Lahmeyer International 2013Lahmeyer International 2013

Lahmeyer International GmbHEngineering and Consulting Services Energy Division; Business Unit Renewables and Economics

Initial Performance History - O&M Lessons LearnedKuno SchallenbergKuno.Schallenberg@de.lahmeyer.com+49 6101 55 1886

26 August 2013

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Solar Tower Technology

Brief facts on the current status:

• 3 operational projects considered commercial:

– PS-10 (10 MW)

– PS-20 (20 MW), and

– Gemasolar (20 MW)

• Large commercial projects under construction (e.g. Ivanpah)

• Some pilot and demonstration experiences around the world (e.g. Solar One, Solar Two, Themis, etc.)

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Tower Project Focus: Gemasolar (Spain)

Source: Torresol

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Gemasolar: Key Data

Source: Torresol

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Gemasolar: Layout

Decoupled System

Source: Torresol

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Gemasolar: Plant behaviour (full summer week)Meinel DNI (W/m²)

Actual DNI (W/m²)

Heliostats focusing (u)

Receiver Power (MWt)

Storage Level (%)

Gas use (kg/s)

Net Output (MWe)

Source: Torresol

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Gemasolar: Operation - Preliminary Results

• Plant is still on ramp-up period (2nd operational year)

• Performance exceeds expectations on clear sky days but is lower than expected on cloudy days

• Plant can operate continuously 24 hours/day (mainly summer)

• Fine control of solar field and receiver temperature achieved

• Cleanness factor of the solar field exceeds 95%

• Storage tanks loose around 1°C/day in average

• Water consumption per year rounds 400,000 m³

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Gemasolar: Operation Event – Frozen Receiver

• Event: Frozen salts on receiver tubes

• Cause: operation exceeding boundary conditions (high winds)

• Solution: gradual heating of the tubes using the solar field

• Result: salts were melted and tubes freed

• Consecuences: no mechanical or structural damages to the receiver

Source: Torresol

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Gemasolar: Maintenance

Source: Torresol

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Gemasolar: Maintenance – Key Facts

• Typical maintenance activities: preventive, predictive and corrective

• Major emphasis on predictive maintenance, especially on non-conventional equipment (e.g. receiver, salt pumps, etc.)

• Annual plant inspection (scheduled corrective maintenance) with a duration of 3-4 weeks

• Turbine has shown no signs of degradation, performing substantially better than in other CSP plants

• No perceived degradation on Receiver

• No special maintenance activities on salt system (no corrosion noted)

• Exceptions: valves (salt system) and kettle

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Gemasolar: O&M Personnel

• Operation (on site):

– Around 20 employees which include supervisors, EHS, process engineers and operators, divided into 5 shifts

• Maintenance:

– Around 30 employees which include supervisors, electromechanical technicians, chemical engineer and cleaning crews

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Gemasolar: O&M Costs

46%

2%

29%

15% 8%Owner's Costs

EHS Costs

General Costs

Maintenance Costs

Operation Costs

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Trough Technology

Brief facts on the current status:

• Around 3 GW installed worldwide

• Large commercial projects still announced

• Almost 30 years of operational track record (SEGS I built on 1984)

• Relatively mature O&M experience

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Trough Project Focus: Typical 50 MW installation with TES (Spain)

Source: Torresol

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Trough Case Study: Key Data

Source: Torresol

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Trough Case Study: Typical Plant Layout

Source: Torresol

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Trough Case Study: Plant behaviour (clear and cloudy days)

Source: Torresol

Stored Energy Gas Heater Turbine Output

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Trough Case Study: O&M Results - Spain

• Performance results are not similar/homogeneous within the plants installed recently (last 5 years) in Spain

• Some plants register 15 to 20% higher annual performance compared to expected values

• Experience from SEGS plants allowed optimization of O&M e.g. high performance, effective maintenance (predictive) and cost reduction

• Major O&M incidents relate to HTF leakages (e.g. ball joints, flexible hoses), HTF pumps failure, HTF filtration into water/steam cycle, broken absorber tubes

• There are no major incidents with the operation of the TES reported

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Conclusions & Lessons learned

• Operation with molten salt systems as HTF is more delicate on changing weather conditions (e.g. cloud passages)

• Decoupled systems with TES allow reduction and/or elimination of weather disturbances on the solar field (e.g. cloud passages), allowing a better operation of the turbine

• No special events detected on the operation of molten salt storage systems

• O&M cost reductions on existing plants are very unlikely without losing plant performance

• Increasing project size or multiproject development might be the only way to reduce O&M costs

• CSP integration to existing thermal power plants represent a significant reduction on O&M costs for the solar part (e.g. almost no additional labor)

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Thank you for your Attention

Questions?