A Customer Guide to Combined Heat and Power

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A Customer Guide to Combined Heat and Power A product of the Commercial Buildings Consortium emissions rates compared to separate heat and power systems

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Table of Contents Available Resources,www ESCenter org. What is Combined Heat Power 1 www PowerOnsite org,www GasAirConditioning com. Prime Movers 3, Reciprocating Engines 4 U S Department of Energy and FEMP. http www1 eere energy gov industry,Combustion Turbines 5 distributedenergy. http www1 eere energy gov femp technologies der,Micro Turbines 6 chp chpbasics html.
http www eea inc com chpdata,Steam Turbines 7,U S Environmental Protection Agency EPA. Fuel Cells 8 http www epa gov chp,Micro CHP 9,Waste Heat Recovery 10. Site vs Source 12,Environmental Benefits 13,Economics 15. Available Resources 18,Spark Spread What is Combined Heat Power. Avg Commercial Natural Gas Price Avg Commercial Retail Electricity Price. The self generation of power incorporating heat recovery is known. today by many names and acronyms,8 00 CCHP Combined Cooling Heating and Power.
6 00 Cogen Cogeneration,DER Distributed Energy Resources. DG Distributed Generation,IES Integrated Energy Systems. TES Total Energy Systems,Source US DOE Energy Information Administration. This customer guide will use the term Combined Heat and Power. Spark spread is one of the evaluations that should be considered in CHP to better reflect the importance of recovering the available. your CHP economics Spark spread is the gross margin of the CHP heat from the power generation process Regardless of name. plant of selling a unit of electricity having bought the fuel required to preference all refer to integrated technologies that produce. produce this power In this calculation it is important to have both electricity and simultaneously capture and put the heat normally. electric and gas prices in the same currency and must refer to the wasted in the central production of electricity to a productive use. same energy units All other costs operation and maintenance. capital and other financial costs must also be covered from the. spark spread for the facility to produce favorable economics The CHP system is located at or near your building and generates. electricity or mechanical power with the added benefit of recovering. the waste heat in the form of hot water steam or warm air This. high quality and very reliable power system provides a secure. energy source along with the ability to provide heating cooling or. de humidification of your facility as a byproduct of your electrical. The real key to an efficient,and economical CHP,system is having the need. for simultaneous use of,both electricity and heat,PAGE 16 PAGE 1.
CHP is not a single technology but an integrated energy system Economics. that can be modified depending upon the needs of the energy end. user These systems simply capture and utilize excess heat. generated during the production of electric power CHP systems Cost is an important factor when considering the purchase of any. offer economic environmental and reliability related advantages product including CHP However determining the cost of CHP. compared to power generation facilities that produce only electricity technology is often more complex than simply purchasing a piece of. Distributed power generation systems which are frequently located hardware at a published price In addition to equipment or capital. near thermal loads are particularly well suited for CHP applications cost there are labor and other expenses related to installing the. equipment The cost of electricity produced by the CHP system can. CHP efficiency seeks to capture the energy content of both also be estimated and compared to the price currently being paid for. electricity and usable heat and is the net electrical output plus the electricity from the power grid. net useful thermal output of the CHP system divided by the fuel. consumed in the production of electricity and heat While total CHP Equipment costs for CHP technologies are often quoted in terms of. efficiency provides a measure for capturing the energy content of their cost per kilowatt of electricity produced or kW Typically the. electricity and heat produced it does not adequately reflect the fact larger the system the better the economics. that electricity and heat have different qualities The quality and. value of electrical output is higher relative to heat output and is. evidenced by the fact that electricity can be transmitted over long Purchasing a system that matches your thermal need will offer the. distances and can be used for many purposes best economics With paybacks estimated to be 3 5 years. CHP Efficiencies,Conventional,Power Generation,Combined Heat Power. 5 MW Natural Gas,Combustion Turbine,Power Station,Power Station Fuel. 103 Efficiency 30,Electricity,31 Combined,Total Fuel CHP Fuel. 168 Losses Heat and 100, 13 When considering the adoption of a CHP technology many. System questions must be asked to determine which technology best fits the. Boiler 52 specific situation especially in terms of meeting the energy. Boiler Fuel, requirements at a cost that is acceptable The decision analysis.
