Small Solar Thermal Power Systems/ Pequeños Sistemas

para Centrales Solares Termoeléctricas

Jornada de difusión técnica

Madrid, 1 de julio de 2010

UNION EUROPEAFONDO SOCIAL EUROPEO

• Mission:• To promote the development of renewable

energies.• To promote the development of clean energy

technologies having none or minimum environmental impact.

• Research topics:• Solar energy (high flux/high temperature).• Sustainable fuels: biofuels, wastes, hydrogen.• Energy storage.• Smart energy networks.• Efficient end-use of energy• CO2 valorisation

• 40 Researchers (18 PhD; 16 from foreign R&D Centers)

IMDEA Energía

Development of efficient and cost-effective high temperature technologies and applications with special emphasis on Concentrating Solar Power Systems and production of Solar Fuels and Chemicals.

Objectives

Modular concepts with minimum environmental impact

Advanced thermal fluids for high temperature applications and energy storage

Solar receivers and reactors Solar concentration optics High flux/high temperature characterization

techniques and simulation tools Efficient integration schemes into power

conversion systems

Solar-driven high temperature production of H2 /Chemicals

R&D lines

High Temperature Processes Unit

Source: Photon International (December 2009)- Spain: 831 MW grid-connected by December 2010 and permits assigned for 2,5 GW by 2013.- USA: Near- to medium-term CSP pipeline over 10 GW,

with 4.5 GW to break ground by the end of 2010.

CSP in the world

Impact of 1-2¢ adderfor green power

Conventional Technology

for Peaking or Intermediate Power (IEA market assumptions)

Initial SEGS Plants

Concentrating Solar Power:

Cost and Availability

Larger SEGS Plants

O&M Cost Reduction at SEGS Plants

Scale-up and

early experience

AdvancedTechnology

Large-scale deployment

• Future costs depend on many things– technology progress– production rates and continuity– political, economic, and financial issues– market needs and acceptance

Scale-up and

early

experienceAdvanced

Technology Large-scale deployment

Commercial projects use technologies of parabolic troughs with low concentration in two dimensions and linear focus, or systems of central tower and heliostat fields, operating with thermal fluids at relatively modest temperatures, below 400 ºC .

The most immediate consequences of these conservative designs are:

the use of systems with efficiencies below 20% nominal in the conversion of direct solar radiation to electricity,

the tight limitation in the use of efficient energy storage systems,

the high water consumption and land extension due to the inefficiency of the integration with the power block,

the lack of rational schemes for their integration in distributed generation architectures and

the limitation to reach the temperatures needed for the generation processes following thermochemical routes of solar fuels like hydrogen.

Limitations of first-generation CSP

Extresol 1 and 2 (ACS/Cobra)

PS10 and PS20 (Abengoa Solar)

40

80

50

60

100

2005 2010 2015 2020 2025 Year

70

Pro

du

cti

on

cost 90

Scaling up15%

R+D60%

Market series25%

Impact of innovation on cost reduction

· hybrid gas combined cycle

coal, fuel oil, or gas steam cycle

Dispatchability: hybridization with gas or liquid

fuels for extended Stirling or Brayton engine operation

thermal storage for peaking, load following, or extended operation

Concentrating Solar Power:

Applications and Features

Manufacturing:

Relatively conventional technology (glass, steel, gears, heat engines, etc.) allows rapid manufacturing scale-up, low risk, conventional maintenance

Distributed Power• distributed, on-grid (e.g., line support)• stand-alone, off-grid (e.g., water pumping,

village electrification)

kW's to MW’s

Dispatchable Power• utility peak and intermediate• high-value, green markets

10's to 100’s of MW's

Aprovechamiento Térmico de la Energía Solar de manera Gestionable, Eficiente y Modular en Sistemas de Alta Concentración

Tem

pera

tura

Receptores Aceite

ReceptoresAgua/vapor

Receptores Sodio

Receptores Sales nitrosas

Receptores metálicos aire

Actualidad

Motores Stirling solarizados

Receptores cerámicos

Baja presión Alta temperatura

Receptores cerámicos

Alta presión Alta temperatura Receptores

Partículas sólidas

Conceptos tecnológicos ACTUALES Conceptos tecnológicos AVANZADOS

• Calentamiento de vapor

• Ciclo Rankine• Calentamiento de vapor

• Calentamiento aire• Ciclo Rankine• Calentamiento de vapor

• Ciclo Brayton• Precalentamiento aire

• Disco Stirling

• Calentamiento aire

• Ciclo Brayton• Calentamiento aire

• Combustibles y química• Ciclo Brayton• Calentamiento aire

500

ºC10

00 ºC

1500

ºC

SOLGEMAC

TODAY Conservative first-generation schemes

SOLGEMAC Efficiency (high-temperature/high-flux) Dispatchability (storage/hybrid) Modularity (small size) Environmental impact (water) Solar fuels

SOLGEMAC(Imdea Energía Coord.)

