Outlook on Concentrating Solar Power

Slide 1

Outlook on Concentrating Solar Power

Manuel RomeroDirectorRenewable Energy DivisionCIEMATAvda. Complutense 22 28040 Madrid

Internacional Symposium:Energy and SustainabilityMadrid, June 16-17, 2008

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Outlook Outlook onon CSPCSP

What does CSP mean?.What do they say about CSP?:

ThermodynamicsEconomyContexto europeo, regional y mundialEmployment

Projects under developmentRole of R&D

Solar towersParabolic troughs

Conclusions

Structure:

Slide 3

OPTICAL CONCENTRATOROPTICAL CONCENTRATOR

RECEIVERRECEIVER

FOSSIL BACKUPFOSSIL BACKUP

HEAT HEAT STORAGESTORAGE

COLD POINTCOLD POINT

HOT HOT POINTPOINT

WW

OPTICAL CONCENTRATOROPTICAL CONCENTRATOROPTICAL CONCENTRATOROPTICAL CONCENTRATOR

RECEIVERRECEIVERRECEIVERRECEIVER

FOSSIL BACKUPFOSSIL BACKUPFOSSIL BACKUPFOSSIL BACKUP



COLD POINTCOLD POINTCOLD POINTCOLD POINT

HOT HOT POINTPOINTHOT HOT

POINTPOINT

WWWW

Solar Solar ThermalThermal PowerPower PlantsPlants: : AmbitionAmbition ofof bulkbulk powerpower productionproduction

Unique integrability into conventional thermal plantsWith thermal storage or fossil fuel backup solar thermal plants can provide firm capacity without the need of separate backup power plants and without stochastic perturbations of the grid.Solar thermal can supply peak power in summerly heat periods when hydro and wind are scarce.Application to the MW scale.

Solar time

Fromstorage Solar direct

supply

To storage

From storage

Fixed power

Ther

mal

ener

gyto

turb

ine

Solar time

Fossilbackup Solar direct

supply

Fossil backup

Fixed power

Ther

mal

ener

gyto

turb

ine

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Solar Receiver

Heliostats

Absorber Tube

Pipe with thermal fluid

Curved mirror

Receiver / Engine

Reflector

Central Receiver

Parabolic Trough

Dish/Engine

Linear Fresnel

Absorber tube andreconcentrator

Curvedmirror

Solar Receiver

Heliostats

Solar Receiver

Heliostats

Absorber Tube

Pipe with thermal fluid

Curved mirror

Receiver / Engine

Reflector

Receiver / Engine

Reflector

Central Receiver

Parabolic Trough

Dish/Engine

Linear Fresnel

Absorber tube andreconcentrator

Curvedmirror

Solar thermal power plants

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Are Are CSPsCSPs Competitive ?Competitive ?

Who

lesa

leP

ower

Ret

ail

Pow

er

10 20 30 40 50Power Generation Costs in USD Cents/ kWh

Small Hydro

Solar Photovoltaics

Concentrating Solar

Biomass

Geothermal

Wind

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• Up to 15 GW until 2020 at 5- 8 cents/kWh

1980 1990 2000 2010 2020

Sola

r Gen

erat

ion

Cos

t in

Euro

Cen

ts/k

Wh

15

25

50

8

100

SpanishPremiums2000 kWh/m²

SEGS III-VII

R&DDemo

Grants

IEA SSPS, CESA-I

SOLAR ONE

SOLAR TWO

CaliforniaPremiums

2700kWh/m²a

SEGS-ISEGS- II

SEGS VIII-IX

GreenPricing

R&D andDEMOPhase

CaliforniaSubsidized

Markets

EuropeanSubsidized

Markets

GreenPower

Markets

AndaSol 1

AndaSol N

Solar TresPS10 Next Generation

Technology

New Market Entry

Market Introduction of Solar Thermal Power Still in the learning curve

Europe: New market entry

Slide 9

Slide 10

Trans- Mediterranean Renewable Energy CooperationTrans- Mediterranean Renewable Energy Cooperation

HVDC networks

Ain Beni Mathar

Hassi R’mel

Slide 12

CSP worlwide initiatives

SourceSource: : AbengoaAbengoa SolarSolar

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CSP worlwide initiatives

Slide 14

Slide 15

50 MW

500 MW

500 MW

50 MW

50 MW

150 MW

500 MW

350 MW

At the end of 2007 more than 50 CSP projects with about 2150 MW have been registered by the Ministry of Industry

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TwoTwo decadesdecades ofof continuouscontinuous R&DR&D

EUROTROUGH, DISS, INDITEP, EURODISH, SOLAIR, EUROTROUGH, DISS, INDITEP, EURODISH, SOLAIR, SOLGATE, SOLHYCO, DISTORSOLGATE, SOLHYCO, DISTOR

