2012 IEEE EPECElectrical Power and Energy ConferenceResilient Green Energy Systems for a Sustainable Society

October 10-12, 2012London, Ontario, Canada

Technical and Financial Benefits of Electrical Energy Storage Hussein Ibrahim, Rachid Beguenane, Adel Merabet

Technical and Financial Benefits of Electrical Energy Storage Hussein Ibrahim, Rachid Beguenane, Adel Merabet

RMC Canada

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OUTLINEOUTLINE

� ELECTRICAL ENERGY STORAGE DEFINITION

� ENERGY STORAGE VALUE

� ENERGY STORAGE TECHNOLOGIES

� TECHNICAL BENEFITS OF ENERGY STORAGE

� SYSTEMS

� FINANCIAL BENEFITS OF ENERGY STORAGE SYSTEMS

� CONCLUSION

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ELECTRICAL ENERGY STORAGE DEFINITIONELECTRICAL ENERGY STORAGE DEFINITION

• Electrical Energy Storage (EES) refers to a process of converting electrical

energy from a power network into a form that can be stored for converting

back to electrical energy when needed [Source: Baker J.N., 1999 ]

[Source : www.Electricitystorage.org]

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ENERGY STORAGE VALUE ENERGY STORAGE VALUE

• Energy storage:

� Optimises the match between demand and generation

� reduction of greenhouse gases emissions;

� Improves the grid utilisation by storing and moving low-cost power into higherprice markets ���� reducing peak power prices.

� Complements the primary generation by reducing the cycling and dispatch oflarge fossil units meant for baseload.

� Increases the value and the amount of renewable energy in the grid ����transforming “take it when you can get it” into scheduled power.

� Improves the security and assurance of the grid ���� participation to voltageregulation, black start, frequency control, emergency power.

� Postpones the need for new transmission assets depending on where storageassets are placed.

� Support the distributed generation (DG) : Storage assets placed atdistribution-voltage substations and integrated into advanced DG devices anduninterruptible power systems.

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ENERGY STORAGE TECHNOLOGIESENERGY STORAGE TECHNOLOGIES

� Storage devices can be classified by :

1. Technology type :Mechanical, Electrical, Electrochemical

2. Power and energy rating :

Large scale, small scale

3. Application :

Power quality and reliability, Power network applications

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ENERGY STORAGE TECHNOLOGIESENERGY STORAGE TECHNOLOGIES

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ENERGY STORAGE TECHNOLOGIESENERGY STORAGE TECHNOLOGIES

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ENERGY STORAGE TECHNOLOGIESENERGY STORAGE TECHNOLOGIES

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TECHNICAL BENEFITS OF ENERGY STORAGE SYSTEMS TECHNICAL BENEFITS OF ENERGY STORAGE SYSTEMS

A. Generation

� Commodity Storage: Storing bulk energy generated at night for use during

peak demand periods during the day.

� Contingency Service: Contingency reserve is power capacity capable of

providing power to serve customer demand should a power facility fall

off-line.

� Area Control: Prevent unplanned transfer of power between one utility

and another.

� Grid Frequency Support: means real power provided to the electrical

distribution grid to reduce any sudden large load/generation imbalance

and maintain a state of frequency equilibrium for the system’s 60Hz.

� Black-Start: This refers to units with the capability to start-up on their

own in order to energize the transmission system and assist other

facilities to start-up and synchronize to the grid.

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B. Transmission and Distribution

� System Stability: The ability to maintain all system components on a

transmission line in synchronous operation with each other to prevent a

system collapse.

� Grid Angular Stability: means reducing power oscillations by injection and

absorption of real power.

� Grid Voltage Support: means power provided to the electrical distribution

grid to maintain voltages within the acceptable range between each end

of all power lines.

� Asset Deferral: Defer the need for additional transmission facilities by

supplementing and existing transmission facilities.

TECHNICAL BENEFITS OF ENERGY STORAGE SYSTEMS TECHNICAL BENEFITS OF ENERGY STORAGE SYSTEMS

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C. Energy Service

� Energy Management (Load Levelling / Peak Shaving): Load Levelling isrescheduling certain loads to cut electrical power demand, or the productionof energy during off-peak periods for storage and use during peak demandperiods. Whilst Peak Shaving is reducing electric usage during peak periodsor moving usage from the time of peak demand to off-peak periods.