65 should include an evaluation of the real time power and thermal. uses at your facility A cash flow analysis should be performed. Efficiency 80, along with this analysis to insure the real project economics. 49 Total Efficiency 83,PAGE 2 PAGE 15, Fuel cell systems have inherently low emissions profiles because the Prime Movers. primary power generation process does not involve combustion The. fuel processing subsystem does not require any emissions control. There are five types of prime movers for CHP systems. devices to meet current or projected regulations,Reciprocating Engines. While not considered a pollutant in the ordinary sense of directly. affecting health CO2 emissions do result from the use the fossil fuel Combustion Turbines. based CHP technologies The amount of CO2 emitted in any of the Microturbines. CHP technologies discussed above depends on the fuel carbon content Steam Turbines. and the system efficiency The fuel carbon content of natural gas is Fuel Cells. typically 34 lbs carbon MMBtu which is relatively low. Reciprocating Engine High fuel efficiency, Natural gas for CHP is emerging as the preferred fuel choice This is Lower Initial costs vs larger turbines. due to natural gas being widely available and competitively priced Best for variable load applications. More tolerant to high ambient conditions, versus other fuel sources Further public policy and the local green and high elevations.
market are causing businesses and institutions to re think gas CHP Lower fuel pressure requirement. Accept low BTU fuels,On line in less than 30 seconds. In addition to cost savings CHP technologies offer significantly lower Offer black start opportunity. emissions rates compared to separate heat and power systems The Combustion Turbines. primary pollutants from gas turbines are nitrogen oxides NOx carbon Well suited for CHP w large heat to ekW ratio. monoxide CO and volatile organic compounds VOCs Other High exhaust temperatures 480 C 900 F. Low weight minimal space requirement, pollutants such as sulfur oxides SOx and particulate matter PM are Very simple design. primarily dependent on the fuel used Similarly emissions of carbon Lower emissions capabilities. dioxide are also dependent on the fuel used Ideal for 24 7 operation. Accept high or low BTU fuels, Many gas turbines burning natural gas feature lean premixed burners Microturbines. also called dry low NOx burners 30 200 ekW sizes available. Lightweight small footprint, Microturbines have the potential for low emissions All microturbines. Multi fuel capability, operating on gaseous fuels feature lean premixed combustor Air cooled.
technology The primary pollutants from microturbines include NOx Ultra low emissions. CO and unburned hydrocarbons They also produce a negligible High reliability. Minimal scheduled maintenance, amount of SO2 Microturbines are designed to achieve low emissions Accepts various fuel sources. at full load and emissions are often higher when operating at part load. Fuel Cells,Grid independent operation,Electric load following. Multi megawatt capacity,Low pressure natural gas fuel. Low noise and vibration,Ultra low emissions,10 year cell stack life. PAGE 14 PAGE 3,Reciprocating Engines Environmental Benefits.
Reciprocating engines are the CHP plays an important role in. most common and most techni meeting the United States. cally mature of all CHP tech energy needs as well as in. nologies They are available from,reducing the environmental. small sizes e g 1 kW for,impact of power generation. residential generation to large,Because less fuel is burned to. generators e g 7 MW, Typically any power generation produce each unit of energy. system smaller than 20 kW is output CHP reduces air. considered micro CHP pollution and greenhouse gas, Currently available natural gas engines offer low first cost fast start up Natural gas CHP is the best choice for lowering carbon based.
