Energy storage technologies for intermittent renewable energy systems S R Awasthi Dr. Pragya Nema Consultant, CECL, Bhopal Professor, Electrical Engineering Department Ex. General Manager, BHEL

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Energy storage technologies for
intermittent renewable energy systemsS R
Awasthi Dr. Pragya Nema
Consultant, CECL, Bhopal Professor,
Electrical Engineering Department
Ex. General Manager, BHEL Netaji
Subhash Engineering College, Kolkata (W.B.) 
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Contents

• Introduction
• Background of storage system
• Different energy storage technology
• Comparison of different storage technology
• Conclusion

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Introduction

• What is energy storage system for renewable
  energy ?
• Why is it required ?
• Function of energy storage system

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Background of storage system

• Storage is an essential unit that stores
  unstable electric energy during wind and
  photovoltaic power generation, which is sharply
  growing new renewable energy, and supplies the
  unstable energy to electric power system again in
  necessary moment. If there is no such energy
  storage unit, any kinds of serious problems like
  sudden blackout occurs because of unstable
  sunlight-dependent electricity supply. This
  Storage takes an important part in the
  electricity storage systems for households, the
  medium-size system for industrial/commercial use,
  and the extra-large system for power plants and
  substations like Frequency Regulations

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different Energy storage technologies

• Pumped storage
• Batteries
• Superconducting magnet energy storage
• Flywheel energy storage
• Regenerative fuel cell storage
• Compressed air energy storage

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Pumped storage

• A pumped storage hydro power plant may store huge
  energy by pumping water from a lower reservoir to
  a higher pond. In a pumped storage hydro plant,
  we usually make the height of the reservoir equal
  to a small hill and at bottom a cavity is made so
  that water may not run away downward.
• Water is pumped during off-peak times and may be
  utilized to generate electricity. Other
  innovations may store electricity in small
  quantity but pumped storage hydro power plant may
  store electricity in Megawatts (MW) or even
  Gigawatts(GW).

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Batteries

Battery
Battery working
Battery Bank
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Flywheel energy storage

• Flywheel energy storage systems are one of energy
  storage devices. They store energy mechanically
  in the flywheel rotor by rotating the rotor while
  as chemical batteries stores energy electrically.
  When we want to use the stored energy in the
  rotor, a generator is used to convert mechanical
  energy to electrical energy.
• Flywheel systems are not sensitive to temperature
  since they are operating in a vacuum containment.
  Therefore, the hybrid vehicle with flywheel
  systems can run without any problem at very cold
  or hot areas. And, flywheel systems can store
  more energy per system weight compared to
  chemical batteries,
• The flywheel system is a very efficient energy
  storage device, it can be used for various
  applications.

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Superconducting magnet energy storage

• Superconducting magnetic energy storage systems
  store energy in the magnetic field created by the
  flow of direct current in a superconducting coil.
  This advanced systems store energy within a
  magnet and release it within a fraction of a
  cycle.

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Regenerative fuel cell storage

• A fuel cell is an electrochemical cell that
  converts a source fuel (from combustible
  substances such as hydrogen, methane, propane,
  and methanol) into an electric current.
• A fuel cell is a device that generates
  electricity by a chemical reaction. Every fuel
  cell has two electrodes, one positive and one
  negative, called, respectively, the anode and
  cathode. The reactions that produce electricity
  take place at the electrodes.
• Hydrogen is the basic fuel, but fuel cells also
  require oxygen. One great appeal of fuel cells is
  that they generate electricity with very little
  pollutionmuch of the hydrogen and oxygen used in
  generating electricity ultimately combine to form
  a harmless byproduct, namely water.

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Compressed air energy storage
continue

• Energy from solar or wind and even electricity
  from thermal power plant during off-peak period
  may be utilized to compress air by compressor and
  same air may be utilized to produce electricity
  during peak-hour.
• Compressed air energy storage is done in
  underground caverns and abandoned mines.

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References

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