1
Phys.
IV
F ance
9
(1 999) P 3-189
in eg a ion o sola he mal ene gy in a con en iona powe plan :
The Colon sola p ojec
M.
Sil a,
M.
Blanco*
and
V.
Ruiz
G upo de Te modinamica, Escuela Supe io de Ingenie os, Camino de 10s Descub imien os s/n,
4
1098
Se illa, Spain
*
CIEMAT, Pla a o ma Sola de Alme ia, Ca e e a de Senes s/n, Tabe nas, Alme ia, Spain
Abs ac . This pape epo s on he i s phase o he Col6n Sola P ojec , o iginally concei ed as he hyb id
epowe ing o an exis ing he mal powe plan , wi h he addi ion o a gas u bine in a
opping
con igu a ion
in eg a ing he mal ene gy (s eam) p oduced by a sola sys em. Howe e , he p ojec de eloped in a changing
economic en i onmen ,
in
which a new legal s uc u e, s ill incomple e, as o Janua y,
1998
has libe alized he
elec ici y gene a ion ma ke . This o ced he o iginal con igu a ion o be modi ied, esul ing in an all-new combined
cycle wi h sola ene gy in eg a ed in o a Hea Reco e y Boile . Basic plan enginee ing placed special emphasis on he
mos impo an sola componen s (helios a and ecei e ), and
an
economic analysis showed ha he plan is p o i able
unde he assump ions o he analysis. Ne e heless, he ela i ely low
IRR,
as well as he unce ain y o ealiza ion o
some o hose assump ions, made he u ili y pos pone i s decision o build he plan .
Since Janua y 1, 1998, he Spanish powe ma ke has been libe alized. This means ha om now on, i s
ope a ion will be based on a sys em o supply and demand, unde which he exis ing powe demand a any
gi en momen is co e ed by he p oduc ion plan s o e ing he cheapes kwh.
Thus hose powe p oduc ion plan s o uni s ha can o e he cheapes kWh a e he i s o ope a e o
supply he demand, and he e o e, hose ha ha e he bes possibili y o su i ing in he new compe i i e
en i onmen .
Wi hin his new de egula ed amewo k, howe e , a kWh c edi is planned (no ye exp essly enac ed),
o sola o o he enewable ene gy-based p oduc ion.
Such a c edi o elec ici y p oduced om enewable esou ces would p o ide some e y
ad an ageous oppo uni ies o sola he mal echnology, which, when in eg a ed in o hyb id powe plan s,
could be he key o hei lowe ing con en ional gene a ion cos s (because o he mu ual syne gies o he
con en ional and sola echnologies) enabling hem o compe e on he new ma ke .
I he sa is ac o y in eg a ion o sola he mal and con en ional plan s can be demons a ed, i will hen
be he ma ke ha demands he sola echnology, and, accompanied by he ad ances now unde way in
R&D,
will lead o i s wide-scale u iliza ioa in he Medi e anean basin and elsewhe e.
This demons a ion is one o he main objec i es o he Colon Sola P ojec , which is suppo ed by he
The mie p og am o he Eu opean Commission. The ecen ly comple ed i s phase o his p ojec in ol ed
9 o ganiza ions (u ili ies, equipmen manu ac u z s, enginee ing i ms and esea ch cen e s) om
4
di e en
Eu opean coun ies, led by one o he u ili ies, Se illana de Elec icidad. This is one o he dis inc i e
aspec s o he p ojec compa ed o o he sola ene gy p ojec s, since he leade is a inal use o he
echnology, ins ead o an
R&D
ins i u ion.
A icle published online by EDP Sciences and a ailable a h p://dx.doi.o g/10.1051/jp4:1999328
JOURNAL
DE
PHYSIQUE
IV
2.
