generating electricity, heat and cooling from a
  given amount of fuel. It saves between 15-40 of
  energy when compared with the separate production
  of electricity and heat.
• Cogeneration helps reduce CO2 emissions
  significantly. It also reduces investments into
  electricity transmission capacity, avoids
  transmission losses, and ensures security of high
  quality power supply.
• A number of different fuels and proven, reliable
  technologies can be used.
• A concurrent need for heat, electricity and
  possibly cooling indicates suitable sites for
  cogeneration.

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Usefulness of Cogeneration Technologies

• The initial investment in cogeneration projects
  can be relatively high but payback periods
  between 3-5 years might be expected.
• The payback period and profitability of
  cogeneration schemes depends crucially on the
  difference between the fuel price and the sales
  price for electricity.
• Global environmental concerns, ongoing
  liberalization of many energy markets, and
  projected energy demand growth in developing
  countries are likely to improve market conditions
  for cogeneration in the near future.

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Policies in support of Cogeneration

• In India, power development is the joint
  responsibility of the Central and State
  government.
• In fact, Section 44 (1) of E(S) Act 1948 bars
  any licensee or any other person other than the
  government or a government corporation from
  setting up a generating station without the
  consent of the State Electricity Board (SEB)
  concerned.
• And Section 44 (2A) requires the SEB to consult
  the Central Electricity Authority (CEA) before
  issuing a consent for capacities more than 25 MW.
  In India, cogeneration is synonymous with captive
  generation.
• Thus there was a need to open an alternative
  route other than private generating companies,
  where the industries themselves will be
  interested in meeting their own power demand by
  pooling resources together. Captive/cogeneration
  power plants offer such an alternative.

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Summary

• Cogeneration is proven technology.
• Cogeneration helps for sustainable development.
• Cogeneration improves energy efficiency..
• .if heat is used in a proper way.
• Otherwise it is just a bad way of electricity
  production.
• Scale is not a limit for cogeneration.
• Right dimensioning is crucial for economic
  application.
• Economic performance will increase because of
  environmental policy.

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THANK YOU
for your attention
Cogeneration, the path to profit and
Sustainable development
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Policies in support of Cogeneration

• Central Government Policy Initiatives
• The Center asked all state Governments in
  October1995 for the first time to create an
  institutional mechanism allowing
  captive/cogeneration power plants an easy and
  automatic entry through quick clearance, rational
  tariff for purchase of surplus power by the grid,
  and third party access for direct sale of power
  to other industrial units. The Center notified a
  resolution on "Promotion of Cogeneration Power
  Plants" on 6 November1996. The basic features
  are
• It recognized the importance of cogeneration and
  emphasized its development with the combined
  objectives of promoting better utilization of
  precious energy resources in industrial
  activities and creation of additional power
  generation capacity in the system.
• Captive power plants of any other persons
  (including juristic persons and excepting
  generating companies) are not subject to the
  provisions of Section 29(2) of the E(S) Act.

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Policies in support of Cogeneration

• It recognized that industry in general and a
  process industry in particular needs energy in
  more than one form, and if the energy
  requirements and supply to the industrial units
  are carefully planned overall efficiency of a
  very high order is possible to achieve.
• Emphasis on institutional mechanisms highlighting
  the issues involved.
• Two basic cogeneration cycles have been
  identified
• Topping Cycle - Any facility that uses fuel input
  for power generation and heat for other
  industrial activities. In any facility with a
  supplementary firing facility, it would be
  required that the useful heat to be utilized in
  the industrial activities, is more than the heat
  to be supplied to the system through
  supplementary firing by at least 20.
• Bottoming Cycle - Any facility that uses waste
  industrial heat for power generation by
  supplementing heat from any fossil fuel.
• Qualifying RequirementsA facility may qualify to
  be termed as a cogeneration facility if it
  satisfies certain operating and efficiency
  standards.

