Advanced qualification methods for parabolic trough receivers SCHOTT Solar CSP Riyadh, November 20 th 2013
2 SCHOTT Solar CSP develops and supplies receivers for linear focusing CSP technologies
3 Since the market entry in 2005, SCHOTT Solar CSP has achieved a leading market position CSP capacity installed or under construction More than 3 Gigawatts capacity equipped with SCHOTT PTR 70 receivers ~ 3 GW 0,35 GW 2005 ~ 1 GW 2013 Supplied over 1.000.000 receivers to more than 50 CSP projects worldwide
4 All existing CSP plants in MENA are equipped with SCHOTT receivers Ain Beni Mathar 450 MW ISCCS plus 25 MW parabolic trough solar field Operating Hassi-R mel 130 MW ISCCS plus 25 MW parabolic trough solar field Operating Kuraymat 146 MW ISCCS with 30 MW parabolic trough solar field Operating Shams 100 MW stand-alone power plant at Shams Operating : end 2012
The key optical receiver parameters are aperture length, transmission of glass tube, absorptance of absorber tube and emittance of absorber tube 5 Solar 1 2 3 irradiation Shading losses Reflection losses glass Reflection losses absorber Stability of Glass-to-Metal Seal vacuum absorber 4m x 70mm absorber 4m x 70mm absorber Gas conduction heat losses Vacuum stability 4 Radiation heat losses Related receiver parameters 1 Aperture length in % 2 Transmission of glass tube (tau) in % 3 Absorptance of absorber tube (alpha) in % Emittance of absorber tube (epsilon) in % 4
6 The process technologies involved in SCHOTT s receiver production are leading edge Anti-reflective coating of the glass tube ensures high transmittance and high abrasion resistance Absorber coating achieves low emittance and high absorptance of the absorber tube SCHOTT PTR 3rd generation Vacuum insulation minimizes heat conduction losses Durable glass-to-metal seal material combination with matching coefficients of thermal expansion Optimized design of bellows achieves a maximum optical aperture length of the receivers
7 SCHOTT pursues a continuous improvement of its PTR receiver SCHOTT PTR 70 Receiver Development + 2.9% plant efficiency SCHOTT PTR 1 st Gen SCHOTT PTR 2 nd Gen + 1.0% plant efficiency SCHOTT PTR 3 rd Gen + noble gas capsule = life-time insurance SCHOTT PTR 3 rd Gen Premium high temperature (550 C) SCHOTT PTR 4 th Gen 2006 2008 2011 2012 2013
8 Based on a new receiver platform, SCHOTT issues three receiver products SCHOTT PTR 4 th generation receiver platform SCHOTT PTR 70 Advance New steel grade for 550 C + Novel absorber coating + Molten Salt SCHOTT PTR 70 Premium + Integrated Noble Gas Capsule as lifetime extender Oil SCHOTT PTR 70 New bellow design, suitable for high-temperature operation Glass-to-metal seal with matching coefficients of thermal expansions Protection cap for improved product robustness and easy handling Oil
9 The receiver component is the key lever between investment and return for any parabolic trough plant Less investment at same plant output 1% improved receiver efficiency significantly impacts investment required while maintaining equal plant output 0.8-1.2% less plant Capex $1.3-1.7m savings for a 50MW plant + 1% receiver efficiency Higher plant output at same investment 1% improved receiver efficiency significantly increases plant output while maintaining investment constant 0.9-1.4% improved efficiency, directly translating into plant output Effect of 1% improved receiver efficiency Investment standard receiver -$1.3-1.7m SCHOTT receiver +0.9-1.4% Plant output
At typical operation temperatures for oil-based HTF, a 1% points better absorptance or emittance translate to approximately 0.7 % lower LCOE 10 Sensitivity alpha/epsilon for operation temperatures 391 C and 550 C * Operation temperature 391 C: Similar impact of alpha and epsilon Operation temperature 550 C: Higher impact of epsilon * based on SAM simulation of 100 MW plant, storage 7,5h, location Almeria (Spain)