proven reliability when properly maintained excellent load following emissions. characteristics and significant heat recovery potential. Electric efficiencies of natural gas engines range from 28 lower Carbon Emissions. heating value LHV for small engines 100 kW to over 40 LHV for 600. very large lean burn engines 3 MW Waste heat can be recovered. from an engine exhaust jacket water and oil cooling systems to 500. produce either hot water or low pressure steam for CHP applications. Overall CHP system efficiencies electricity and useful thermal energy. of 70 to 80 are routinely achieved with natural gas engine systems. Reciprocating engine technology has improved dramatically over the. past three decades driven by economic and environmental pressures 100. for power density improvements more output per unit of engine. displacement increased fuel efficiency and reduced emissions 0. Pulverized Coal Gasified Coal Combined Cycle Gas Fired CHP. Computer systems have greatly advanced reciprocating engine design Gas Turbine. and control accelerating advanced engine designs and making Source. Source EIA, possible more precise control and diagnostic monitoring of the engine EIA. process Engine manufacturers and worldwide engine R D firms. continue to drive advanced engine technology including accelerating According to the U S Energy Information Administration gas fired CHP. the diffusion of technology and concepts from the automotive and equipment offers the lowest carbon emissions versus alternate fueled. marine markets to the stationary market technologies Further additional exhaust treatments including Selective. Catalytic Reduction SCRs are available that can further improve the. total exhaust emissions,PAGE 4 PAGE 13,Site vs Source Combustion Turbines. Today energy efficiency and environmental impacts are on everyone s Conventional combustion. mind Understanding the real costs of the energy we consume in our turbine CT generators are a. buildings is also very important very mature technology They. typically range in size from, Statements about electricity being 100 efficient are misleading That. about 500 kW to over 300 MW, analysis simply focuses on the efficiency at the end use device an. for central power generation, energy using piece of equipment and doesn t take into account the.
They are fueled by natural gas, entire energy delivery process from generation to end use A. significant amount of energy is wasted just to produce the electrical. oil or a combination of fuels, power that is ultimately delivered to your facility dual fuel Modern single cycle. combustion turbine units, Natural gas comes directly from the well to your facility More natural typically have efficiencies in the range of 20 to 45 at full load. gas energy potential is delivered to your equipment on site making Efficiency is somewhat lower at less than full load. natural gas a far more efficient energy choice overall. Gas turbine CHP systems burn fuel to generate electricity and then. Industry analysis shows that the production transmission and delivery use a heat recovery unit to capture heat from the combustion. of electricity to the market has an overall efficiency of just 30 This system s exhaust stream This heat is converted into useful thermal. compares to natural gas at 90 energy usually in the form of steam hot water or heated air Gas. turbines are ideally suited for large commercial or industrial CHP. These numbers reflect the total energy expended during the. applications requiring ample amounts of electricity and heat. production through delivery process compared to the net energy. delivered for use, Gas turbines can be used in a variety of configurations 1 simple. cycle operation which is a single gas turbine producing power only. ELECTRIC 2 combined heat and power operation which is a simple cycle gas. turbine with a heat recovery heat exchanger which recovers the heat. in the turbine exhaust and converts it to useful thermal energy. usually in the form of steam or hot water and 3 combined cycle. operation in which high pressure steam is generated from recovered. exhaust heat and used to create additional power using a steam. about 70 lost in generation and delivery turbine Some combined cycles extract steam at an intermediate. pressure for use in industrial processes and are combined cycle. CHP systems,NATURAL GAS, Gas turbines produce high quality exhaust heat that can be used in.
efficient CHP configurations to reach overall system efficiencies of 70 to. 80 The efficiency and reliability of smaller gas turbines 1 to 40. about 10 lost in extraction and delivery MW are an attractive choice for industrial and large commercial. users for CHP applications,PAGE 12 PAGE 5, Microturbines very economical heat recovery options. Plate and frame heat exchangers are composed of multiple thin. Microturbines are small combustion slightly separated plates that have very large surface areas and fluid. turbines that produce between 30 kW and flow passages for heat transfer. 200 kW of power Microturbines were, derived from turbocharger technologies Shell and tube heat exchangers consist of a series of tubes These. found in large trucks or the turbines in tubes contains the fluid that will be either heated or cooled The. aircraft auxiliary power units APUs Most second fluid is in the shell and is pumped around the tubes to. microturbines are single stage radial flow transfer the heat to the initial loop. devices with high rotating speeds of 90 000, to 120 000 revolutions per minute Waste heat recovery process systems have many benefits for CHP. A few manufacturers have developed alternative systems with applications The recovery process adds to the efficiency of the CHP. multiple stages and or lower rotation speeds system decreasing the fuel and energy consumption needed for. other applications at the facility i e water or space conditioning. Microturbine generators can be divided in two general classes Other benefits can include the reduction in equipment sizes As fuel. consumption is reduced due to the recovered heat the size of the. equipment normally used for that application can be downsized. Recuperated microturbines which recover the heat from the. exhaust gas to boost the temperature of combustion and. increase the efficiency, Un recuperated microturbines which have lower efficiencies. but also lower capital costs, While most early product introductions featured un recuperated HIGH LOW.