A.3. ENERGY STORAGE FOR DISTRIBUTED GENERATION CONCENTRATING SOLAR SYSTEMS.

A.3.1.Hydrogen production with thermochemical cyclesA.3.2. Hydrogen storage with MOF-type materiales.A.3.3. Electrochemical storageA.3.4. End-use of hydrogen in microturbines

URJC (Coord.)CIEMAT-DQCIEMAT-SSCImdea EnergíaUAMINTAHynergreen

A.1. MODULAR CONCENTRATING SYSTEMS

A.1.1. Systemas dish/StirlingA.1.2. Multitower Modular ArraysA.1.3. Solarization of gas microturbines

Imdea Energía (Coord.)

INTA

CIEMAT-SSC

TORRESOL

A.2. SOLAR RECEIVERS/REACTORS FOR HIGH FLUX/HIGH TEMPERATURES.

A.2.1. Volumetric receivers with metallic absorbersA.2.2. Volumetric receivers with ceramic absorbersA.2.3. Particle receiversA.2.4. Materials

CIEMAT-SSC (Coord.)Imdea EnergíaURJCTORRESOLHynergreen

A4. INTEGRATIONA.4.1. Comparison of technologiesA.4.2. Integration schemesA.4.3. LCA and impact

INTA (Coord.)URJC, Imdea Energía, CIEMAT-SSC, CIEMAT-DQ, TORRESOL, Hynergreen

MODULARITY DISPATCHABILITYEFFICIENCY

INTEGRATION

STEPS TO SCALING-UP SOLAR CSP & CSFC

30-50 kWSolar Furnace

1-100 MW Central Receiver System

100-500 kWMini-tower

1-5 kWSolar Simulator

Discos parabólicos

Motor solar de Augustin Mouchot en la exposición de

Paris de 1861 ParisDiscos-Stirling Eurodish en la Plataforma Solar de Almería

Motores Stirling avanzados están mostrando altas eficiencias y durabilidades

Varios diseños de disco y de receptor han demostrado la alta eficiencia necesaria para sistemas comerciales

La durabilidad del receptor aún necesita mejorarse

El coste del disco colector/concentrador es crítico para dar paso a las primeras producciones comerciales.

Discos Parabólicos con generador Stirling:

Estado de la Tecnología

STMSolo

Expectations for Cost Degression

PrototypeStuttgart

1989

DISTAL 11991

DISTAL 21995

EuroDish2000/2001

100/Year 1000/Year 3000/Year 10000/Year

0

25

50

75

100

125

150

175

200

225

Inve

stm

ent

cos

t in

k€

Transport, AssemblyConcentrator DrivesStirlingmotorControlTurntableFoundation

Pequeños sistemas de receptor central

Multitower arrays

Configuraciones multitorrePequeños campos con pequeños helióstatos

ACTF de Georgia

• Planta construida en Italia y montada en los EEUU en el año 1977 en el Instituto Tecnológico de Georgia (Advanced Component Test Facility)

• 550 helióstatos

• Potencia térmica 400 kW.

• Campo octogonal y torre central (22,8 m)

• Foco rectangular de 2,44 m.

• Espejos con seguimiento polar y tracking colectivo.

• Planta construida en Italia y montada en los EEUU en el año 1977 en el Instituto Tecnológico de Georgia (Advanced Component Test Facility)

• 550 helióstatos

• Potencia térmica 400 kW.

• Campo octogonal y torre central (22,8 m)

• Foco rectangular de 2,44 m.

• Espejos con seguimiento polar y tracking colectivo.

Mini-campos con mini-helióstatos agrupados: Recordando al Prof. Francia

Sistemas modulares multitorre

Comparison of Solar Power Technologies with respect to Integration in the Urban Environment

P. Schramek, D.R. Mills and W. Lang

• Origin: In 1972 by US HUD. Related to Total Energy Systems, Power Islands, District Heating, Energy Cascade and Cogeneration

• Distributed Utility structure for large residential, commercial or institutional building complexes.

