csp parabolic trough technology for braziledge.rit.edu/edge/p15484/public/detailed design...

• CSP Parabolic Trough Technology for Brazil

• A comprehensive documentation on the current state of the art of parabolic trough collector technology

1. Introduction 1.1. History

1.2. Aspects for Parabolic Trough Design

2. Overview on Parabolic Trough Collectors 2.1. First Commercial Collector Generation

2.2. Currently Available Parabolic Trough Collectors

2.3. Recent Collector Developments

3. Financial Parameters 3.1. Levelized Cost of Electricity

3.2. Comparison of Parabolic Trough Power Plants

4. Technological Developments 4.1. General Trends

4.2. Further Cost Reduction Potential

19/03/2014 Content

In 45 minutes, the sun sends more energy to the earth than humans consume in an entire year. With solar power plants more power can be generated on only 1% of the earth’s deserts than fossil fuels produce globally today. The future belongs to whoever succeeds in using these reserves effectively and profitably. Investing here is investing in the market of the future. Our future energy supply must be based on the use of renewable energies. Solar power plants make a valuable contribution to a sustainable and climate-friendly generation of energy.

Concentrating Solar Power (CSP) allows to convert the existing Solar energy into dispatchable electricity.

19/03/2014 Introduction

Technology split of global CSP projects under construction, commissioning or already operational

as of Dec. 2013.

4

3424,245

707

Projects under construction, commissioning or operational

Dish

Fresnel

Parabolic Trough

Power Tower

Source: CSP Today Global Tracker, December 2013Source: CSP Today Global Tracker, December 2013

Parabolic Troughs are the single most important technology used.

19/03/2014 Introduction

An

da

so

l /S

pa

in

Sa

ud

i Ara

bia

Stu

ttg

art

500 m from tower

towards pole

500 m from tower

towards equator

500m East/West

Tower Height 180 m

Dish Stirling

Parabolic Trough

Tower

Fresnel

Bra

zil

Ca

lifo

rnia

19/03/2014 Comparison of CSP Technologies

Brazil:

Direct Normal Irradiation (DNI) at

a high level.

Higher DNI leads to lower

levelized cost of electricity

(LCoE).

0,00 €

0,05 €

0,10 €

0,15 €

0,20 €

0,25 €

0,30 €

0,35 €

1500 1750 2000 2250 2500 2750 3000 3250

LCO

E [€

/kW

h]

DNI [W/(m^2 * a)]

LCOE and direct normal iradiance (DNI)

design output: 50 MWstorage: 6 hO&M and insurance: 3 % of total investmentOperation time: 25 yearsInterest Rate : 8 %

19/03/2014 Solar Irradiance and LCOE










19/03/2014 Content

early 20th century

• First 45 kW parabolic trough collector plant by Shuman and Boys

80ies

• First commercial parabolic trough power plants in the Mojave Dessert in California (SEGS)

2004

• Introduction of feed in tarif (FIT) by the Spanish government

2008

• Andasol: first commercial parabolic trough power plant in Europe

19/03/2014 History

Andasol Plants (2009) 19/03/2014










19/03/2014 Content

Glass tube

Absorber tube with selective coating

Tracking system

Parabolic concentrator with reflecting surface

Direct radiation The trough is tracking the sun on a

single axis (elevation axis)

Direct radiation is focused on an

absorber tube

A heat transfer fluid pumped

through the absorber tube and is

heated up

Steam is produced and runs a

turbine

Heat is stored in storage tanks to

produce electricity on demand

Principle of a Solar Parabolic Trough Power Plant

19/03/2014

Parabolic Trough power plant functional principle

19/03/2014

Pros and Cons of Parabolic Troughs

19/03/2014

Pros

short distance between reflector and

absorber tube

low energy losses

delivers dispatchable energy

proven technology

bankable

lower part costs

lower LCoE

Proven technology

low area demand

low energy losses

Easy to scale

10 MW to 250 MW

Cons

limited operation temperature

(by heat transfer fluid)

higher cosine losses than dish

Even terrain required

Supporting Structure

19/03/2014

Torque Tube Torque Box Space Frame

Steel

Aluminum

+ high stiffness and strengths + low thermal expansion -- high mass

+ low mass -- low stiffness -- high thermal expansion

Genealogy of Parabolic Trough Collectors

19/03/2014

Content 19/03/2014










Collector Development

19/03/2014

LS-2:

