IO
`
`I
`
`CI-I-9-5- 1Q-4
`
`'
`
`INNOVATIONS IN DISTRICT HEATING
`AND COOLING 1934-1994 AND
`
`I
`
`THEIR ECONOMIC IMPACT
`
`Gqran llfiomhed
`
`RBSTRACT
`
`Thomas R. Casten
`
`ing Owners take a hardar look at 1113 costs associated wiih
`self-gcrlcratimn. W'.|:I:n 111:5:-.
`factors are added to Ihe
`tcchnala-gical innovations of district heating and cooling, 3
`syncrgy developed that propelled 11-Ie popularity of‘ district
`heating and cooling to a -new high.
`This paper fwas on the innovations in the technology
`the: fomaed DEB pan in the revival. Exisfing district energy
`systems were able to I'J1'11:IIO-n: ‘Ihcir economic feasibility, and
`new systems wen: built using ncw C051-efiective -I:|i5I:ributiO-fl
`technology. Distriact cooiing, which had bean largr.-I}' limited
`to campus systems, experienc led an unprecedented expansion
`in downtown I.I.rban cters.
`
`In this new c:rIvirOI:m1ent_ the term I-i:';s-zré-:1 Energy came
`into use to describe: ntilizafinn of that: innovations in the
`combination of heating and cooling servicas, and it be.I:arI:n:
`clear that the fi.'II!'I.I:I-I: of thz business was in providing, "cam:
`fmt,” not sellirighzat.
`
`INNOVATIONS IN DISTRICT
`HEFLTING AND COOLING
`
`771%! periadfiwzm 1934 30 I994 Jaw flit.’ concepf afcT.r-
`trfcr Insuring and coaaijlrzgreviw-Isri May: New dixlricf .-znergy
`ysrems were errablirhecf and garfsting ;3..u-ram:
`.,;-zzpa-m;:Ied‘_
`7?:-E Expaflsforr car: -52 aflribufed to technical irinavarforls m
`wgfl av: I'n.m'::.:I':I'a.-Iaf. em.-frarmentafi and economic changes;
`no one even! can be .s'I‘:1gI’ea' out as a main r£a.sorr_,l'br the im-
`proved climate’. The: rfirrricr coofing industry in p:n"I'J'cIo'k2r.
`fit-En’-<.*d'
`grcrwing detwand and rec-'1nI'ca'I' i.n.-2o1I£ru'o.=w, £Igpen‘-
`errced 4:: pea-fad qr’ w-Iprecederuezi ezpmzsion. 03-: the .sr.ra-_-f:u.-.-.-=.-,
`the conczpl of aII'.s*.*ri:.'I goofing would appear Io be 1.I.ru=.1::&-
`I-Io:-m'cal. Although economic bcznefitr can be achieved 1.I.:.r'.=:'g
`a'raa'I'rEoI:IaI’ ::’:'.I'rr:iI:f c0o.’.I'ng rechndagy aver E:-;I¢fI.-:'r:i'u.I-:n‘ build-
`ing .r_vSre:n.r, fhe beI-:I=.;fir.s finam technical innovation: dun‘.-zg
`the last 19 years. ruck as lowrengperafnre c3:.I'1'!a:!—1u-aI.9:'
`storage. Irigenerafian, varfabfe-speed-drh-a me-1::-Ia¢’og].:. and
`maromaxfon, hmre made dirrricf Cooling more compeffrivne
`am! F‘.-cue: conrribmed to Irnfiwrty growth. On the district
`henfiwrg 51252. hztrmrarforzr such as fo°H--con‘ dirlriburfan rec}:-
`rlalogv and cast-e.;{?Ea::£hIe cagenerafian helped create a re-
`m;I.='.s'.sa.-.-c-.e_ The :‘m;.-rob-e.d' camperitivenau qfdisrrfcr hearing
`and cooling kn: made the comb:'nen".::rvr‘.:.-2 azxracrivefar us-
`er: who now do .-:0: need to rafy on either Era-1:01:99 heating
`or cooling plr.-Mrs. O.rJgcN'.r:g fnnovariorzr in the .'r"na'usI‘r3- set
`the stage for cornfnued expansion as dirtrfci PI-earing and
`z:ooifng—-dislrici energ}-—moue Into the next czenmry and
`help improve our rrrfi-cm ea-ruI'rarn-I-rent more than ever.
