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A Techno-Economic Analysis of Parabolic Trough CSP Plants for Profitability
Enhancement
Nogues OllierMEng candidate
Supervisor: Prof Thomas Harms
Solar Thermal Energy Research Group (STERG), University of Stellenbosch
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CSP: solution to renewable energy intermittency. Parabolic trough technology is the most mature. High
LCOE needs to be reduced.
Understand the cost drivers.
Literature review.
Evaluate available techno-economic
options.
Literature review.
Measure the profitability enhancement potential of
the most promising options.
Modelling:
System Advisor Model (SAM).
Reference plant.
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36%45% 44% 38% 37%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
6 hours TES(Hinkley, 2011)
6.3 hours TES(Turchi, 2010)
4.5 hours TES(Fichtner,
2010)
9 hours TES(Fichtner,
2010)
13.4 hoursTES (Fichtner,
2010)
Site improvement Solar field HTF system
Energy storage Power block and BOP Indirect costs
Source: IRENA (2016) in New Energy Update: CSP (2019)
Breakdown of the LCOE Breakdown of the initial investment for 100 MW
Capital cost (Initial investment)
37%
Capital cost (Interest payment)
47%
Operation and Maintenance
11%
Insurance5%
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Solar field HTF TES Scale-up Project Financing
ReduceCAPEX: largercollectors:Ultimate Trough
• Performance:selective coating; Mirror reflectivity
Molten salt• Direct steam
generation• Air
Direct 2-tank
• Thermo-cline
• Latent heat
• Thermo-chemical
• Economies of scale
Lower debt interest rate
Tax incentives
Public finance
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Site: (-28.537, 21.078), 2630 kWh/m^2/year
Input/Assumptions
• Solar field: EuroTrough collector (150 m
long, 5.75 m wide); Schott PTR70 2008
receiver.
• HTF: Therminol VP-1 (293-393 °C)
• Thermal Energy Storage: 5 hours; Hitec
XL molten salt; 2-tank indirect.
• Power block: 100 MW net; Dry cooling;
Cycle efficiency = 36.4 %.
• Capacity factor: 45 %.
• Financing: 25 years PPA; 10 % interest
rate; 16 % target IRR; DSCR = 1.35; 10 %
discount rate.Source of TMY weather data: European Commission (2019)
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Input/Assumptions: Adapted from
Ruegamer et al. (2013)
• Ultimate Trough: 247 m long;
7.5 m aperture.
• Schott PTR80 receiver: 80 mm OD.
• Solar field specific cost ($/m^2):
-13 % for 4 SCAs/loop; -6.5% for 2
SCAs/loop.
23.723.6
22.7
22.2
22.4
22.6
22.8
23.0
23.2
23.4
23.6
23.8
Reference plant Ultimate Trough(4 SCAs/loop)
Ultimate Trough(2 SCAs/loop)
Nom
inal LC
OE
[U
SD
c/k
Wh]
4 %
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Input/Assumptions: Adapted from
Ruegamer et al. (2013)
• Cycle efficiency: 41 % for Solar
Salt; 39 % for Hitec XL.
• Solar field cost ($/m^2): +6 %
• TES cost ($/kWhth): -50 % for Hitec
XL; -60 % for Solar Salt.
• Power block cost ($/kWe): -15 % for
Hitec XL; -17 % for Solar Salt.