BACKGROUND
Fi s concei ed
as
hyb id epowe ing o an exis ing he mal powe plan wi h a
opping
con igu a ion based
on he exis ing plan , an added gas u bine and an in eg a ed sola ield, he Col6n Sola P ojec employs he
SOLGAS concep [I], as de eloped in he APAS SOLGAS P ojec [2]. The SOLGAS concep pos ula es
hyb idiza ion o high-e iciency powe plan s (combined B ay on-Rankine cycle, cogene a ion cycles) and
he use o Cen al Recei e Sys ems (CRS) as a ealis ic and iable pa h owa ds ma ke able sola he mal
ene gy applica ions.
Hyb idiza ion has adi ionally been conside ed a means o o e ide he mos signi ican d awbacks o
sola ene gy, which is in e mi en and andom, o elec ici y p oduc ion. This poin o iew concei es he
ossilpa
o he hyb id powe plan p ima ily as auxilia y suppo o adap p oduc ion o he demand when
sola ene gy is una ailable o insu icien .
Howe e , despi e he conside able p og ess in sola echnology in ecen yea s, none o he p oposals o
build sola (hyb id o s and-alone) powe plan s has succeeded, wi h he ema kable excep ion o he SEGS
plan s in Cali o nia. Sola he mal echnology seems o be apped in a
icious ci cle
[2] impeding ma ke
access.
The concep o he
Op imized Powe Plan ,
which is he co e o he SOLGAS p oposal, is a ealis ic,
inno a i e app oach o hyb idiza ion, emphasizing iabili y in he eal-wo ld scena io, in which a la ge
sola ac ion o he hyb id plan is no longe ele an . In he p esen si ua ion, any p og ess in ma ke ing
sola he mal echnology makes sense. In he same ega d, he SOLGAS concep ad oca es he use o
p o en, eliable componen s o he Cen al Recei e Sys em (CRS) echnology, in o de o con ince
po en ial use s (u ili ies) and inancial ins i u ions ha he sola he mal (and mo e speci ically, CRS)
echnology is no imma u e. This does no imply ha o he mo e ambi ious schemes ha ake ull ad an age
o sola adia ion's po en ial o high exe gy a e o go en o may no be easible in he u u e.
The sola sys em, which s a s up a sligh ly unde he sa u a ion poin , is used o boil wa e , wi h he
ollowing ad an ages:
a) Fo he hea exchange ( he "hea eco e y" uni ):
I lessens he empe a u e d op be ween he ho gases lea ing he u bine and he coolan in he Rankine
cycle.
I all bu elimina es he hea -exchange pinch.
I does no was e high- empe a u e gas in he ene gy-guzzling e apo a i e p ocess.
b) Fo he sola sys em:
I alle ia es ope a ing condi ions by elimina ing high empe a u es and ins abili ies associa ed wi h
supe hea ing.
I inc eases he he mal e iciency o collec ion by aking ad an age o wo-phase hea ans e
h oughou mos o o he en i e ecei e .
I elimina es he need o s o age.
I signi ican ly educes plan s a up ime.
c) Fo he o e all sys em:
I enables all o he collec ed sola ene gy o be used as a subs i u e o he ossil uel.
The sola con ibu ion jus i ies a modes amoun o combus ion in he Rankine cycle, o main ain
boiling du ing cloudy pe iods o ea ly and la e in he day
3.
PROJECT ORGANIZATION
The i s phase o he p ojec in ol ed
10
o ganiza ions led by one o he u ili ies, Se illana de Elec icidad.
This is one o he dis inc i e aspec s o he p ojec compa ed o o he sola ene gy p ojec s, since he leade
is a inal use o he echnology, ins ead o an R&D ins i u ion. The pa icipan s we e:
STCT
9 P 3-191
U ili ies: Se illana de Elec icidad, ENDESA (Spain), EDP (Po ugal)
Manu ac u e s
/
Enginee ing i ms: ABB S all (Sweden), INABENSA, BWE (Spain), PROET (Po ugal)
Resea ch ins i u ions: CIEMAT, AICIA (Spain), DLR (Ge many).
The h ee g oups we e coo dina ed by Se illana.
4.