designs todays products are focused on recuperated systems The TEMP TEMP. recuperator recovers heat from the exhaust gas and boosts the HEAT HEAT. temperature of the air stream supplied to the combustor Further the. exhaust heat recovery can be used in a CHP configuration The. figure below illustrates a recuperated microturbine system. Heat to users Generating Bank Economizer,Recuperator. Potential Electricity,waste heat recovery to Plant or. Utility Grid,Generator Shell Tube Heat Exchanger,Compressor Turbine. PAGE 6 PAGE 11,Waste Heat Recovery Steam Turbines, A waste heat recovery unit is a heat Steam turbines are one of the oldest prime. exchanger that recovers heat from exhaust mover technologies that are still used to. streams with potential high energy content drive a generator or mechanical machinery. such as exhaust gases or cooling water from a Power generation using steam turbines has. CHP system Numerous options exist for the been in use for over 100 years when they. use of waste heat including,replaced steam engines due to their higher.
efficiencies and lower costs Most of the,Steam Low Pressure and High Pressure. electricity produced in the United States, Hot Water today is generated by conventional steam. Chilled Water, turbine power plants The capacity of steam turbines can range from. 50 kW to 1 500 MW for large utility power plants Steam turbines are. There are many commercially available heat recovery systems and widely used for CHP applications in the U S and Europe. technologies, Unlike gas turbine and reciprocating engine CHP systems where. Heat Recovery Steam Generator HRSG, heat is a byproduct of power generation steam turbines normally.
Shell and Tube Plate Frame Heat Exchangers, generate electricity from heat steam A steam turbine is captive to. Absorption Chillers, a separate heat source and does not directly convert fuel to electric. energy The energy is transferred from the boiler to the turbine. A HRSG is a steam boiler that uses hot exhaust gases from the gas. through high pressure steam that in turn powers the turbine and. turbines or reciprocating engine to heat up water and generate. generator This separation of functions enables steam turbines to. steam The steam in turn drives a steam turbine or is used in. operate with a wide variety of fuels In CHP applications steam at. commercial applications that require heat, lower pressure is extracted from the steam turbine and used directly. in a process or for district heating or it can be converted to other. HRSGs used in the CHP industry are distinguished from. forms of thermal energy including hot or chilled water. conventional steam generators by the following main features. The HRSG is designed based upon the specific features of the Steam turbines offer a wide array of designs and complexity to. gas turbine or reciprocating engine that it will be coupled to match the desired application and or performance specifications. Since the exhaust gas temperature is relatively low heat Steam turbines for utility service may have several pressure casings. transmission is accomplished mainly through convection and elaborate design features all designed to maximize the. Exhaust gas velocity is limited by the need to keep head losses efficiency of the power plant For industrial applications steam. down which requires a larger heating surface area turbines are generally of simpler single casing design and less. Since the temperature difference between the hot gases and complicated for reliability and cost reasons CHP can be adapted to. the fluid to be heated steam or water is low a duct burner may both utility and industrial steam turbine designs. be incorporated into the exhaust stream to increase. temperatures, Heat exchangers are available in several configurations that offer. PAGE 10 PAGE 7,Fuel Cells Micro CHP, Fuel cells are an entirely different approach to Micro CHP systems in small commercial buildings are controlled by.