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Policies in support of Cogeneration

• Qualifying Requirements for Topping Cycle
• It depends on the type of fuel used as the
  overall efficiency levels likely to be achieved
  for power generation varies with the choice of
  fuel. For coal and refinery bottoms, the sum of
  useful power output and one half the useful
  thermal output should be greater than 45 of the
  facility's energy consumption. For liquid fuel,
  the sum of useful power output and useful thermal
  output should be greater than 65 of the
  facility's energy consumption.
• The Facility must be able to supply at least 5 MW
  of power for at least 250 days in a year.
• Qualifying Requirements for Bottoming CycleThe
  total useful power output in any calendar year
  must not be less than 50 of the total heat input
  through supplementary firing.
• Benefits of Cogeneration Systems
• High efficiency - by utilizing the same fuel to
  provide heat and electricity, and thereby reduce
  fuel consumption, fuel cost, electric utility
  bills, and provide economic competitive
  advantages through a maximized return on
  investment capital

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Policies in support of Cogeneration

• More useful energy due to recovery of otherwise
  wasted heat and energy conservation
• More environment friendly because of efficient
  fuel use and reduced air emissions (GHG, sulfur
  dioxide, nitrogen oxides, particulate) and
  reduced thermal pollution
• A reliable source of power and process steam or
  heat. This is particularly important in regions
  prone to frequent disruptions in electricity
  supply
• Onsite electricity generation can eliminate
  losses (8-10) in the transmission and
  distribution systems and
• Low gestation period.
• Foreign Investment Policy
• Foreign investors can enter into a joint venture
  with an Indian partner for financial and/or
  technical collaboration and also for setting up
  renewable energy-based power generation projects.
  
• Liberalized foreign investment approval regime to
  facilitate foreign investment and transfer of
  technology through joint ventures.
• The proposals for up to 74 foreign equity
  participation in a joint venture qualify for
  automatic approval.

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Policies in support of Cogeneration

• 100 foreign investment as equity is permissible
  with the approval of the Foreign Investment
  Promotion Board (FIPB).
• Various Chambers of Commerce and Industry
  Associations in India can be approached for
  providing guidance to investors in finding
  appropriate partners.
• Foreign investors can also set up a liaison
  office in India.
• Government of India is also encouraging foreign
  investors to set up renewable energy based power
  generation projects on Build Own and Operate
  (BOO) basis.
• Policy Initiatives at State Government Level
• For encouraging investment by the private and
  public sector companies in power generation
  through renewable energy, a set of guidelines
  have been issued by the Ministry of
  Non-Conventional Energy Sources for consideration
  by the States.
• In addition, some States are providing
  concession/ exemption in State Sales Tax and
  Octroi, etc.
• Maharashtra allows projects on a co-operative
  basis also and the Maharashtra State Electricity
  Board provides equity participation.
• Karnataka extends a subsidy of Rs 2.5 million/MW.

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Success Story

• Godavari Sugars
• The Godavari Sugar Mills Ltd, Sameerwadi,
  Karnataka, has a present crushing capacity of
  8,500 TCD. The management conceived the idea of
  setting up a 24 MW high-efficiency cogeneration
  plant in 1997.
• Reliance Energy, Noida was the EPC contractor
  for the cogeneration project, and Desein (P) Ltd
  was the project consultant and also the
  Operations Maintenance (OM) contractor for the
  project for five years. Such an EPC/OM contract
  for a cogeneration project was undertaken for the
  first time in India. The 24 MW cogeneration plant
  was synchronized with the Karnataka Power
  Transmission Corporation (KPTCL) grid through a
  sub-station at Mahalingpur on 16 March 2002.
  Commercial operation commenced from April 9,
  2002.
• There is a captive consumption of 6 MW during
  the season and 3 MW in the off-season and the
  balance is exported to the KPTCL. Apart from
  power generation, the cogeneration plant also
  meets part of the steam requirements of the sugar
  factory and distillery.
• The total project cost of Rs 108 crore was met
  with loans (Rs 74 crore) from lDBI, Andhra Bank
  and the State Bank of India (SBI), while the
  equity was met (Rs 34 crore) with the USAID
  GEP-ABC grant of Rs 4.2 crore.

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Success Story

• Godavari Sugars
• The plant is fully automatic with
  state-of-the-art technology including triple
  modular redundancy in all controls. The plant
  also incorporates the latest version of
  distributed control systems (DCS).
• Special Features of the Cogeneration Plant
• The highest capacity bagasse -fired boiler in
  India.
• Turnkey EPC/OM contract for the first time in
  India.
• Fully automatic plant with logic redundancy for
  all criticial controls.
• Mechanized bagasse stacking.
• Modern fire-fighting system.