� Unbalanced Load Compensation: This can be done in combination with four-wire inverters and also by injecting and absorbing power individually at eachphase to supply unbalanced loads.

� Power Quality improvement: This result in different issues including:Harmonics, Power Factor, Transients, Flicker, Sag and Swell, Spikes, etc.Energy storage systems (ESS) can mitigate these problems and provideelectrical service to the customer without any secondary oscillations ordisruptions to the electricity "waveform".

� Power Reliability: Can be presented as the percentage/ratio of interruptionin delivery of electric power versus total uptime. ESS can help providereliable electric service to consumers (UPS) to ‘ride-through’ a powerdisruption.

TECHNICAL BENEFITS OF ENERGY STORAGE SYSTEMS TECHNICAL BENEFITS OF ENERGY STORAGE SYSTEMS

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D. Supporting the Integration of Intermittent Renewable Energy Sources

� Frequency and synchronous spinning reserve support: Energy storage can provideprompt response to imbalances between generation and load without theemissions related to most conventional solutions.

� Transmission Curtailment Reduction: An EES unit located close to the windgeneration can allow the excess energy to be stored and then delivered at timeswhen the transmission system is not congested.

� Time Shifting: Wind turbines are considered as non-dispatchable resources. EEScan be used to store energy generated during periods of low demand and deliverit during periods of high demand.

� Forecast Hedge: Mitigation of errors (shortfalls) in wind energy bids into themarket prior to required delivery, thus reducing volatility of spot prices andmitigating risk exposure of consumers to this volatility.

� Fluctuation suppression: Wind farm generation frequency can be stabilized bysuppressing fluctuations (absorbing and discharging energy during short durationvariations in output).

TECHNICAL BENEFITS OF ENERGY STORAGE SYSTEMS TECHNICAL BENEFITS OF ENERGY STORAGE SYSTEMS

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FINANCIAL BENEFITS OF ENERGY STORAGE SYSTEMSFINANCIAL BENEFITS OF ENERGY STORAGE SYSTEMS

� Cost Reduction or Revenue Increase of Bulk Energy Arbitrage: Arbitrageinvolves purchase of inexpensive electricity available during low demandperiods to charge the storage plant, so that the low priced energy can beused or sold at a later time when the price for electricity is high.

� Cost Avoid or Revenue Increase of Central Generation Capacity: For areaswhere the supply of electric generation capacity is tight, energy storagecould be used to offset the need to: a) purchase and install new generationand/or b) “rent” generation capacity in the wholesale electricitymarketplace.

� Cost Avoid or Revenue Increase of Ancillary Services: These are what mightbe called support services used to keep the regional grid operating. Twomore familiar ones are spinning reserve and load following .

� Cost Avoid or Revenue Increase for Transmission Access/Congestion:

Transmission access/congestion charges can be avoided because theenergy storage is used.

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FINANCIAL BENEFITS OF ENERGY STORAGE SYSTEMSFINANCIAL BENEFITS OF ENERGY STORAGE SYSTEMS

� Reduced Demand Charges: Reduced demand charges are possible whenenergy storage is used to reduce an electricity end-user’s use of the electricgrid during times grid is high (peak electric demand periods).

� Reduced Reliability-related Financial Losses: This benefit is very end-user-specific and applies to commercial and industrial customers, primarilythose for which power outages cause moderate to significant losses.

� Reduced Power Quality-related Financial Losses: Power quality anomaliesof interest are those that cause loads to go off-line and/or that damageelectricity-using equipment and whose negative effects can be avoided ifstorage is used.

�

� Increased Revenue from Renewable Energy Sources: Storage could be usedto time-shift electricity generated by renewables. Energy is stored whendemand and price for power are low, so the energy can be used when (a)demand and price for power is high and (b) output from the intermittentrenewable generation is low.

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CONCLUSIONCONCLUSION

Energy Storage has the potential to become the sixth dimension of the electricity value chain with special near-term benefits for renewables and grid management.

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THANKS FOR YOUR ATTENTION

Questions?

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ANNEXANNEX

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ANNEXANNEX