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40

80

50

60

100

2005 2010 2015 2020 2025 Year

70

Prod

uctio

n co

st

90

ScalingScaling upup15%15%

R+DR+D60%60%

MarketMarket seriesseries25%25%

Impact of innovation on cost reduction

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Solar towers today: Early commercial plants

11.0MWe

Heliostat Field

Solar receiver

Steam Storage System

40 bar, 250ºC»Steam

Drum

Turbine

Heliostat Field

Steam Storage System

Steam

Condenser0,06 bar, 50ºC

SteamDrum

Turbine

≈

Em p lacem en t

Nom inal Pow er Tow er Heigh t

Receiver Tech no logy Receiver Geom et ry

Heliostat s Therm al Sto rage Techno logy

Therm al Sto rage Cap acit y Steam Cycle

Elect ric Gen erat ion Land

A nnual Elect ricit y Product ion

Gen e r a l D escr ip t io n San lúcar M . (Sevilla), Lat 37 .4º, Lon 6 .23 º 11 .02M W e 100mSatu rated Steam Cavit y180 º, 4 Pannels 5m x 12 m 624 @ 121m 2 W ater/Steam 15M W h, 50m in @ 50% Rate 40bar 250 ºC, 2 Pressu res 6 .3kV, 50Hz -> 66kV, 50Hz 60Has 23 .0GW h

ABENGOA SOLAR

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PS10: Heliostats aimingABENGOA SOLAR

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PS10: Concentrated beamABENGOA SOLAR

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PS20 and PS10 in Seville (Spain) ABENGOA SOLAR

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Solar Towers Today: Early commercial plants

This project is partially supported by the European Commission (Contract No. NNE5/2001/369), through an European Consortium formed by SENER, CIEMAT, ALSTOM-SIEMENS, SAINT GOBAIN and GHERSA.

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Heliostats: Can innovations lower costs?

Ganged heliostats (>400 m2) Megahelio with carousel (>200 m2)Structurally integrated reflectors (GFRP, hollow extruded polymers)Wireless/PV autonomous heliostat

DLR Abengoa

30% cost reduction through:

PSA-CIEMAT

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Solar receiver: Reliable black-body is the key

Operational range for different solar receivers (Source: A. Kribus)

0

500

1000

1500

2000

0 20 40 60 80 100 120 140 160

Pressure (bar)

Tem

pera

ture

(ºC

)

Volu-metric

Futuredevelopments

Tubular cavity

Tubular external

Trough linear

Water-steam need to develop super-heating at high solar flux.Volumetric should improve volumetric effect without penalizing fluid-dynamics and flux profile flexibility.Molten salt should demonstrate long-term availability and increase peak fluxParticle receivers and falling films still to pass feasibility phase.All should accumulate operational experience and long-term endurance tests.

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Receivers: More compact, durable and efficient (Efficiency > 85%)

SENER-CIEMAT

0 1000 2000 3000

Cur

rent

Nex

tge

nera

tion

Peak flux on aperture (kW/m2)

VolumetricMolten saltWater-steam

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Heat storage: Essential to Heat storage: Essential to become become dispatchabledispatchable

• 2-tank molten salt storage for central receiver plants.

• Thermocline pebble bed.• Sand or mobile solid

material for air and particle receivers

• PCM/ fins storage for saturated water/steam

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Optimizing solar integration

Hybrid Solar/fossil

Biomass

Modularity

New cycles

Hydrogen

air in

550°C

900°C

heat exchangerfor cogeneration

recuperator

combustor

receiver

solar energy

300°C

air in

550°C

900°C

heat exchangerfor cogeneration

recuperator

combustor

receiver

solar energy

300°C

Project: SOLHYCO

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Diagram of an HTF (Heat Transfer Fluid) Solar Power Plant

295 ºC Oil

395 ºC Oil

Steamgenerator

. Deaerator

ReheaterOil expansion vessel

Steam turbine

CondenserG

Sol

ar F

ield

Steamgenerator

. Deaerator

ReheaterOil expansion vessel

Steam turbine

Condenser

Preheater

Superheated Steam (104bar/380ºC)

ReheatedReheated Steam 17bar/371ºC

G

Sol

ar F

ield

Molten salts(hot tank)

Molten salts(cold tank)

Molten salts(hot tank)

Molten salts(cold tank)

Today's European Trough TechnologyToday's European Trough Technology

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•Municipality of Aldeire (Granada).•Under construction.•Start Date: 3Q 2008.•Infrastructures of evacuation: October 2007.•Line and SE 66 kV: October 2007.•Satellite Plant of Gas: October 2007.