the production of electricity than traditional heat demand delivering electricity as the by product Although. prime mover technologies Fuel cell stacks similar to large CHP systems these small systems generate heat. available and under development are silent that is pumped through a heat exchanger and used for water heating. produce no pollutants have few moving parts or heating loads The generator provides power for on site. and have relatively high fuel efficiencies consumption and may exceed actual facility use In this case the. power can be sold back to the local electric utility lowering the total. Fuel cell systems with their ancillary pumps blowers and reformers operating cost. maintain most of these advantages A schematic of a fuel cell based. CHP system is shown below,Heating Loop,Buffer Tank. Inverter Heat,DC Exchanger,Processor Fuel Cell,Customer Engine Generator. Stack Load,Exchanger E Inlet,21 O2 Cooling Loop, Fuel cells produce power electrochemically from hydrogen delivered to Excess Power Electricity to Building. the negative pole anode of the cell and oxygen delivered to the to Grid. positive pole cathode The hydrogen can come from a variety of. Small scale fuel cells can also be used for micro CHP applications. sources but the most economic method is by reforming of natural gas. There are several different liquid and solid media that support these. electrochemical reactions phosphoric acid PAFC molten carbonate. MCFC solid oxide SOFC and proton exchange membrane PEM. are the most common systems Each of these media comprises a. distinct fuel cell technology with its own performance Fuel cell. efficiencies range from 35 40 percent for the PAFC to upwards of 60. percent for the SOFC systems,PAGE 8 PAGE 9,Fuel Cells Micro CHP. Fuel cells are an entirely different approach to Micro CHP systems in small commercial buildings are controlled by. the production of electricity than traditional heat demand delivering electricity as the by product Although. prime mover technologies Fuel cell stacks similar to large CHP systems these small systems generate heat. available and under development are silent that is pumped through a heat exchanger and used for water heating. produce no pollutants have few moving parts or heating loads The generator provides power for on site. and have relatively high fuel efficiencies consumption and may exceed actual facility use In this case the. power can be sold back to the local electric utility lowering the total. Fuel cell systems with their ancillary pumps blowers and reformers operating cost. maintain most of these advantages A schematic of a fuel cell based. CHP system is shown below,Heating Loop,Buffer Tank.
Inverter Heat,DC Exchanger,Processor Fuel Cell,Customer Engine Generator. Stack Load,Exchanger E Inlet,21 O2 Cooling Loop, Fuel cells produce power electrochemically from hydrogen delivered to Excess Power Electricity to Building. the negative pole anode of the cell and oxygen delivered to the to Grid. positive pole cathode The hydrogen can come from a variety of. Small scale fuel cells can also be used for micro CHP applications. sources but the most economic method is by reforming of natural gas. There are several different liquid and solid media that support these. electrochemical reactions phosphoric acid PAFC molten carbonate. MCFC solid oxide SOFC and proton exchange membrane PEM. are the most common systems Each of these media comprises a. distinct fuel cell technology with its own performance Fuel cell. efficiencies range from 35 40 percent for the PAFC to upwards of 60. percent for the SOFC systems,PAGE 8 PAGE 9,Waste Heat Recovery Steam Turbines. A waste heat recovery unit is a heat Steam turbines are one of the oldest prime. exchanger that recovers heat from exhaust mover technologies that are still used to. streams with potential high energy content drive a generator or mechanical machinery. such as exhaust gases or cooling water from a Power generation using steam turbines has. CHP system Numerous options exist for the been in use for over 100 years when they. use of waste heat including,replaced steam engines due to their higher. efficiencies and lower costs Most of the,Steam Low Pressure and High Pressure.
electricity produced in the United States, Hot Water today is generated by conventional steam. Chilled Water, turbine power plants The capacity of steam turbines can range from. 50 kW to 1 500 MW for large utility power plants Steam turbines are. There are many commercially available heat recovery systems and widely used for CHP applications in the U S and Europe. technologies, Unlike gas turbine and reciprocating engine CHP systems where. Heat Recovery Steam Generator HRSG, heat is a byproduct of power generation steam turbines normally. Shell and Tube Plate Frame Heat Exchangers, generate electricity from heat steam A steam turbine is captive to.