• Typical size: 300-1,000 dwelling units• Reduction of transmission and distribution costs• Modular track of demand and spread construction costs

over time• Maximum utilization about 4,500 hours • Use of single-cycle high efficiency gas turbines plus waste

heat applications like district heating, cooling, desalination or water treatment

• Increment of solar share to 50 %

Advantages of the MIUS concept

The keys for CRS in MIUS

• Find a niche of size (a few MWe)

• Find modular small CRS design

• Competitive investment cost

• Perform with high efficiencies

Domestic and auxiliaryelectricity

Compressionair-conditioning

Fuel

Air

Absorptionchiller

Hot water

Auxiliary boilerFuel

Water

Space heating

Domestic hot waterSteam

Water

Exhaust gases

Hot gases

SOLAR TOWER

60,526 GJ 5.50 GWhe

5.29 GWhe

0.21 GWhe

12,000 GJ

22,000 GJ

2,690 GJ

13,280 GJ

Rejected heat22,793 GWh

11,023 GJ

7,965 GJ

Wasted4,252 GJ

14,690 GJ

INTEGRATION OF CRS INTO MIUS STRUCTURE

Example of a 450-unit apartment complex in Spain

0

200

400

600

800

1000

1200

1400

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Solar Time (h)

Po

wer

Dem

and

(kW

e)

October

November

December

January

February

March

april

may

June

July

August

September

MIUS Solar Tower: Application to a shopping center

- Stable demand

- 85 % during day-time

- High consumption at peak periods

- Monthly differences between 800-1,300 kW

- Demand increase between June and October.

- Peaks in July and Christmas

Operation strategy:

- Night-time: Grid

- From 6:00 to 20:00 solar hybrid turbine in power island mode

Demand from 6 to 20 h: 4,348 MWe and 18,890 MWth

Proposal of a small-size tower plant

Small tower and heliostats that reduce visual impact and achieve higher field efficiencies (up to 4% more than large area heliostats).

Air as heat transfer media in a pressurized volumetric receiver (3.4 MWth outlet).

Use of an efficient (39.5 %) small solar-gas turbine (1.36 MWe) with intercooling, heat recuperation and low working temperature (860 ºC).

Waste heat (670 kWth) at 198 ºC for water heating and space cooling/heating.

Operation in a fuel-saver mode As in the case of dish system parks, the small tower

fields for distributed power should target maximum unattended operation, to minimize O&M costs.

MIUS solar tower technical specifications

Tower optical height (m)Number heliostatsHeliostat surface (m2)Receiver surface (m2)Receiver tilt angle (º)Land (m2)

26345

19.216.5

3038,000

Design point Power Efficiency

DNI (W/m2)Power onto mirrors area (MWt)Gross power onto receiver (MWt)Power to turbine (MWt)Gross electric power (MWe)Total efficiency

8755.84.33.41.4----

----100 %

74 %80 %39 %23 %

InvestmentHeliostatsLandTowerReceiverInst.&ControlPower blockFixed cost

995,765 $62,745 $

104,575 $484,750 $107,000 $

1,146,000 $65,350 $

Direct capital cost 2.97 M$Installed cost (including turbine set) 2,120 $/kW

Electrical power 1,407 kWeThermal power 1,200 kWthFuel consumption 3,280 kWHeat rate 8,392 kJ/kWhElectrical efficiency 42.9 %Thermal efficiency 36.6 %Total efficiency 79.5 %NOx emission <20 g/GJ

Heron H1 Technical Specifications

1.36 MWe

Recuperator

HPC LPC

C2 C3 PT

PR=3.0

PR=3.0 PR=2.7

8.9 bar151 ºC

Intercooler

3.0 bar25 ºC

3.0 bar137 ºC

1.0 bar15 ºC

Air filter

1.0 bar15 ºC Air inlet

m=5.15 kg/s

1.0 bar198 ºC

1.0 bar573 ºC

8.9 bar573 ºC

8.9 bar860 ºC

3.1 bar635 ºC

3.1 bar860 ºC

Heatflow SOLAR R1-R6 = 1.95 MWHeatflow SOLAR R7-R10 = 1.49 MW

Total = 3.44 MW

C1

R3R2R1

R6R5R4

R7 R8

R9 R10

661 ºC 757 ºC740 ºC

Theoretical solarization based on Turbine Heron H-1 and 10 pressurized volumetric receivers

MIUS Solar Tower: Application to a shopping center

Solar electricity production = 2,456 MWhFossil electricity production = 1,892 MWhSolar electricity excess = 428 MWh

MIUS Solar Tower: Application to a shopping center

56 % power demand supplied by solar (683 toe)

Few hours at loads of 20 % during start-ups

Typical solar working load 75 %

MIUS Solar Tower: Application to a shopping center

Solar is contributing to the waste heat produced with 4,374 GJ that represents 49.5% of the heat demand.

CONCLUSIONS

CSP is focusing its growth still on first generation large-fields

The solar field should be small and modular to account for the maximum flexibility in approaching real systems.

Up to 60% future cost reduction should come from R&D.

Solgemac project objectives are modularity, dispatchability and efficiency by high flux/high T.

A potential niche for the application of dish-engine systems and small solar towers to Modular Integrated Utility Systems has been identified.