`
`INTRODUCTION
`
`hicrnasingiy during the last few decades and espctially
`during the last II} }-Lars, tI:I:l:Ir.IJ'::a] in-_nnva.l.ions have bean a.
`driving force: behind the cunzinuing expansion of -Eli.-slaiclt
`heating and cooling. These ilrinmrations have improved‘. the
`BIJO]1DI]'liC5 Ofexistlng systems arid rrlade the development Of
`new ans feasible.
`in
`The district heating and cooling indusfly is small
`Comparison to other technology-related industnias, such as
`powerguneration. Although there cenainiy have been Ii:-.-e]~
`npmemss made by the district heatisng and cooling industry, in
`many cases technology developed for mher fields has been
`Du.i'1'J1g the last decade, the concept cf district heafing
`and c:::-1:I-ling, was revisalized and district energy became an in-
`successfizlly applied. Innovations such as large-scale chilled-
`watcr storage and low-cost dish-ibution piping an: axarrnples
`cruasingly vital bencfactor to 05.1: major urban centers. This
`growth from 1984 to 1994 can be attributed In tecimical in-
`Of the former, while effiI:i-mt cogenaration technology ami
`novations as well as institlnionai, vimmnentral, and e::Cr~
`process automafian an: C:aI:I1pIes of 'L‘|-II: latter. Applications
`Of these I'J111avations and the beneficial ;r¢su]t5 from them, are
`ncrmic changes- It was dm-ing this patriot! that Cornpanics
`be-me out by the cxperiextce in disnict energy sysmns oper-
`decided to focus on their core business. Devoting ‘time and
`rcsI:ru.'cI:s to the nperatiun of healing and cuoling cq-uipme:n1:
`ated by the authors mid crthms in, for exa.mpIc_ Tulsa, OK.
`Chicago, IL, SL Paul, MN. and elsewhere.
`unreiated to a company’; business made less and Eggs sense
`Dizlficl heating and cooling is capital intensive and on
`in increasingly difficult and competitive times. A: the same
`timfi. mare Environmental regulations, including the phase-
`the surfhcc appeal’: to ofiezr few operational Cost. savings
`
`compared to in—l1ousI: heating and mnling. However.out Of chlorufiuorucarbons {CI-‘-C5), made 'mdiviI:hnI b1,t:]d-— Ihr:
`
`
`Goran Marnhed is prcjact marngc.-r and Thomas R. -C1.-.1en is presidmt and CEO all Trigcn Encrg-_-.r CO1-polatiun, 'Wl'sirc Plains, NY.
`'11-115 I=~nEI=m:-.n- .5 Fan nuscussnfi PUFI‘PI'_'I»SES_ON'LY. FDFI INI:1.LI_sJDN_Iu A51-{RAE TIU.u5_J~.r:T'1I:I_\I$ 1955, 1.’. 1:11, P1. 1.Na-[In berepI'in1ed _In_.-«hula cur
`in pan wiI11ouIwr'IIterI pennissinn at lha Amerlszan socaetv ul Haafing. Flnlngmlmq and Air-CurrdTI‘-anwg Engineers. Inn. 1 :91 Tom: cin~.I=. HE. Manta.-I:-EA 3U:=29.
`Depinlwna. firvu‘-ngs, conclusions. urr-anmrrtendhliuns art!‘-H‘!-‘e’-Sclil In his pas:-erale In-ose ol the au:hnrI:sJ andda not necessarify reIIe;| u'u:1.iie|-vs d‘ ASP-IE'h_°IE\'\I'I1tIeI1v
`quasliuns and GDrI'II'I1En:ls regarding Iris panel’ Shflwd be "=°=T'IM='d Bl ASHFME no Ialar Elan Fabruary 3. [E95,
`
`
`
`PAGE 1 of 6
`
`PETITIONER'S EXHIBIT 1027
`
`

`
`
`
`1t.El':::u:tl1‘:rg_*{ offers much fleflbility in selecfnig the most eco-
`nomic method of supplying a large pooled heating and cool-
`ing demand.
