Topic Contribution of hybrid energy and energy storage ... · (CSIC, UPM, UAM, CNH2, IMDEA) - Use of the unique experimental laboratories of CIEMAT to provide 25% of the time in experimental

Topic Contribution of hybrid energy and energy storage systems to the

integration of variable renewable energy in the power system

Marcos Lafoz Pastor

Hybridisation with fast energy storage technologies

Contribution of hybrid energy and energy storage systems to the integration of variable renewable energy in the power system

27 % of the final energy consumption will be covered by renewable energy in 2030.

46 % of electricity supplied will come from renewable energies.

Renewable energy penetration and the Grid Codes

This type of power generation is basically unpredictable and variable along the time, affecting to the Grid Codes.

1. Voltage regulation 2. Reactive power supply 3. Response to system fault 4. Response to frequency

changes 5. «ride through» short

interruptions

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Contribution of hybrid energy and energy storage systems to the integration of variable renewable energy in the power system

• Example: The instantaneous power profile generated by a particular technology cannot be directly injected into the grid for quality and stability reasons.

Power generated by a single point absorber WEC under real wave conditions

Therefore, a power conditioning stage is required to smooth the instantaneous power profile, especially in weak grids

Power oscillations to be integrated into the grid

- Sizing of the generators - Control strategies - Energy storage

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Contribution of hybrid energy and energy storage systems to the integration of variable renewable energy in the power system

CASE STUDY 1: Energy storage to compensate power oscillations from wave energy converters

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Contribution of hybrid energy and energy storage systems to the integration of variable renewable energy in the power system 5

Power generated and average power calculated

Power injected into the electric grid

Power provided or absorbed by the energy storage system during the operation

State of charge of the energy storage system during the operation

CASE STUDY 1: Energy storage to compensate power oscillations from wave energy converters

Contribution of hybrid energy and energy storage systems to the integration of variable renewable energy in the power system

Definition of the energy storage required

• Once analysed a variable power generation, the energy storage is defined by:

- Maximum power - Energy - Number of cycles per year - Deep of discharge - Time response

Sometimes one technology is able to cover all the

requirements

Some others is better to consider the combination of several

technologies

Hybrid Energy Storage

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Contribution of hybrid energy and energy storage systems to the integration of variable renewable energy in the power system

Find the «Best friends» technologies for each

application

Flywheels

Electric Doble Layer Capacitors (EDLC)

FAST ENERGY STORAGE SYSTEMS SLOW ENERGY STORAGE SYSTEMS

Upper reservoir

Lower reservoir

Reversible turbine

modified from Statkraft

Pumped storage

Batteries

Liquid Air Energy Storage (LAES)

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Contribution of hybrid energy and energy storage systems to the integration of variable renewable energy in the power system 8

Examples of hybridisation with fast energy storage

• Batteries + EDLC

• Adiabatic CAES + Flywheels ( Zhao et al., 2014)

• Pumped Hydro + Flywheels (Makarov, 2008; Lu, 2010; Jin, 2014)

Very extended in transport EDLC provide power while batteries energy

Some minutes are required while the system gets prepared

• Fuel cells + EDLC

Fast energy storage device provide the transient power peaks

Contribution of hybrid energy and energy storage systems to the integration of variable renewable energy in the power system 9

CASE STUDY 2: Hybridisation of pumped storage with fast energy storage

Benefits of pumped-hydro + fast energy storage (flywheels or EDLC) versus other solutions for pumped-hydro to provide power regulation (variable-speed, hydraulic short-circuit)

Use of fast energy storage reduces the power provided through interconnections of the grid, giving more sustainability to it

Use of fast energy storage increases the power response of hydro power systems

It improves dynamics in pumping mode as well as in turbine mode in the case of slow response of the needle valves of Pelton turbines

Contribution of hybrid energy and energy storage systems to the integration of variable renewable energy in the power system 10

Combination of energy storage technologies

Flywheels EDLC SMES Batteries

Pumped hydro

CAES/LAES

Thermal

Batteries

Fast Slow

Hydrogene

Contribution of hybrid energy and energy storage systems to the integration of variable renewable energy in the power system

• Fast power response • High power density • High number of operation cycles • High efficiency • Less dependance of the temperature

than other alternatives (batteries)

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The main barriers • High cost • Mechanical complexity

Technological Challenges • Increase the energy density • Improve the efficiency even more • Improve power electronics performance • Faster digital control devices

Characteristics of fast energy storage technologies

NAME TYPE OF ENERGY

ENERGY STORAGE FORMULATION

FLYWHEEL Kinetic energy EKES= ½ J ω2

EDLC Electrostatic

energy EEDLC= ½ CV2

SMES Magnetic

energy ESMES= ½ L I2

Contribution of hybrid energy and energy storage systems to the integration of variable renewable energy in the power system 12

How to decide the contribution of each technology in hybrid storage systems?

Basically, three rules: 1. Optimise power split 2. Minimise losses 3. Optimise State of Charge 4. Optimise Stat of Health

Under these rules are several concepts … 1. Instantaneous power limitations of each device 2. Time response of each device 3. Expected Tª increases due to power demands 4. Power losses minimisation 5. Number of cycles already accomplished

Algorithm

Power command A

Power command B

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CASE STUDY 3: Hybrid Energy Storage Systems for Hybrid Generation (SH2)

Hybrid generation = renewable + Diesel (isolated grid)

SH2

Combination of ultracapacitors with batteries to increase the life cycle of the batteries and

the system efficiency

Hybrid storage = batteries + ultracapacitors

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Conclusions

Integration of renewable energies in the electric grids requires energy storage, of many types, separated or together, to fit the grid codes

Hybrid storage increases the efficiency of the electric power system

Fast energy storage devices are a good combination with other types of storage since usually have complementary capabilities

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Course organised by CIEMAT - Different types of energy storage and

applications

- Participation of experts from different research institutes and Universities (CSIC, UPM, UAM, CNH2, IMDEA)

- Use of the unique experimental laboratories of CIEMAT to provide 25% of the time in experimental tests with prototypes and computer simulations

- Hybrid energy storage will be also covered by the course

More information: [email protected] Ph: +34 913466748

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Thank you for your attention

[email protected]