Absorption Chillers, a separate heat source and does not directly convert fuel to electric. energy The energy is transferred from the boiler to the turbine. A HRSG is a steam boiler that uses hot exhaust gases from the gas. through high pressure steam that in turn powers the turbine and. turbines or reciprocating engine to heat up water and generate. generator This separation of functions enables steam turbines to. steam The steam in turn drives a steam turbine or is used in. operate with a wide variety of fuels In CHP applications steam at. commercial applications that require heat, lower pressure is extracted from the steam turbine and used directly. in a process or for district heating or it can be converted to other. HRSGs used in the CHP industry are distinguished from. forms of thermal energy including hot or chilled water. conventional steam generators by the following main features. The HRSG is designed based upon the specific features of the Steam turbines offer a wide array of designs and complexity to. gas turbine or reciprocating engine that it will be coupled to match the desired application and or performance specifications. Since the exhaust gas temperature is relatively low heat Steam turbines for utility service may have several pressure casings. transmission is accomplished mainly through convection and elaborate design features all designed to maximize the. Exhaust gas velocity is limited by the need to keep head losses efficiency of the power plant For industrial applications steam. down which requires a larger heating surface area turbines are generally of simpler single casing design and less. Since the temperature difference between the hot gases and complicated for reliability and cost reasons CHP can be adapted to. the fluid to be heated steam or water is low a duct burner may both utility and industrial steam turbine designs. be incorporated into the exhaust stream to increase. temperatures, Heat exchangers are available in several configurations that offer. PAGE 10 PAGE 7, Microturbines very economical heat recovery options. Plate and frame heat exchangers are composed of multiple thin. Microturbines are small combustion slightly separated plates that have very large surface areas and fluid. turbines that produce between 30 kW and flow passages for heat transfer. 200 kW of power Microturbines were, derived from turbocharger technologies Shell and tube heat exchangers consist of a series of tubes These.
found in large trucks or the turbines in tubes contains the fluid that will be either heated or cooled The. aircraft auxiliary power units APUs Most second fluid is in the shell and is pumped around the tubes to. microturbines are single stage radial flow transfer the heat to the initial loop. devices with high rotating speeds of 90 000, to 120 000 revolutions per minute Waste heat recovery process systems have many benefits for CHP. A few manufacturers have developed alternative systems with applications The recovery process adds to the efficiency of the CHP. multiple stages and or lower rotation speeds system decreasing the fuel and energy consumption needed for. other applications at the facility i e water or space conditioning. Microturbine generators can be divided in two general classes Other benefits can include the reduction in equipment sizes As fuel. consumption is reduced due to the recovered heat the size of the. equipment normally used for that application can be downsized. Recuperated microturbines which recover the heat from the. exhaust gas to boost the temperature of combustion and. increase the efficiency, Un recuperated microturbines which have lower efficiencies. but also lower capital costs, While most early product introductions featured un recuperated HIGH LOW. designs todays products are focused on recuperated systems The TEMP TEMP. recuperator recovers heat from the exhaust gas and boosts the HEAT HEAT. temperature of the air stream supplied to the combustor Further the. exhaust heat recovery can be used in a CHP configuration The. figure below illustrates a recuperated microturbine system. Heat to users Generating Bank Economizer,Recuperator. Potential Electricity,waste heat recovery to Plant or.
Utility Grid,Generator Shell Tube Heat Exchanger,Compressor Turbine. PAGE 6 PAGE 11,Site vs Source Combustion Turbines, Today energy efficiency and environmental impacts are on everyone s Conventional combustion. mind Understanding the real costs of the energy we consume in our turbine CT generators are a. buildings is also very important very mature technology They. typically range in size from, Statements about electricity being 100 efficient are misleading That. about 500 kW to over 300 MW, analysis simply focuses on the efficiency at the end use device an. for central power generation, energy using piece of equipment and doesn t take into account the.