`'
`'
`An isolated building is limited to the use of installed
`equipment, normally sized on a rareiy seen peak load. A
`pooled energy -detnand can be met from multiple plants using
`different technologies. Difiuent technologies are used to
`meet base load and peel: demand, withtbe selection basedon
`maximizing the efficiency? of each piece of equipment and
`miriilnizing fuel costs. Cogene-ration of heating and cooling
`or heating and power furttter enhances efficiency. Thermal
`storage systems are employed to reduce electric peak de-
`mand. As a technology, district energy offers unlimited flex-
`ibility For optimizing the eflicienc-y of boll: beating and
`cooling.
`.
`The innovations made during the last decade have sig-
`ttificaaitly improved the technology by
`
`v
`
`-
`
`-
`
`-
`
`increasing the efficiency of chilled-water production
`(using rurbirtevclriven reli-igeration, chi11ed—wate:r stor-
`age, and so forth),
`increasing the efiiciettcy ofstearn and hot water produc-
`tion {improved efiicieru.-y in boilers and hot water gen-
`craters},
`irrtprovirig the efficiency of combined beating and cool-
`ing (cogcrteration and trigenet-ation), and
`reducing the cost of distribution systems (improved
`prefabricated pipirtg for direct burial, more effective
`variable ptllnping, etc.)
`
`As a result, district energy can today be developed at a lower
`specific cost, with a higher efficiency, and with more flexi-
`bility than ever before.
`
`Cogeneratien
`
`Cogeneration as a concept hardly-' counts as an innova-
`tion after a century or more or" use. However, after decades
`of limited potential, cogerteretion has been revived through
`todmical inltovations.
`_
`I
`lmproverncnts in gas turbine technology have greatly
`E:t'!.l:I.:II'lCEt'l. their mechanical efi_lCiEI1C‘_|;‘ and. "P-'hBI‘I= D-1!?-11171] 3&5
`fiuel is available. gas turbines are today increasingly replac-
`ing,
`steam turbines
`in
`cogcncration
`applications.
`Traditionally, the seasonal heating loads in district heating
`systems limited the economical size or‘ the back-pressure
`stearu turbine; the turbine had to be sized based on a fincfion
`of the winter peak steam flow to allow economical operation
`during most oftlie year. The relatively small turbines im-
`posed a practical iitnitation on system steam data and turbine
`emciency- As a result, most back-pressure steam turbines in
`district heating 5}! stems were relatively small and incfficicnt.
`Alternatively, i:I1temai combustion engines provided a higher
`mechanical efficiency but, in most cases, a lower therrnal ef-
`ficiency and limited steam production.
`
`The irutovarions in gas turbine tcchnoiogyr have pro-
`duced 3. Iuecliirte that combines small sine and light weight
`with high mechanical efficiency and high exhaust tempera-
`ture. In cog-eneratinn applications, producing both steam and
`electricity, they combine the desirable chzu-ecteristics ofbigh
`mechanical efficiency (30%: to 40%) with high thermal effi-
`cicnrqf (':'{l'.’v‘E to 80%}. Moreover, efficient gas turbines are
`today available, as evidenced by current manufacturer litera-
`ture, in a. wide size 1-nrige-—fiom less than 1,0I}E}I horsepower
`{hp} (ff-"SD kw] to more than 1tlllI,l}IJl}hp (‘£5,000 k‘W)t
`Large gas turbines can be sized based on steam load,
`maetirnizing electric production for the 31316. while smaller
`gas turbines can be advantageously used as chiller drives or
`purnp drives, with recovered steam used to supplement
`boiler steam in the distribution system. In mechanical drive
`applications, steam from the turbi.ne exhaust can tnaltca sig-
`nificant contribution to the steam production throughout lhe
`summer semort. Excess steam not required for -I:listribLrtion
`can be used for producing chilled water in absorption or
`stearu turbine chillers.
