Overview of thermal energy storage technologies and applications by - - PowerPoint PPT Presentation

Overview of thermal energy storage technologies and applications

by Dr Peter Klein CSIR

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Agenda

• 1. Why thermal energy storage
• 2. Description of thermal energy storage technologies
• 3. Identification of applications
• 4. Thermal storage testing laboratory
• 5. Conclusions

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Importance of energy storage

Increasing penetration of variable renewable energy generators requires flexibility

1Based on draft Integrated Resource Plan 2018

20 40 60 80 100 32% 16% 17% 19% [GW] 13% 23% 2020 2030 IRP1 2030 IRP3 12% 18% 2040 IRP1 2050 IRP3 29% 2040 IRP3 21% 34% 2050 IRP1 29% 4% 3%

Installed capacity Energy mix

Solar PV Wind 50 100 150 200 250 [TWh] 2040 IRP1 36% 8% 7% 1% 28% 3% 2020 13% 2030 IRP1 14% 2030 IRP3 15% 13% 25% 2040 IRP3 20% 42% 2050 IRP1 16% 2050 IRP3 Solar PV Wind

Percentages indicate fraction of total generation installed capacity and energy mix

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5 10 15 20 25 30 35 40 45 50 55 60 65 70

Thursday Day of the week GW Wednesday Sunday Monday Tuesday Friday Saturday

Future energy system will be built around variability of solar PV & wind

Actual scaled RSA demand & simulated 15-minute solar PV/wind power supply for week from 15-21 Aug ‘11

Excess Solar PV/Wind Residual Load (flexible power) Useful Solar PV Useful Wind

Sources: CSIR analysis

Electricity Demand

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Value of a Flexible Energy System

0% load flexible Excess Deficit

• 30
• 25
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• 5

5 10 15 20 25 30

Flexible Gas (CCGT) Peaking Gas (OCGT) Energy curtailed

In order of 15% of generated energy curtailed in models

Friday Day of the week GW Monday Tuesday Wednesday Sunday Saturday Thursday

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Excess Deficit

• 30
• 25
• 20
• 15
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• 5

5 10 15 20 25 30 GW Sunday Saturday Friday Thursday Wednesday Tuesday Monday Day of the week

• 30
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5 10 15 20 25 30 No Flexible Load

Value of a Flexible Energy System

25% load flexible – energy balanced intraday

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Value of an Integrated Energy System

25% load flexible – energy balanced intraweek

No Flexible Load

Excess Deficit

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• 25
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5 10 15 20 25 30 GW Sunday Saturday Friday Thursday Wednesday Tuesday Monday Day of the week

• 30
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5 10 15 20 25 30

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So why use thermal energy storage for flexibility?

Thermal energy is the dominant energy end-use

Power-to-Heat/Cold

• Solar Thermal (CSP)
• Waste Heat Recovery
• Biomass
• Heat/Cold from Ambient
• Absorption Chillers

Thermal Battery (TES) Energy End-Use

Advantages of TES

• Low cost
• Low tech
• Potential for seasonal storage and high energy storage densities (thermochemical)
• High storage efficiencies
• Scalable and modular
• Wide operating conditions
• Deployed at GWh scale or residential
• Can size power and energy independently

Concept preferably requires thermal energy for end-use

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So why use thermal energy storage for flexibility?

Thermal energy is the dominant energy end-use =92% =77% =71% 37% Final Energy Consumption2 6% Final Energy Consumption2 22% Final Energy Consumption2

1Based on DoE calculations in draft Integrated Energy Plan 2016 2Based on IEA Energy Balances for 2015

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Chemicals Iron and Steel

13% 87% Thermal Non-Thermal 65% 35%

Non-ferrous metals Other manufacturing

33% 67% 46% 54%

Gold mining Platinum mining

21% 79% 21% 79%

Based on DoE calculations in draft Integrated Energy Plan 2012

End-use of electricity in industry in South Africa

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Integrating thermal storage into industry

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Thermal Energy Storage Thermal Sensible Heat Liquids Solids Latent Heat Solid-Liquid Liquid-Gas Solid-Solid Chemical Solid-Gas Reactions Liquid-Gas Reactions Gas-Gas Reactions

Overview of Thermal Energy Storage Technologies

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Energy stored if no phase change Charging Discharging Sensible heat TES Latent heat TES PCM

Comparison of sensible and latent heat storage technologies

Energy Stored Discharge Temperature

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Sensible heat storage overview

• L. Heller, Literature Review on Heat Transfer Fluids, STERG Report, 2013.
• W. B. Stine and M. Geyer, “Power from the sun. Retrieved April 15, 2011, from http://www.powerfromthesun.net/book.html,” 2001.