23.7
22.0
20.3
18.0
19.0
20.0
21.0
22.0
23.0
24.0
Reference Plant Solar Salt HTF at 550 °C(Direct two-tank storage)
Hitec XL HTF at 490 °C(Direct two-tank storage)
Nom
inal LC
OE
[U
SD
c/k
Wh]
7 %14 %
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23.7 23.5 23.3 23.7
21.2
19.0
17.0
15.1
13.4
0.0
5.0
10.0
15.0
20.0
25.0
16% 14% 12% 10% 8% 6% 4% 2% 0%
Nom
inal LC
OE
[U
SD
c/k
Wh]
Equity rate. Debt interest rate = 10 %. Debt interest rate. Equity rate = 16 %
23.721.9
20.218.4
16.715.0
19.217.9
16.715.4
14.213.0
0.0
5.0
10.0
15.0
20.0
25.0
0% 10% 20% 30% 40% 50%
Nom
inal LC
OE
[U
SD
c/k
Wh] and
NP
V [
mill
ion U
SD
]
Investment tax credit
Nominal LCOE Net Present Value (NPV)
Effect of reducing equity rate and debt interest rate The effect of investment tax credits (ITC)
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23.7 22.7
19.4
15.714.6
0
5
10
15
20
25
Reference plantEuroTrough
VP-1 at 393 °C
UltimateTrough
Hitec XLat 490 °C
Reducedinterest rate: 6 %
Investment TaxCredit: 10 %
Nom
inal LC
OE
[U
SD
c/k
Wh]
4 %
14.5 %19 %
7 %
38 %
18 %
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19
19.5
20
20.5
21
21.5
25% 50% 75% 100% 125% 150% 175%
Nom
inal LC
OE
[U
SD
c/k
Wh]
Variation in assumptions
Solar field cost
Thermal energy storage cost
Power plant cost
Balance of plant cost
22.621.6
18.6
14.513.4
0.0
5.0
10.0
15.0
20.0
25.0
Reference plantEuroTrough
VP-1 at 393 °C
UltimateTrough
Hitec XLat 490 °C
Reducedinterest rate: 2 %
Investment TaxCredit: 10 %
Nom
inal LC
OE
[U
SD
c/k
Wh]
Location and Financial Parameters: Spain. DNI = 2120 kWh/m^2/year. Interest Rate = 6 %.
4.5 %
14 %
22 %
7.5 %
41 %
18 %
HTF and TES model
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23.0 22.7 22.7 23.0
20.5
18.3
16.3
14.512.9
0.0
5.0
10.0
15.0
20.0
25.0
16% 14% 12% 10% 8% 6% 4% 2% 0%
Nom
inal LC
OE
[U
SD
c/k
Wh]
Equity rate. Debt interest rate = 10 %. Debt interest rate. Equity rate = 16 %
Modified Parameter:
• Decrease DSCR from 1.35 to 1.2
• Results are not affected.
Effect of reducing equity rate and interest rate
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• Most important cost drivers: installed cost dominated by the solar field;
financing costs (interest payment).
• Most promising cost reduction paths:
1. Reduce capital cost: solar field offers more opportunity
2. Improve financing conditions to reduce interest payment. Public financing tools are
important to reduce the perceived financial risk.
3. Performance improvement: molten salt heat transfer fluid and direct two-tank storage.
• Cost reduction potential:
1. Ultimate Trough (also other large collectors) found to reduce nominal LCOE by 4 %.
Could be more.
2. Hitec XL is currently more appropriate as molten salt HTF: ~14 % reduction in LCOE.
3. Decreasing interest rate by 4 %: ~19-22 % reduction in LCOE.
4. Investment tax credit: LCOE reduction by 1.7 USD c/kWh for every 10 % credit.
5. Cumulative cost reduction potential: 38-41 %
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• CH4 Energy Group. 2019. Concentrated Solar Power (CSP) [Online]. Available:
http://www.ch4energygroup.com/csp/ [2019, July 15].
• European Commission. 2019. Photovoltaic geographical information systems [Online]. Available:
http://re.jrc.ec.europa.eu/pvg_tools/en/tools.html#TMY [2019, July 15].
• New Energy Update: CSP. 2019. World’s largest CSP project achieves financial closure [Online].
Available: http://newenergyupdate.com/csp-today/worlds-largest-csp-project-achieves-financial-closure-us-
announces-33mn-csp-funding [2019, July 15].
• Ruegamer, T., Kamp, H., Kuckelkorn, T., Schiel, W., Weinrebe, G., Nava, P., & Richert, T. 2013. Molten
salt for parabolic trough applications: system simulation and scale effects. Energy Procedia. 49:1523-1532.
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ACKNOWLEDGEMENTS:
CONTACT DETAILS:
visit us: concentrating.sun.ac.za
Solar Thermal Energy Research Group (STERG)Stellenbosch University South Africa
The Mandela Rhodes Foundation
Kathu Solar Park (RF) Pty Ltd
[email protected]+27 (0)21 808 4016