`_
`'
`Additional
`iuprotreruents in gas turbine technology,
`such as combustion air cooling. and duct firing, can easily be
`incorporated into a district energy facility, and help to fur-
`ther improve the cost-efiectivcncss ofthe installation. Com-_
`bustion air cooling, which can be provided for through a
`chilled-water ‘or refrigerant coil in the combustilzm air intake,
`will alleviate ‘line problem of gas turbine dcratuig at high am-
`bient ternpe-..'et|.u'es when the gas t1:Lrbi1'u= electric power is
`most ‘valuable. Duct Ftling allows the warm mrbinc EXl1EI.|'."-T
`to be used as preheated combustion air to generate additional
`steam at a very high efficiency.
`
`Trigerreration
`
`“Trigenera.tion” is an extension ofcogencration technol-
`ogy that
`involves the simultaneous generation of heat,
`chilled water, and t:I.c-t:tt'icit3-'. The trgencration machines de-
`veloped for district energy systems in the last few years fee-
`nm: a prime mover connected to an induction generates!
`motor and a ehfller screw compressor on the me shaft (Fig-
`ure 1). In this way, any combination ofatatutal gas and elec-
`tricity can be used to drive the
`screw compressor.
`Corrversely, flit: shaft power produced by Lhe prime mover
`can be used to generate electricity and chilled water in arty
`proportion. The dirt! product, heat,
`is generated ofi the
`prime mover exhaust.
`Ttigeneration technology can be advantageously applied
`to idistrict energy facilities that produce both heating and
`cooling, especially if a thermal storage tank is incorporated
`in the system and the machines can operate 24 hours per day.
`Th: relatively high initial cost of the tr1'genera1ion technol-
`ogy in such a plant is more than offset by the machines high
`utilization: gas—fi.'Le1eci cooling, auxiliary power genemtion.
`and eloctrit: peak shaving, all at a high thermal elliciency of
`70% to 80%. Fl.ll"|lJC.'l'l'l‘lOt['C, since a combination of these uses
`
`CH-95-ID-I1
`
`
`
`PAGE 2 of 6
`
`PETITIONER'S EXHIBIT 1027
`
`

`
`Ftgzlre I Conczpi affrI'generr:t|':'on_
`
`e:-cists year-round, the machine‘: load factor: are typically
`high. Existing insuaflatious typicaily operate at full load for
`5,GO0 to 7,005 It-ours per year.
`Compared to ‘traditional heating and cooling plants, the
`properly applied nigertenttion machine will produce chilled
`water at a net cccfficicnt ofpcrformancc (COP) cfbcrwcen 3
`and 4, a higher 11:: efficiency than any oihcr commercially
`available ga5.'ch.i1Icd—watI'er technology {Figure 2) (Ca.-sten
`1994). Note: In Figure 2, the CO? is based on 1,000 Bmfft-°'
`ofnamrai gas. These chta have been validated. by district e:n—
`ergy plant operation in Tulsa and Oklahoma City, OK.
`
`Large-Scale chilled-Water Starage
`
`The period 1934-1994 saw the development of 1argI:+
`scale thermal storage- Earlier, small-scale themtal storage 1‘:-
`cilities, such as ice signage and membrane Ianb, were used
`in limited applications. In the 1980:, however, 1a:gc—sca]e
`stratified chilled-waiertanits were beginning to be used (An-
`tkepnnl I992).
`-
`Chilled-water storage I;a.11l(s provide a n1.IJ11ber of bene-
`fits to district cooling systems, including tl1e_fo-llurwing.
`
`J. Expensive base-load chiller capacity can be fully uti-
`lizcd 24ll:nurs per day, efiecfively doubling is capacity
`for most applications.
`I
`2. Eiectric chillers can be operated “ofl'pea.k” and electric
`demand charges minirrlized (load shjfiirlg}.
`3. The c]:lilIe:I's am be operated at optimurn efiiciency to
`charge thenank, and the tank can then be discharged on
`an as-required basis.
`4. The storage tan]: provides an 1'.I151:EnI'.aIJeOI.l3 chilled-
`watcr backup.