RESULTS
As a consequence o he changes in he legal amewo k since he p ojec was i s p oposed (June, 1996),
he ini ial scheme ( opping) p o ed economically un easible in he new elec ici y gene a ion scena io. The
plan con igu a ion e ol ed du ing p ojec de elopmen in o a hyb id powe plan in which he powe block
is a comple ely new combined cycle (Figu e
1)
o which only some auxilia y sys ems o he exis ing powe
plan a e eused.
Na u al
Ga
The ABB GTX-100, 43-MW
nominal powe gas u bine wo ks
a ull load unde no mal ope a ing
condi ions. The dual p essu e Hea
Reco e y Reco e y Boile , has wo
Boile addi ional bu ne s o con ol he
low o s eam o he s eam u bine
in di e en ope a ing modes and in
he e en o sudden changes in
sola adia ion. S eam Tu bine
design powe is 30-MW, wi h a
s eam low o 78.8 /h a 510°C in
he high-p essu e (99.8 ba ) sec ion
and
15.5
lh
a 181°C in he low-
S eam Tu bine p essu e (2.76 ba ) sec ion.
Table shows he main
Figu e
1.
Colon Sola plan inal con igu a ion
pe o mance pa ame e s o he
Colon Sola Plan .
Table
1.
Main pe o mance pa ame e s o he Colon Sola Plan
The Colbn Sola powe plan is loca ed in Huel a (Sou he n Spain) whe e annual i adiance is 2063
kWh/m2. The sola pa is a Cen al Recei e Sys em wi h a collec o subsys em o 489 helios a s (each
wi h a 70-m2 e lec i e su ace) and a 21.8 MW,,, s eam ca i y ecei e (powe o luid unde design
condi ions), on a owe a a heigh o 109 m. The land allo ed o he p ojec is app oxima ely iangula ,
bu non-symme ical, c ossed by powe lines and supply duc s. Because o hese cha ac e is ics, he
helios a ield (Figu e
2)
and he lux on he abso be a e no symme ical and he owe is alle han usual.
Howe e , he sola sys em pe o mance pa ame e s a e no e y di e en om hose o a symme ical ield
and ecei e beha io is una ec ed.
Wi h Sun
28.4
42.7
71.1
70.4
114.8
61.3
Wi hou Sun
20.0
42.7
62.7
60.0
114.8
54.0
S eam Tu bi ie Powe
Gas Tu bine Powe
To al G oss Powe
To al Ne Powe
Fuel Consump ion
Ne E iciency
Uni
MW
MW
MW
MW
MW s/LHP
%
s/LHP
P 3-192
JOURNAL
DE
PHYSIQUE
IV
Figu e
2.
Colon Sola helios a ield
The main cha ac e is ics and pe o mance pa ame e s o
he
sola sys em a e p esen ed in Table 2.
STCT
9
P 3-193
Table
2.
Main cha ac e is ics and pe o mance pa ame e s o he sola sys em
The mos signi ican componen s o he sola plan , helios a s and ecei e enginee ing ha e been
wo ked ou in g ea de ail.
Powe o luid (desipn poin )
.Helios a ield e icienc (desim poin )
Recei e e icienc (design ooin )
Sola s s em e iciency (sola o he mal, design ooin )
Ene gy collec ed by luid (excludins ope a ional losses. ea l )
Helios a ield e icienc ( ea ly)
Sola sys em e ciency (yea ly)
The non-symme ical shape o he land a ailable (Figu e 2) and he es ic ions on i s use made
necessa y a new helios a design ha would make he bes possible use o he land.
21.8
MW
0.805
0.935
0.753
43.5
GWh
0.747
0.619
A
helios a p o o ype wi h 21 3-x-1.1-m ace s, 70-mZ e lec i e su ace and no cen al gap has been
designed and buil and es ed a he Pla a o ma sola de Alme ia. Tes esul s show ha he helios a mee s
he speci ica ions ( o al e o
I
2.9m ad) wi h low powe
consump ion.
The sa u a ed s eam ecei e
has been designed o maximum
eliabili y and pe o mance.
