This document discusses various types of energy storage systems. It introduces renewable energy sources that have intermittent generation profiles, creating supply and demand discrepancies. Energy storage enables electricity production at one time to be stored and used later to meet peak demand. The document then summarizes different types of energy storage technologies including batteries, mechanical storage, compressed air, pumped hydro, hydrogen, and flywheels. It discusses the workings, efficiencies, lifecycles and issues with each technology. The document concludes that energy storage solutions are important for balancing the grid but require further research and development of policies and public-private partnerships.

1. PREPARED BY:
GAGANDEEP KAUR
ASSISTANT PROFESSOR
CCAE, CHITKARA UNIVERSITY

2. INTRODUCTION
➢ It is particularly important for the development and integration of renewable energy
technologies. Some renewable energy sources have intermittent generation profiles, which
means that electricity is only produced when the sun is shining or when the wind is blowing. This
creates supply and demand discrepancies because consumers may still require electricity when
renewables sources are not producing.
➢ Energy storage enables a lower-cost generating source to produce electricity at a different point
in time to be stored and then used to meet times of peak demand. This ‘flexibility' has the
potential to transform how we produce and consume electricity.

3. ENERGY STORAGE SYSTEM
➢ Energy storage system can actually store energy and use the stored energy whenever the need
arises.
➢ As the need for clean energy arises, the need to replace current existing power plants have
become a global issue.

4. NEED OF ENERGY STORAGE
➢ Supply and Demand mismatch
➢ Utilize storage for peak periods.
➢ Reliable power supply.
➢ Reduce the need for new generation capacity.
➢ Electrical vehicles
➢ Emergency support.

5. TYPES OF ENERGY STORAGE
➢ Energy storage systems are the set of methods and technologies used to store various forms of energy.
➢ There are many different forms of energy storage
• Batteries: a range of electrochemical storage solutions, including advanced chemistry batteries, flow
batteries, and capacitors
• Mechanical Storage: other innovative technologies to harness kinetic or gravitational energy to store
electricity
• Compressed Air: utilize compressed air to create energy reserves. Electricity can be converted into
hydrogen by electrolysis. The hydrogen can be then stored and eventually re-electrified.
• Pumped hydro-power: creates energy reserves by using gravity and the manipulation of water elevation
• Thermal: capturing heat or cold to create energy
➢ The choice of energy storage technology is typically dictated by application, economics, integration within
the system, and the availability of resources.

6. BATTERY ENERGY STORAGE SYSTEMS (BESS)
➢ BESS for PV systems: DC/DC converters are used
Providing DC link voltage to the inverter from
battery.
➢ BESS for Utility: Bidirectional Inverter (DC/AC
or AC/DC) are used. DC/AC conversion to AC
grid and AC/DC conversion to charging battery
Efficiency of BESS is between 65 to 95% depending upon the type of battery.
Limited Life cycle.

7. HYDROGEN ENERGY STORAGE SYSTEMS (HESS)
➢ Hydrogen as fuel
➢ Electrolyser : Decomposing water to H and O2 then H stored in a high pressure tank as fuel storage
➢ Fuel cell: generating DC power by reaction of H and O2 and Water or steam released as waste
➢ Hydrogen able to be transported via gas pipes
➢ Overall HESS around 30% efficiency which is much lower than BESS

8. PUMPED HYDRO STORAGE (PHS)
➢ Employs off peak electricity to pump water to
a reservoir of low elevation to higher elevation
and run down to hydro turbine to generate
electricity..
➢ Can be sized upto 1GW.
➢ Efficiency 80-85%.
➢ Life 50-60 years.
➢ Siting issue
➢ Expansive to build.

9. PUMPED HYDRO STORAGE PLANTS IN INDIA

10. COMPRESSED AIR ENERGY SYSTEM (CAES)
➢ Air is compressed ad stored and is later used in gas turbine stations.
➢ Can be sized underground 400 MW. Above ground 3-50 MW.
➢ Efficiency 70%.
➢ Life 30 years.
➢ Siting issue.
➢ Expansive to build.

11. MECHANICAL ENERGY STORAGE SYSTEM (MESS)
➢ Flywheels
➢ Energy is stored in the form of mechanical
energy.
➢ Life 20 years.
➢ Efficiency 70-80%
➢ As most energy is lost due to friction flywheels
are operated in enclosed vacuum space.
➢ Low environmental impact.
➢ Suitable for shorter duration
➢ High cost.
➢ Add more weight to cars.

12. STRATEGIC APPROACH

13. BARRIERS

14. CONCLUSIONS
➢ ESS for balancing grid is a long term solution.
➢ Research centers should be established to carry out the research and for testing in this
field.
➢ Countries who have not yet explored their renewable energy potential should explore
potential of storage in parallel.
➢ Proper policies should be developed.
➢ Explore public private partnership

15. “Energy earns or simply burns, choice is yours.
Energy misused cannot be excused.”