`'
`
`flaighcst density of water}. In siratified storage tanks, cold‘
`water is stored inthe bottom of the tank. As it is used for
`1:1:-c-ling, it is returned warm to the top ofthe tank. The water
`is charged and discharged as larrtinar flow at very low flow
`rates. Because of the higher density cf the colder water and
`the low charging velocity, the water stratifies in Lhe tnrLlc and
`only 2:. 2- to 3-foot {fl.6l— to -D.91—meter) disturbed laycr—a_
`the:':noclit:1e%epm-ates the wann and cold water (ASI-IRAE
`1993;. CB&lC 1989}.
`The d11I\-(back with these tanks is mat users with in-
`crea.=;iI1giy common 34‘IF (] .]"C) r_|1i]1ed—water systems an-
`not be served fmm the tank A recent development
`(inexpensive fi'ce.ziI1g-pa:-int depressant} has suhned the prob-
`lem and pm-duced tanla that strttifi- to 15°F {-3-.9"C) or less
`(Figure 3). The lou-—tcmpera.tIJrc strarifi-::r:I slonigc offers
`many improvements over the tradition-al slzrafified tank:
`
`'
`
`doubling of L11: thennal capacity tlunugh an i.n-crease in
`the telnpcrature di1‘Terentiai—3{!"Ff54"F instead of
`42"F."5-rl'“'F [—C|.2°CJ'l2.2°C instead of5.5°CJ'122"C},
`
`{'.|=,ntgn.m
`NaturalGasC.5r|1urrLp1|on.
`
`
`HIEI HIGDVII1‘
`
`In the mid-19805, tan]:-‘. were developed in which chilled-
`wazer would stmtify down to a temperamre of 39°F (3.9"-C)
`
`Figure 2
`
`Chffier energy censumplfan.
`
`CH-95-I 0-4
`
`
`
`PAGE 3 of 6
`
`PETITIONER'S EXHIBIT 1027
`
`

`
`
`
`$l'F l1'i'-'-".'l
`
`i
`
`
`
`Figure 4
`
`Typical series ciriiffng concepr.
`
`increased -use of industrial ammonia refrigeration for district
`coolirlg.
`Compared to other refrigerants, arnrnortia stands out as
`not only one -of the most eifioicnt rcfiigorants, but also the
`most acceptable from an environmental point of view. Arr.-
`monia has no impact on the ozone layer and no gnaenhous-c
`cficcf. Intact, 1.-astamouots ofammonia are-used as agricul-
`tural fertilizer. Ammonia is generaliy ararailable at a tenth or
`less ofthe cost ofotherrefrigesants.
`Ammonia vapour has a iow density and tlnereforer is d_ii“fi-
`cult to use in centrifugal conspressocrs. However. modem
`screw co1npr¢sso1‘5 that feature variable compression are ide-
`ally snincd to district cooling. Using ammonia screw com-
`pressors,
`the cooling tower we:-bulb approach can be
`maintained in a wide temp-claim‘: range and the resulting
`colder condenser wan.-.-r advantageously used in the cooling
`plant, with the lower condenser water tcrnpcmture, a lower
`compression E required and less compressor power con-
`mcd. Anunonia screw compressors compare in efficiency
`to modern centrifilgal chillem at design conditions and can
`be operated at full capacity at less than 0.3 ltwfton using
`40°F (4.4-°C) condenser water temper-snare {Figure 5). Note:
`In Figure 5, flue values are based onmanufacturers’ published
`
`,
`50
`
`4-1)
`
`'
`
`3'0
`54!
`Con-dII'|.:uhI' Walar Tom;-eI1-lure
`
`51!
`
`in ‘F
`
`e ‘:2
`to
`an
`an
`
`o.'.I
`
`'”
`o.s
`9.1
`
`on
`IIL2
`
`3"’:
`E
`E’3-=
`
`8 3
`
`3IL!
`
`Figure 5
`
`Screw compressor energy corisnrnprion.
`
`CH—'95—'lIZl-4
`
`Figure 3
`
`Temperature profife of cl perm:-Hy chm-g-ea:
`Iawqempgrunoe sfranfied Ian-.l:_
`
`-
`
`-
`-
`
`-
`
`no ElI:|dl‘l_lI3]‘lal. water ueaunt required that will incrnse
`0051.