- Torque tube design

- able to achieve good optical

accuracy

- easy to assemble

- good optical performance

- high costs

- aperture width: 5m

- SCE: 7.8 m

- SCE per SCA: 6

- SCA length: 47 m

LS-3:

- Space frame truss design

- 2x as long and larger aperture

- inadequate torsion stiffness

- cost savings not demonstrated

- lower optical performance

- aperture width: 5.76 m

- SCE: 12 m

- SCE per SCA: 8

- SCA length: 96 m

Content 19/03/2014










Euro Trough– Key figures

19/03/2014

Solar Collector Assembly SCA

SCA: 12 SCE per SCA

Length: 150 m

Aperture area: 816 m²

Drive: Hydraulic drive system

Solar Collector Element (SCE)

Structure: Torque boxes

Length: 12 m

Aperture width (gross): 5.76 m

Aperture area (net): 68 m²

HCE Diameter: 70 mm


19/03/2014

Solargenix (SGX) 2:

- used in 1 MW Saguaro Plant in

Arizona

- extruded aluminum space frame

- easy to assemble

- developed by Solargenix Energy and NREL

- SCA length: 96 m

- SCE: 8 m

- SCE per SCA: 12

- Aperture width: 5 m

EuroTrough:

- torque box of about 1.5 x 1.4 m to

increase stiffness

- 150 m long collectors

- high optical quality of the prototype

- used for 50 MW plants in Spain, Egypt, India and

the US

- developed by European companies

- SCE length: 12 m

- Aperture width: 5.76 m

- SCE per SCA: 12, SCA length: 150 m


19/03/2014

SENERtrough

- Torque tube supported on

sleeve bearings

- stamped arms to support the

reflector panels

- most common collector today

- Aperture width: 5.76

- SCE length: 12 m

- SCA length: 150 m

ENEA collector

- Torque tube as main structure element

- Molten salt as heat transfer fluid

- reflector panels: special

aluminum honeycomb facet with

thin glass mirrors

- Developed by: ENEA (Italian National

Agency for New Technologies, Energy and

Sustainable Economic Development)


- SCA length: 100 m

Content 19/03/2014










New collector developments

19/03/2014

HelioTrough

- torque tube with constant stiffness

along the whole collector

- reduced number of parts (mirrors,

HCE etc.)

- Increased lifetime

- cost reduction of maintenance and assembly

- Improved optical efficiency

- Aperture width: 6.78 m, Aperture area; 1263 m²

- SCE: 19 m / SCA: 191 m

- Developed by: sbp and Flagsol

Ultimate Trough

- world largest collector

- peak optical efficiency of 82.7%

- truss torque box desgin

- continuous mirror surface

- economic use of material

- high stiffness allows increased span of 24.5 meter

- Aperture: 7.51 m, Aperture area: 1716 m²

- SCE: 24.6 m, SCA length: 240 m

- total solar field cost savings up to 20 %

- Prototype in California

- Developed by: sbp, Flabeg (German Consortium)

New collector developments 19/03/2014

SENERtrough

- torque tube

- increased aperture width, collector element length

and focal length

- drive pylon structure: vertical pipe

- Developed by SENER

- Aperture width: 6.87

- SCE length: 13.2 m

- SCE per SCA: 12

- aperture area / SCA: 1048 m²

SkyTrough

- aluminum space frame

- reflective polymer mirror film attached on an

aluminum sheed instead of reflector panels

- aperture width: 6 m

- SCE length: 14 m

- SCA: 115 m

- aperture area / SCA: 656 m²

- Developed by: Skyfuel

New collector developments

19/03/2014

Large Aperture Trough (LAT) 73

- aluminum space frame

- reflective polymer film


- SCE length: 12 m

- SCA: 192 m

- Aperture area / SCA: 1392

- developed by Gossamer Space Frames and 3M

Abengoa E2

- steel space frame collector

- Aperture width: 5.76 m(LS-3)

- SCA length: 125 m

- monolithic glass reflector panels

- developed by Abengoa

Content 19/03/2014










Levelized Cost of Electricity LCoE

19/03/2014

• Overall performance value

• Usually used to compare different options for power generation

• Calculation:

Total investment costs incl. all expenses (e.g. O&M, taxes, insurance) divided by cumulated

electric energy produced during the complete operational time

• Unit: € / kWh

• Parametric calculation to show the impact of the DNI

on the LCOE (50 MW with 6 h storage)

0,00 €

0,05 €

0,10 €

0,15 €

0,20 €

0,25 €

0,30 €

0,35 €

1500 1750 2000 2250 2500 2750 3000 3250

LCO

E [€

/kW

h]

DNI [W/(m^2 * a)]

LCOE and direct normal iradiance (DNI)

design output: 50 MWstorage: 6 hO&M and insurance: 3 % of total investmentOperation time: 25 yearsInterest Rate : 8 %

Content 19/03/2014










Electric Output and Thermal Storage

19/03/2014

50 MW 50 MW 100 MW 100 MW 200 MW 200 MW

6 h Storage w/o Storage 6 h Storage w/o Storage 6 h Storage w/o Storage

M€ 213 125 392 232 726 420

M€ 7 4 14 9 28 16

M€ 58 35 111 67 215 120

M€ 14 7 26 14 50 27

M€ 5 3 8 5 15 9

M€ 60 57 110 105 200 190

M€ 40 0 69 0 120 0

M€ 22 13 41 25 75 44

M€ 7 4 12 8 22 13

M€/MW 4 3 4 2 4 2

M€ 14 8 25 15 47 27

M€ 6 4 12 7 22 13

k€/MW/a 128 75 118 70 109 63

M€/a 20 12 37 22 68 40

€/kWh 0,108 € 0,111 € 0,098 € 0,102 € 0,094 € 0,095 €

Total annual costs

LCOE

Owner costs

spec. Investments

annuity of investment costs

O&M costs and insurance

spec. O&M costs

HTF system (with HTF)

other solar field costs

power block

storage

EPC costs

Investment costs

Earth works & Foundations

Parabolic trough costs

Comparison of Parabolic Troughs Power Plants • EuroTrough collector (established, reliable performance data)

• Solar irradiance (DNI): 2500 W/m^2

• Operational period: 25 years

Electric Output and Thermal Storage

19/03/2014

Comparison of Parabolic Troughs Power Plants

50

60

70

80

90

100

50 100 200

LCO

E, n

orm

ali

zed

[%]

design output [MW]

LCOE (normalized ): impact of TES and up-scaling

without TES

with TES

(LCOE normalized to 50MW design output and without TES)

LCOE can be reduced by

• Power plant scale-up (parabolic trough collector scale-up not considered here)

• Integration of thermal storage (increased controllability, utilization of the turbine)

Content 19/03/2014










Improvements of current generation collectors 19/03/2014

EuroTrough, 510‘120 m² UltimateTrough®, 466‘731 m² 1‘500 m 1‘750 m

1‘0

50 m

1‘3

00 m

The Ultimate Trough® shows a cost reduction of about 20 to 25% compared to the

EuroTrough by:

decreasing specific solar field cost [€/m²] by “going large”

increased of optical performance (8%) by stress free mirror attachment

Due to increased collector dimensions & optical performance one UT loop will have more

than twice the thermal power compared with ET Loop

Header piping ET UT Ratio

north-south [m] 1'678 n/a

east-west [m] 6'840 3'757 55%

total [m] 8'518 3'757 44%

HFT volume [m³] 1'813 1'353 75%

Comparison EuroTrough – Ultimate Trough

19/03/2014

Significant cost reduction due to

Number of “loop specific

parts” (Drives, Sensors, Local

Control Board, Cabling,

Swivel joints, Control &

Separation valves, loop

interconnection piping)

significantly reduced by 50 to

60%

Less piping (material,

installation, insulation)

Less heat transfer fluid

Lower installation,

commissioning and operation

cost

Collector Type EuroTrough UltimateTrough® Ratio UT/ET

Aperture Width m 5.77 7.51 130%

SCE length m 12.0 24.5 204%

SCA per SCA # 12 10 83%

SCA length m 147.8 246.7 167%

Aperture Area / SCA m² 817.5 1,716.0 210%

Solar field m² 510,120 466,731 91,5%

Capacity (gross) 8 h storage

MW 50 50 100%

Loops # 156 68 44%

SCE # 7,296 2,720 37%

Drives/ Sensors/ Controls # 608 272 45%

Pylon foundations # 7,800 2,992 38%

Swivel joint assemblies # 1,248 544 44%

Cross over pipes # 156 68 44%

Cost reduction by scale up 19/03/2014

Cost Reduction

by

20 - 25% (Compared to the currently available

EuroTrough collector)