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Latent heat storage overview

Hoshi, Akira, et al. "Screening of high melting point phase change materials (PCM) in solar thermal concentrating technology based on CLFR." Solar Energy 79.3 (2005): 332-339.

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Latent heat storage: Ice storage for HVAC

https://www.energy-storage.news

Southern California Edison – 25.6MW of peak ice storage capacity 1800 behind the meter ice batteries, as part of 250 MW energy storage requirement

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1 000 2 000 3 000 4 000 5 000 6 000 2 4 6 8 10 12 14 16 18 20 22 24 Load [kW] 200 400 600 800 1 000 1 200 GHI [W/m2] 5 10 15 20 25 30 35 40 2 4 6 8 10 12 14 16 18 20 22 24

• Temp. [C]

5 10 15 20 25 30 35 40 2 4 6 8 10 12 14 16 18 20 22 24

• Temp. [C]

GHI and Temperature Load and Temperature

Alignment between Solar supply, load and temperature as measured in summer at CSIR campus

18 Charging (endothermic) Discharging (exothermic)

Thermochemical heat storage overview

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Example of adsorption storage system

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Comparison of Thermal Energy Storage Energy Densities

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Power-to-Heat Waste Heat Recovery Passive Applications

CSIR Energy Centre Thermal Storage Research

Key roles identified for Thermal Storage

Concentrating Solar Power

Utilise low cost thermal storage to shift thermal loads in time

Based on US DOE, Energy Storage Database (2017)

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Power-to-Heat Waste Heat Recovery

Key roles identified for Thermal Storage Waste heat recovery

• Smooth loads
• Batch-wise processes
• Increase efficiency
• Increase capacity factor
• Supply for peak loads
• Improve industrial efficiency

Electricity E

Thermal Storage

Heat H

• Couple electricity and heat

sectors

• Primarily from PV and wind
• Utilise low cost TES to add

flexibility

• Many existing loads can be

made flexible at low cost

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Waste Heat Recovery Pilot Project (WHR) under YREF grant

How can thermal storage be integrated into WHR systems + SMME development Waste heat from high temperature kilns >1000 oC Drying moulds at 60 oC Partnership with NCPC combining energy audit with research and development for non standard WHR solutions

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Waste Heat Recovery Boosted by TES

Addition of TES adds 33% to average power Slide from Romagnoli, A. “Waste heat recovery in industrial processes via thermal energy storage” National Energy Efficiency Conference 2015

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Passive Applications Concentrating Solar Power

Key roles identified for Thermal Storage

• Typically 2 tank molten salt
• Generate electricity
• Commercially mature (1.1GWh)
• Opportunities for cost reductions

with low cost materials (e.g. rocks)

• Cost competitive issue with

PV+battery

• Provide passive cooling in buildings HVAC
• Integrate thermal storage into building envelope
• Eliminate need for active cooling

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Thermal Storage Laboratory:

Excellent integration opportunity between Energy Materials and Energy Storage Low technology solutions Short time to market

• B. Zalba, J. M. Marin, L. F. Cabeza and H. Mehling, “Review on thermal energy storage with change: materials, heat

transfer analysis and applications,” Applied Thermal Engineering, vol. 23, pp. 251-283, 2003

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Conclusions

• 1. Thermal energy is the largest end-use of energy in South Africa
• 2. A range of TES technologies exist which can be incorporated to

add grid flexibility at low cost

• 3. In the near term TES for waste heat recovery presents an

interesting opportunity

• 4. CSIR Energy Centre is looking to develop new materials and

heat exchange designs for TES

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Thank you