The mal and s ess analyses show
ha hese objec i es ha e been
achie ed wi h a simple, du able
design. The ecei e demons a es
excellen e iciency (abo e o
close o 90% in an ope a ing ange
up o 20% pa load) and due o
wo-phase luid condi ions du ing
mos o i s ansi h ough he
ecei e ubes, limi ed empe a u e
g adien s.
Figu e
3.
F on iew o he Colon Sola helios a

JOURNAL
DE
PHYSIQUE
IV
5.
ECONOMIC AND PROFITABILITY ANALYSIS
The p ojec budge was based on o e s om quali ied supplie s. Acco ding o hese o e s, he o al Col6n
Sola Plan in es men will be 7933 Mp as., 36% o which co esponds o he sola pa .
Among o he hypo heses, he p o i abili y analysis assumes ha subsidies om he EU and o he will
be 2417 Mp as and c edi (p ice suppo ) o he elec ici y o sola o igin will be 15
p as/kWh. Elec ici y
sales and ope a ing cos s o a 15-yea pe iod unde he new egula ions we e es ima ed using
a
model o
ha gene a ion scena io. Acco ding o his model, he plan is p o i able, wi h
IRR
o 8.36% and NPV o
1085 Mp as, assuming a 12%.discoun a e.
Howe e , because o he unce ain y ega ding he abo e men ioned assump ions (enac men o he law
egula ing subsidies o enewable elec ici y is s ill in p ocess) and he ac ha he
IRR
is lowe han ha
equi ed by he u ili y o new in es men s led o he u ili y's decision o pos pone he decision o build he
plan .
6.
CONCLUSIONS
The new de egula ed legal amewo k o he powe gene a ion ma ke subs an ially modi ied some o he
p emises ha led o he o iginal Coldn Sola p oposal, equi ing addi ional e o o adap o his changing
en i onmen , while main aining he quali y o he p ojec and keeping, in so a as possible, on schedule.
The mos ele an conclusions o his phase o he p ojec a e he ollowing:
The o iginal plan con igu a ion ( epowe ing he C is dbal Coldn The mal Powe Plan Uni
I
wi h a
opping scheme), was disca ed in a o o a con igu a ion based on a
new combined cycle, in which
sola gene a ed s eam is in eg a ed in o he Hea Reco e y Boile ).
This new con igu a ion mee s he
echnical and economic c i e ia o iabili y in he compe i i e en i onmen .
Economic analysis o he new con igu a ion showed ha he
Col6n Sola p ojec is iable in he new
compe i i e en i onmen ,
p o ided ha he hypo heses used in he analysis (c edi o sola powe
p oduc ion, subsidies om he
UE
and o he inancing bodies, p ices o na u al gas and elec ici y) a e
ealized, in which case, Coldn Sola plan income would be g ea e han i s ope a ing cos s.
Howe e , p ojec e u ns
(IRR
=
8.36%) a e s ill less han equi ed by he u ili y o new in es men s.
This, in iew o he unce ain y ega ding some o he hypo heses o he economic analysis, led he
u ili ies o
pos pone hei decision o build he plan un il he unce ain ies a e esol ed.
When designing he main plan sys ems, special emphasis was placed on he non-con en ional
equipmen , ha is, sola ecei e , helios a s and hea eco e y boile ecei ed.
Comme cial quo a ions o sys em componen s ecei ed om expe ienced manu ac u ing and
enginee ing i ms a e no only a eliable basis o a plan cons uc ion budge , bu also show ha he e is
a sound echnological base in he indus y, which a i ms he ma u i y o he Cen al Recei e Sys em
echnology.
Bibliog aphy
[I]
M.
Blanco and
V.
Ruiz. The Solgas P ojec . P oceeding o he Eu opean Con e ence and Con ac o s
Mee ing. Venice, I aly. No embe , 1995.
[2] M. Blanco (coo dinado ) e al . SOLGAS P ojec ,: Hyb id Combined Cycle Cogene a ion Plan Based
on Cen al Recei e Technology. Final Repo . Con a c APAS RENA-CT94-0043. Se illa, 1996.