Combined Heat & Power: A Federal Manager's Resource Guide

1 Combined heat & Power: A Federal manager s Resource GuideFinal ReportPrepared Department of EnergyFederal Energy Management ProgramWashington, DCPrepared by:Aspen Systems CorporationApplied Management Sciences Group2277 Research BoulevardRockville, MD 20850 March 2000 Table of ContentsAbstract .. Technologies of Combined heat and Sector Potential .. Performance .. heat and power Case Studies .. for CHP Technology: Strategies for Success .. Program and Additional Sources of Information ..22 AppendicesAppendix A: Former Federal Combined heat and power Sites ..24 Appendix B: Federal Life-Cycle Costing Procedures and the BLCC Software ..25 Appendix C: Acronym Glossary.

2 26iiCombinedHeat andPower:A FederalManager sResourceGuideAbstractExecutive Order 13123 Green-ing the Government Through Efficient Energy Management,identifies in Section 403(g) thatFederal facilities shall use com-bined cooling, heat and powersystems when life-cycle cost effec-tive to achieve their energy reduc-tion goals. This is a renewedemphasis placed by the Federalgovernment on implementation oftechnologies that achieve overallsystem energy efficiency, reducegreenhouse gas emissions, and trimoperating expenses. FEMP createdCombined heat and power : AFederal manager s ResourceGuideto assist in this heat and power (CHP) is a master term for onsitepower generation technologiesthat simultaneously produce elec-trical or mechanical energy anduseful thermal energy.

3 Cogenera-tion has existed for more than 100 years and is now achieving a greater level of acceptance dueto increased reliability andover-all cost efficiency. Capturing andusing the thermal energy producedas a byproduct from fuel sourcessuch as oil, coal, or natural gas,increases the power gained fromthe original fuel source. CHPtechnologies have the potential to reduce energy consumption decreasing energy bills, as well as pollution. Internal combustion enginesand combustion turbines are twoCHP technologies currently usedin industrial, commercial, andgovernment facilities across thenation. Two exciting new CHPtechnologies are fuel cells andmicro-turbines. Fuel cells producepower electrochemically (like abattery) except that they consumefuel (hydrogen) to maintain thechemical reaction.

4 Fuel cells haveno moving parts and provide aquiet, clean, and a highly efficientsource of onsite generation withthermal outputs. Fuel cells pro-duce low levels of pollutants and,although still too expensive formany applications, are slowly becoming economically viable. Micro-turbines are scaled downversions of combustion turbinesthat provide reasonable efficiency,require minimal maintenance,allow fuel flexibility, and have lowemissions. Hybrid systems thatutilize the best features of bothfuel cells and micro-turbines arealso being tested. Combined heat and Power: A Federal manager s ResourceGuideidentifies the short-,medium-, and long-term potentialof internal combustion engines,combustion turbines, fuel cells,and micro-turbines for Federalfacilities.

5 It outlines successfulapplication procedures for theseCHP technologies and providescase studies of successful imple-mentations. Sources for additionalinformation on CHP technologiesare listed at the end of this TheTechnologies ofCombined Heatand power Combined heat and power (CHP), also known as cogenera-tion, is a system that efficientlygenerates electricity (or shaft pow-er) and takes advantage of the heatthat is normally not used, to pro-duce steam, hot water, and/orchilled water. DOE has estimatedthat about seven percent of the totalelectrical power generation in thiscountry is produced by CHP equip-ment. The Department of Energy(DOE) has recently introduced anew initiative that includes spacecooling to the useful energy out-puts of these Combined energy sys-tems, and has designated this asBuildings Cooling, Heating andPower BCHP.

6 The specific cool-ing technologies and details of itsapplication will be included in fu-ture editions of this 2 1 visually depicts theconcept of CHP because the ener-gy input to the system is used togenerate both electrical power anduseful thermal before the energy crisis ofthe 1970s, waste heat from powerplants was used for thermal appli-cations. Thomas Edison s firstpower plant utilized waste heat forsteam that he sold to help pay gen-erating expenses. Unfortunately,because of central station utilities,the practice of CHP decreased formany generations, even thoughwhen applied well, it significantlyimproved the efficiency of a pow-er plant. In this new era of electric utilityrestructuring, there is a renewedenthusiasm for CHP, stemmingfrom the promise of lower total lifecycle operating costs, environmen-tal compliance, and system relia-bility.

7 CHP is not limited to onetechnology, but rather is applicableto a growing array of productsdesigned to help Federal facilitiesmeet their onsite generation proven technologies (inter-nal combustion engines, steamturbines, combustion {gas} tur-bines, fuel cells, micro-turbines)can provide useful thermal energyfor a variety of building applica-tions (see table 2 1) as well aselectricity for base load, peakshaving, or backup situations. Table 2 1. Waste heat ApplicationsSpace heatingDomestic hot water heatingBoiler feed-water preheatingSteam generation to supplyturbines ( Combined Cycle)Pool water heatingSteam/hot water for absorptionchillerProcess hot water/steamCogeneration is defined by theAmerican Society of Heating, Re-frigerating, and Air ConditioningEngineers (ASHRAE), as the si-multaneous production of electri-cal or mechanical energy ( power )and useful thermal energy from asingle energy stream, such as oil,coal, or natural gas.

8 In certain lo-cations, the energy source can beprovided from solar, geothermal or biomass. Several technologiesproduce both electrical energy andthermal energy. This chapter pro-vides an overview of the Internal Combustion Steam Combustion (Gas) Fuel Hybrid fuel cell/micro-turbine Internal CombustionEngine One of the original cogenerationtechnologies is the reciprocatinginternal combustion (IC) generator sets produceelectricity along with waste heat2 THERMALOUTPUTGENERATORELECTRICITYHEATFUE LTURBINE,ENGINE ORFUEL CELLF igure 2 1. Combined heat and power Systemthat can be captured for a varietyof building thermal needs. IC engines are the fastest grow-ing segment of the small size (1 to10 MW) CHP market for systemsthat use heat diverted to a engines have outsold turbines18-to-1 in the 1 to 5 megawattrange largely because they havehigher electric generating efficien-cies than gas turbines in this sizerange.

9 (Based on DOE studies.) A large majority of the smallerIC engines use diesel or gasoline to provide backup power to facili-ties during emergency situations orpower outages. Traditionally, thesegenerators were noisy, dirty suppli-ers of electricity without employingthe benefits of heat recovery exhausting heat directly into theatmosphere instead of capturing itfor useful building purposes. Today, manufacturers are pro-ducing variously sized (down to25 kW) natural gas-powered,high-output, and highly efficientpackaged cogenerators that areused in a variety of small- tomedium-sized building applica-tions. These modular, quiet, andclean engines are used not only in backup or peak shaving situa-tions, but also to supply base loadelectricity to a growing number of facilities.

10 Packaged IC enginescan provide Federal facilities withthe following (relative to otherCHP technologies): Low start-up costs Reliable onsite energy Low operating costs Clean energy Ease of maintenance Wide service infrastructureDOE currently sponsors theAdvanced Turbines and EngineProgram (ATEP) to assist industryin developing cleaner, more effi-cient heat engines through fundingfor R&D and prototype 2 2 represents a heat en-gine and the possible efficiencyopportunities that can lead to lower operating RecoveryWaste heat has never been cap-tured to its potential from smallerIC engines because IC engineswere traditionally used in backupor peak shaving situations.