Large scale

Low specific cost [€/m²] for structure, civil works and assembly by “going large” - 7.5 m Aperture

Largest Parabolic Trough Collector

significant reduction of parts with related cost savings

the amount of heat transfer fluid (HTF) is reduced by 25 %

overall solar field costs about 23 % less compared to EuroTrough

LCOE is decreased by about 11% compared to EuroTrough

Steel structure with low accuracy allows effective sourcing

Simplicity in assembly allows low skilled labor requirements

and time efficiency

Close to perfect - Intercept factor

• 99.2% @ 94 mm HCE

• 97.5% @ 70 mm HCE

Optimized for molten salt systems for higher energy efficiency

High optical accuracy

Innovative design

Source: Riffelmann et al.,

„Performance of the Ultimate Trough

Collector with Molten Salts as Heat

Transfer Fluid”, SolarPACES 2012,

Marrakesh, September 2012

Molten salt operation 19/03/2014

The Ultimate Trough® collector is ready for molten salt operation:

The higher concentration factor using a 70 mm receiver tube compensates the higher thermal losses at elevated temperatures while the intercept remains high at 97.5%.This leads to a significantly higher thermal efficiency compared to troughs with a lower concentration ratio.

Electrical isolation of HCE for impedance heating is available

HCE supports suitable for higher expansion length due to elevated temperatures are available

The commonly available receiver diameter of

70mm is the optimum diameter for the

Ultimate Trough high-aperture collector for

use with molten salt. The graph shows that

the maximum annual yield of a given power

plant (120MW gross output and 14h of

thermal storage, located in Daggett, U.S.) is

highest for a receiver diameter of 70mm.

Source: Riffelmann et al., „Performance of the

Ultimate Trough Collector with Molten Salts as

Heat Transfer Fluid”, SolarPACES 2012,

Marrakesh, September 2012

Higher operating

temperature

Requires higher concentration

ratio

Requires higher optical performance

550

560

570

580

590

600

610

620

60 70 80 90 100

Net

an

nu

al e

ne

rgy

[GW

h]

HCE diameter [mm]

LCoE Daggett [€-Cent/kWh]

19/03/2014

16,9

15,4

13,9

11,2 10,2

0

2

4

6

8

10

12

14

16

18

-9 % -10 %

-20 %

-10 % - 40 %

Content 19/03/2014










Further Cost Reduction Potential 19/03/2014

Reflectors:

Significant cost reductions in glass mirror manufacturing

Manufacturers increase accuracy and reflectivity

Anti-soiling coating reduce O&M costs

New reflector concepts: reflecting film / composite facets

Larger structures allows for smaller solar fields

this significantly reduces number of parts

cost savings (e.g. drives, pylons, sensors, controls)

Various drive concepts have been conceived and tested

Hydraulic drives are the most cost efficient solution

Manufacturers increase production procedures due to competition

Drives and control:

Metal support structure:

Absorber tubes (HCEs):

Manufacturers increase production procedures due to competition

Reduction of thermal losses by using new procedures

Development targets higher temperatures (> 500°C) for molten salt application

As a federal enterprise, GIZ supports the German Government in achieving its objectives in the field of international cooperation for sustainable development.

Published by Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH

Registered offices, Bonn and Eschborn, Germany

“CSP Parabolic Trough Technology for Brazil”

“Address of Programme here” T +55 61 2010-2070

E [email protected] I www.giz.de/brazil

Responsible

schlaich bergermann und partner, sbp sonne

gmbh

Author(s)

Finn von Reeken, Sarah Arbes, Dr. Gerhard

Weinrebe, Markus Wöhrbach, Jonathan

Finkbeiner

Photo credits

© GIZ/schlaich bergermann und partner

In cooperation with

mailto:[email protected]



http://www.giz.de/brazil

19/03/2014

csp parabolic trough technology for braziledge.rit.edu/edge/p15484/public/detailed design...

Documents