`no corrosion inhibitor 1'eqI.I.ired'to protect the rank,
`can be used with conventional as well as Iow-tempera-
`turn: chillers, and
`less expensive per ton-holn than other thermal storage
`systerns.
`
`Series Chilling
`
`Scrlcs chilling is an operating technique that increases
`the capacity ofdisnict cooling networks (Figure 4]. Most ex-
`isting district cooling systems are designed for traditional
`supply ternperaturea in the 40°F to 42"F (4.-4°C lo 5.98}
`range and typically experience return tcrnperatures in the
`52°17 to 56°F (1 1.i"C no l3.3°C] range. In series chilling,
`low-tcmpcranlrc chillers operate in series with conventional
`clnilers, decreasing the supply temperature to 34°F (Il.l°C]
`or less iffreezing-point depressants are used. The increase in
`the cl1illcd—'wa.tI:r Icmperamrc diflbrerrtial frovrn 12°F-14°F
`{_I5.?"C—'i.3°I'.3)
`to 2D"F-25°F [l1.]"C-] 33°C} will almost
`double the capacity of existing disl:ributioI1 piping or, ahcrh
`natively, reduce pumping -power to a fraction. In addition.
`service c.-on be provided to new customers who need chilled
`were: at lemperatttres less Than 40°F (4.4°C)_ The economic
`benefits of series chilling can be significantly enhanced by
`the jnslallation oflow-tcznpemnrre chilled-water storage.
`
`Ammonia Refrigeration
`
`Most older district cooling systm and individual
`buildings are based on commercial he-._a'ting, ventilafing, and
`air-conditioning {HVAC} technology and use packaged cen-
`lrifugol chillcn with CFC rcfi‘l'._gcro.nl5. By cemrasr, most in-
`dustries rei)-ring on refiigeration, such as food processing and
`cold stc rage warehouses, have been using a.rn.rnonia 1'cfi'iger-
`ation for decades.
`
`The growth of the district cooling indoslry, combined
`with the phasing out of CFC refrigerants, has resulted in the
`
`
`
`PAGE 4 of 6
`
`PETITIONER'S EXHIBIT 1027
`
`

`
`
`
`4
`
`lo
`
`data. The high part-compression and part—load efficiencies
`become hicreasiiigly valuable as buildings‘ cooling loads in»
`crfigiy become a fimction of internal heat gains ratlicr
`than wanna arnbient weather, and their cooiing requiiciuems
`extend into periods of cold weather.
`
`Variable-Speed Drives
`
`Variablespeed dzives are not new, but their universal
`and economic applications in district energy systems are.
`W]-1:1-her using electricity, steam, or natural gas, variable-
`speed dfivcs have cootrihutoti to greatly enhance efiiciencics
`in district Energy systems, where the energy demands are
`seasonal and also vary from day to day. ‘Ve.riable~speed
`drives are todayfcornmonlg-'_nsed in the Form ofvariable—[‘re»
`quency drives for electric motors and speed controls for
`steam mrbines and engines.
`The efllciency o-fchiIIeu:l'—water systems in particular can
`be enhanced by the use ofvariable-speed drives. Substantial
`shaft power
`is
`involved in chilled-water pro-duI:I:Ion—
`chiller!-water pumping, compressor power, condenser pump-
`Eng—b-ot the cooling demands vary widely fi-orn hour to
`hour. Significant energy savings can be realized with vari-
`abic-speed drives since the energy consumed is geometri-
`cally proportional to the ‘How rate.
`The savings associated with varia.blo—speod drives are
`nlzalizcd by autumatilally and instantaneously nptirnizziaig the
`drive speed to meet the pi-oducfion requirement ofthe driven
`device. The compressor speed is optirnized to meet the
`chilled-water production rcquizremenls, and pump drives are
`operated to maintain a minimum remote differential pres-
`sure. The continuous adjnscncnts will ensure mat the opera-
`rion is always optimized and that the consumed shaft power
`is miinimized.