1.349.640 2.197.240 1.656.080 4.238.000 5.652.840 3.481.680 9.969.080 9.128.000 27.384.000 SCHOTT Solar CSP Using a receiver with 1% lower absorptance, 1% higher emittance and 0,3% lower active length leads to over 4 musd additional solar field cost for a large CSP plant in US 11 Additional solar field costs (US$) using competitor products vs. SCHOTT Gen 3 receiver 30.000.000 25.000.000 Optical parameter (%) SCHO TT Competitor product Gen 3 A B C 20.000.000 absorptance 95,5 94,5 94,5 94,5 emittance 9,5 10,5 11,5 15 15.000.000 10.000.000 transmittance glass tube active length @ > 300 C 96,5 96,5 96,5 96,5 96,7 96,4 96,1 95,4 5.000.000 * reference net electricity output 0 Daggett (USA) 250MW, no TES Almeria (Spain) 50MW, no TES Almeria (Spain) 50MW, 7.5 hours TES 519,5 GWh/a 84,3 GWh/a 137,0 GWh/a Plant assumptions Size of solar field is adapted to reach the net electricity output using SCHOTT Gen3 receivers * Specific solar field costs: 326 $/sqm competitor product A competitor product B competitor product C
-28,0-9,8-7,9-4,8-4,4-3,0-1,2-1,8-1,5 SCHOTT Solar CSP Using a receiver with 1% lower absorptance, 1% higher emittance and 0,3% lower active length results in 4,8 GWh less annual electricity output for a large CSP plant in US 12 Difference in net electricity output (GWh/a) using competitor products vs. SCHOTT Gen 3 receiver reference net electricity output 0,0 519,5 GWh/a 84,3 GWh/a 137,0 GWh/a Daggett (USA) 250MW, no TES Almeria (Spain) 50MW, no TES Almeria (Spain) 50MW, 7.5 hours TES Optical parameter (%) SCHO TT Competitor product Gen 3 A B C absorptance 95,5 94,5 94,5 94,5-5,0 emittance 9,5 10,5 11,5 15-10,0 transmittance glass tube active length @ > 300 C 96,5 96,5 96,5 96,5 96,7 96,4 96,1 95,4-15,0-20,0-25,0-30,0 competitor product A competitor product B competitor product C
Degradation of receiver performance over operation time affects the profitability of a CSP plant. Excellent optical and thermal properties must be validated for the full plant lifetime 13 a, e, t (initial) a, e, t (after x years of operation) GWh Net electricity output Efficiency gap time
14 DLR developed advanced validation methods for performance and aging of parabolic trough receivers DLR objective: Provide most advanced measurement and validation methods for performance of Parabolic trough receivers Approach: Development of measurement technology Publication Standardization Independent measurement services Results are relevant for: EPC companies Owners and plant operators Receiver manufacturers
15 The DLR approach covers tests for optical and thermal performance as well as aging and fatigue tests Performance Tests Accelerated ageing tests
16 Solar simulator receiver test bench approach Principle: calorimetric measurement of optical efficiency Conditions: solar simulator lamps elliptical mirror trough with flat end mirrors receiver at room temperature relative measurement (reference receiver)
17 The DLR optical performance testing method uses the most realistic approach
18 Test bench generations 1st generation (ElliRec) 2nd generation (OptiRec) also used at SCHOTT Solar CSP R&D
In addition to the laboratory test benches, receiver performance is validated in a real parabolic trough collector at the KONTAS test facility by DLR-CIEMAT 19
20 DLR measurements are the basis of thermal performance data provided in the receiver specifications Measurement results of specific heat loss of the 4 th generation SCHOTT PTR receiver (W/m) Example: 4 th generation of SCHOTT PTR Receiver Single sample measurement, no statistical data
The combination of accelerated aging tests and optical tests provide quantitative evaluation of receiver performance over lifetime 21 Changes of optical parameters during accelerated aging tests @ 650 C (absolute % points) Example: SCHOTT PTR Advance Receiver for usage with Molten Salts Single sample measurement, no statistical data
22 Test results are publically available and can be used as basis for supplier selection within EPC tenders Publication on DLR website Usage as basis for supplier selection within EPC tenders
23 Summary Based on unique technology innovations, SCHOTT Solar CSP achieved a leading market position for solar receivers For validation of new receiver products, DLR provides leading edge test methods and hardware to measure performance and lifetime The DLR methods represent a quasi-standard in the industry. They are used within SCHOTT s receiver product development and qualification The standardized test reports by DLR are publically available and can be used as basis for supplier selection within EPC tenders