AndasolAndasol 1: 1: UnderUnder constructionconstruction

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AndasolAndasol 1: 1: PowerPower blockblock

Two storage tanks (ø= 36 m, h=14 m)• Storage capacity (h): 7,5h @ 50 MW• Molten salts: 28,000 Metric Tons/• Melting temperature: 221º C• Working range: 291º C - 384º C

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Current R+D activities related to Trough Technology

TomorrowTomorrow´́s Trough Technologys Trough Technology

New receiver tube designs

New support structure designs

New solar reflectors

New working fluids for the solar field

New thermal storage systems

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Current R+D activities related to Trough Current R+D activities related to Trough TechnologyTechnology

Current absorbers glass-to-metal weld

Steel pipe with selective coatingGlass cover

'Getter' to keep and maintainExpansion bellows

Glass pin to evacuate the airVacuum between the glass coverand the steel pipe

Glass-to-Metal weld

the vacuum

Solel design Schott design

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New receiver tube designs

New selective coatings and anti-reflecting filmsNew selective coatings with lower emissivity

(ε<0,1 at 400ºC) and better thermal durability havealready been

developed in laboratories. An industrial process for mass production is still pending

The mid-term outcome of current R+D activities related to new receiver tubes will probably bebetter performance at a slightly lower cost and availability of cheaper products for T< 300ºC

New evacuated receiver tube designs with glass-to-metal weldsThe new receiver tube designs will be very similar to the Schott and SOLEL designs. The mainbenefit from these new designs will be a larger offer that will ensure reasonable prices

Partially-evacuated receiver pipes without glass-to-metal weldingGlass-to-metal welding will be replaced by a mechanical seal. The main benefit of these receiver tubes is their superior durability and reliability at a price similar to evacuated receivers

Low-cost non-evacuated receiver pipesGlass-to-metal welds will be replaced by a simple seal and the selective coating will be replaced by black thermal paint. Though thermal losses will be higher than in evacuated tubes, the pricewill be much lower and they could be cost-effective for temperatures up to 300ºC

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New working fluids for parabolic-trough collectorsMajor disadvantages of current HTF technology are:

limited maximum steam temperature (∼380ºC)pollution and fire hazards

Three new working fluids are being investigated to replace thermal oil and thus overcome its limitations:

molten saltsdirect steam generationgas

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New thermal storage systemsThere are three R&D lines at present, related to:

Two-tank molten-salt storage systems seem to be the best short-to-medium-termoption for HTF plants if reliability is confirmed by first operating results. PCM and concrete thermal storage systems seem feasible for DSG plants in the medium to long term.

Sensible heat with molten salt (< 580ºC)Though huge two-tank molten-salt storage systems (1GWht) are being implemented in large parabolic-trough solar power plants, this technology has not yet been validated for this size. R&D is still requiredto investigate the long-term performance and reliability of big systems.

Latent heat with molten salt (phase change) (< 320ºC)DSG solar plants require thermal storage systems using phase-change materials (PCM). Severaloptions for PCM storage systems are under study at present (DISTOR project) and a 200kWht prototype is also being evaluated at the PSA.

Sensible heat storage with concreteThe goal of these R&D activities is to achieve a specific cost of 20 €/kWh of capacity. A 2x350 kWh prototype has been tested at the PSA with encouraging results.

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New thermal storage systems

200 kWht

prototype of PCM storagesystem designed and manufactured in the DISTOR project

2x350 kWh prototype of concrete storage system installed and tested at the PSA

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CONCLUSIONSCONCLUSIONS

CSP introduces solar energy to high-value marketson high temperature processes, providing highcapacity and dispatchability.Solar thermal power plants offer a wide portfolio ofintegration options with heat storage or hybridoperation for massive production of electricity. First commercial projects already going on in Spainand elsewhere.STPP may integrate North-South Mediterraneanelectrical networks

CSP:

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ConclusionsConclusions

Solar towers are nowadays on the verge of commercialization.

Early commercial plants (PS10, PS20, Almadén 20 and Solar Tres) will focus further R&D and will provide updated information on costs, efficiencies and O&M. These plants should be used to establish on- site diagnostic methodologies for concentrators and receivers.

Heliostats are today mature in terms of performance but still require substantial cost reduction.

Receivers need priority work on scaling-up, long-term endurance tests and more compact designs.

Better integration into hybrid schemes, biomass and/or higher efficiency cycles is required.

Solar towers:

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ConclusionsConclusions

More economical collector designs will be available in short-term with easy-to-implement quality control procedures

Receiver pipes designed to meet different requirements will be available in mid term (e.g., non-evacuated low-cost receivers for T<300ºC, semi-evacuated receivers for T< 400ºC)

The use of two-tank molten-salt storage systems in mid-to-long-term still strongly depends on first plant O&M results. PCM and concrete-based thermal storage systems will be available in mid-term (>6 years)

The oil of HTF technology will be replaced by other working fluids. The best option can not be found without testing it in a pre-commercial solar plant under real O&M conditions.

Parabolic troughs:

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Outlook on Concentrating Solar Power