They are fueled by natural gas, entire energy delivery process from generation to end use A. significant amount of energy is wasted just to produce the electrical. oil or a combination of fuels, power that is ultimately delivered to your facility dual fuel Modern single cycle. combustion turbine units, Natural gas comes directly from the well to your facility More natural typically have efficiencies in the range of 20 to 45 at full load. gas energy potential is delivered to your equipment on site making Efficiency is somewhat lower at less than full load. natural gas a far more efficient energy choice overall. Gas turbine CHP systems burn fuel to generate electricity and then. Industry analysis shows that the production transmission and delivery use a heat recovery unit to capture heat from the combustion. of electricity to the market has an overall efficiency of just 30 This system s exhaust stream This heat is converted into useful thermal. compares to natural gas at 90 energy usually in the form of steam hot water or heated air Gas. turbines are ideally suited for large commercial or industrial CHP. These numbers reflect the total energy expended during the. applications requiring ample amounts of electricity and heat. production through delivery process compared to the net energy. delivered for use, Gas turbines can be used in a variety of configurations 1 simple. cycle operation which is a single gas turbine producing power only. ELECTRIC 2 combined heat and power operation which is a simple cycle gas. turbine with a heat recovery heat exchanger which recovers the heat. in the turbine exhaust and converts it to useful thermal energy. usually in the form of steam or hot water and 3 combined cycle. operation in which high pressure steam is generated from recovered. exhaust heat and used to create additional power using a steam. about 70 lost in generation and delivery turbine Some combined cycles extract steam at an intermediate. pressure for use in industrial processes and are combined cycle. CHP systems,NATURAL GAS, Gas turbines produce high quality exhaust heat that can be used in.
efficient CHP configurations to reach overall system efficiencies of 70 to. 80 The efficiency and reliability of smaller gas turbines 1 to 40. about 10 lost in extraction and delivery MW are an attractive choice for industrial and large commercial. users for CHP applications,PAGE 12 PAGE 5,Reciprocating Engines Environmental Benefits. Reciprocating engines are the CHP plays an important role in. most common and most techni meeting the United States. cally mature of all CHP tech energy needs as well as in. nologies They are available from,reducing the environmental. small sizes e g 1 kW for,impact of power generation. residential generation to large,Because less fuel is burned to. generators e g 7 MW, Typically any power generation produce each unit of energy.
system smaller than 20 kW is output CHP reduces air. considered micro CHP pollution and greenhouse gas, Currently available natural gas engines offer low first cost fast start up Natural gas CHP is the best choice for lowering carbon based. proven reliability when properly maintained excellent load following emissions. characteristics and significant heat recovery potential. Electric efficiencies of natural gas engines range from 28 lower Carbon Emissions. heating value LHV for small engines 100 kW to over 40 LHV for 600. very large lean burn engines 3 MW Waste heat can be recovered. from an engine exhaust jacket water and oil cooling systems to 500. produce either hot water or low pressure steam for CHP applications. Overall CHP system efficiencies electricity and useful thermal energy. of 70 to 80 are routinely achieved with natural gas engine systems. Reciprocating engine technology has improved dramatically over the. past three decades driven by economic and environmental pressures 100. for power density improvements more output per unit of engine. displacement increased fuel efficiency and reduced emissions 0. Pulverized Coal Gasified Coal Combined Cycle Gas Fired CHP. Computer systems have greatly advanced reciprocating engine design Gas Turbine. and control accelerating advanced engine designs and making Source. Source EIA, possible more precise control and diagnostic monitoring of the engine EIA. process Engine manufacturers and worldwide engine R D firms. continue to drive advanced engine technology including accelerating According to the U S Energy Information Administration gas fired CHP. the diffusion of technology and concepts from the automotive and equipment offers the lowest carbon emissions versus alternate fueled. marine markets to the stationary market technologies Further additional exhaust treatments including Selective. Catalytic Reduction SCRs are available that can further improve the.

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