`
`Process Automation
`
`District energy systems have benefited much fi-om the
`boom in computer and controls technology in recent years-
`Controls and automation bar-rehecncmpioyedtc improve en-
`ergy efficiency as well as system productivity. Today, fewer
`operators are producing more district energy at higher effi~
`cicney. Autmnation has many applications in district energy
`systems, some of which are outlined below.
`
`Automation for remote operation is of special intcresf,
`since it has the potential to allow the I-Iilization of existing
`equipment ‘without in.I:rernen‘ta] labor additions and thus re-
`duces the capital costs of district energy system develop-
`merit.
`
`W'|ie-re allowed by code, district energy systems served
`by multiple production ‘facilities have been able toopennc
`peaking and back-up plants remotely and in die process irri-
`prove both cficieocy and productivity. Conversely, controls
`tcelmology has enabled other systems to incorporate larger
`customer plants anrithus reduce capital cost expenditures.
`
`Low-cost Distribution Piping
`
`A substantial ofthc cost o-fa new district crt¢1‘g}|'
`system is related to the
`cost of distribution piping.
`Costsavings resulting from new distribution sjrstem technol-
`ogy will significanfly improve the competitive advantage of
`disoict energy.
`.
`The gmdual change to direct ‘curled piping has helped
`reduce the costs of distribution piping. even. l.l1oIJ.gh the pre-
`dominm use of steam as the -distribution medium in the U.S.
`has limited the cost savings here. Dealing with large thermal
`expansion and tin: reqnh-omen: for steam maps and other me»
`chanical devices in the distribution system continues to keep
`the east of st disI:'il:ruticm. high. In Elirnpe, where ri1¢-
`dium-tcn:ip-cmturc hot water is a commonly used distrilwtion
`mediluu, ]:u'gb—qua]ity, inexpensive, massproduoed pip‘i::.“.Ig
`has been predorninantly used since the 19805.
`
`THE ECONOMIC IMPACT OF INNOVATID NS
`
`As outlined above, a large number of teclmieal and op-
`erational innovtaiions have cncttributod to irnptove the com-
`petitiveness Dfdistrict heating and cooling during the last IIIII
`years. These innovations have coincided with institutional,
`erivironsiental, and economic changes in society-—chang.c5
`that by and large have. been favorable for the expansion of
`distzrict heating and cooling.
`issues 113.5
`An increased awareness of cmrironrliental
`opened the public’: eye: to the benefits of district energy and
`has improved me acceptability of district energy as a con-
`cept. At the mme time, stricter regulations have increased
`
`Remote operation. rnonil.nring,redu-cod labor
`
` 1
`
`nails-5
`Ch illcrs
`Pumps
`F-learn Turhirie
`Gas Tnrbin e
`Disuibulion
`Metering
`Peaking. Plants
`
`CH-5':'—1G-4
`
`Elupose
`
`Improved cffieicncy, decreased emissions, monitoring, rcdumrl labor
`Improved cfficicncy, monitoring, reduced labor
`Trnprosl ed efiiciency
`lmpro-red effieicney
`Decreased eornplez-iity. rnunitoririg
`Monitoring. rcdtlccai labor
`Monitoring, accurau:;.r
`
`Spccdcunlrol
`Process
`Pressure. Flow
`Te lemetrics
`Total princess
`
`PAGE 5 of 6
`
`PETITIONER'S EXHIBIT 1027
`
`

`
`
`
`Interestingly, technological advances in district energy
`have often come Eroro other industries. District heating, for
`example, has
`l:-encfitted
`fro-o1
`the
`tlcvelopmertt
`of
`cogcncnrion; this was made possible, in ‘part, by develop-
`ments i:n combustion turbine technology. The defense indus-
`try’: need for liglmveight but pow-erfnii jet engine: was the
`impetus behind this progress.
`District cooling has bcncfitted fi-oro innovations in other
`industries as well. The computer industry has produced so-
`phislitated monitoring devices that have allowed plant oper-
`ators to optimize plant perfonnartce and achieve efficiencies
`never hefore possible.
`Regardless of the source, iiuiovatiou has made Iilistricx
`heating and cooling economical. With the indusn-y‘s ability
`to provide total comfort service, and with growing environ-
`mental concerns, the stage has been set for :1 renaissance in
`the district energ;5r induslzry.
`'
`
`REFERENCES
`
`Andtcpout. 1.3. 1992. Central chilled water plant expansions
`and. the CI-‘C redhgcrant :iss::Ie:—Casc sl:I.'Idies of chilled
`water storage. Proceedings r.f1Iae.»lrsoeio:r'o:: ofHigher
`Education Facilities Ofiicers, T9111 Annual Meeting.
`Washington. DC: A.i'P.FL.
`ASHRAE. 1993. Desigrr gtridefar cool thermal storage. AI-
`Ianta: American Society of Heating, Refi-igerating and
`Air-Conditioning Engineers, Inc.
`.
`Costco, T_R. 1994. District cooling with trigenerate-cl amnio-
`nia -cooling. .-ISHR.-l_E' I'ran.so'::.*.i-on: 100(1).
`CB-&lC. 1939. Tfanrfenr temperature profile: oj'Norrl: Mar-
`qamte High School. Pleiufieicl. IL: Chicago Bridge 3:
`Iron Co.
`
`the environrnenra] performance required of district ergy
`systems. New technical innovations have helped to make
`district heating and cooling more efficient than before. and
`have significantly reduced the potential economic impact of
`stricter environmental regulations. Using recent technology.
`-dislri-::t energy systems use less fuel, electricity, water, and
`other commodities than before. They also produce less emis-
`sioos than any Ctu:I1p£l:l'abl¢ technology-
`_
`'I'I1elow interestrates dl.l1'l.!.‘.|,gtl1I: latte:-part ofthe decade
`provided the means by which to increase spending on capi-
`tal-oive technology, such as district energy. The con:
`i-
`nation of rising electricity rates and falling, interest rates
`provided a powerful incentive to develop new cooling tech-
`nology that, even though capital
`intensive, would prove
`competitive through its high efiiciency.
`DisiriI:t healing and cooling was reinvigorated in the 135:
`few decades and is today accepted as an vironmcntally
`sound and economically attramivc comfort service. The in-
`troduction of itmovafivo technology and the development of
`district cooling has made disuict energy the “right” choice
`for building owners. it is more convenient. less expensive,
`and cleaner than the alternatives. District heating service
`alone leaves the building owner with the task. of spending
`much human and capital resources on cooling; resI:_>urccs that
`in many cases are significantly grater than the ones spent on
`heating. A combined district heating and cooling service is
`the logical choice for a building owner, who can now con-
`centrate on his or her business and avoid operatilig cl1cI'g;}'
`production equipment.
`‘No "one innovation or change can be saidto have caused
`die new vitality in the district aiexggr industry. All innova-
`tions, especially in the district cooling field, have contributed
`to the industry's improved performance and competitiveness.
`in some cases, where district cooling was developed as
`an afteifliought loan existing distri.ct heating system, the dis-
`trict cooling after some time became the main business. Be-
`cause of the many innovations in district cooling and the
`almost unlimited growth potential, the district energy indusn
`try is today increasingly focused on the development of dis-
`trict cooling, Yet, fllrict co-o1'n1g works best, technically and
`as a service, in combination with district heating.
`
`CONCLUSIONS
`
`Technological hmovation has been a. prime co|zI:i1'b1I'tDr
`to the renewed interest in district heating and cooling. It has
`improved the efiiciency and consequently reduced the cost
`of district energy, making it the energy of choice fi'orn an
`economic as well as environmental perspective-
`izinavation has occurred to the largest extent in r.li51:I'ir:t
`cooling, which has, relatively speaking, only recently he-
`come the focus of attention. Trigcoeration, chilled-water
`storage, and other iruiovatioos have reduced operating costs
`significantly, making district cooling. and consequently dis-
`trict energy, highly desirable for the building owner.
`
`CH-95-10-4
`
`
`
`PAGE 6 of 6
`
`PETITIONER'S EXHIBIT 1027