Electrical energy storage

Energy storage is a crucial technology for the integration of intermittent energy sources such as wind and solar and to ensure that there is enough energy available during high demand

Building resilience into the grid

To avoid electricity fluctuations (brownouts) or the complete shutdown of electricity supply (blackouts), exactly the right quantity of energy needs to be generated, not more, not less: this is called balancing the grid. At times of high electricity demand, extra capacity must be immediately available or the grid risks shutting down. One way of ensuring continuous and sufficient access to electricity is to store energy when it is in surplus and feed it into the grid when there is an extra need for electricity. 


  • EES systems maximize energy generation from intermittent renewable energy sources.
  • maintain power quality, frequency and voltage in times of high demand for electricity.
  • absorb excess power generated locally for example from a rooftop solar panel. Storage is an important element in microgrids where it allows for better planning of local consumption. 


They can be categorized into mechanical (pumped hydro), electrochemical (secondary and flow batteries), chemical (including fuel cells), electrical and thermal systems. Utility-scale storage capabilities are still mainly reliant on pumped hydro but batteries are increasingly used as their energy density (energy storage capability) increases and costs are coming down. 



Electric vehicles: a big potential


In coming years, electric vehicles (EVS) which are connected to the grid could be used instead of or in conjunction with other EES systems in emergencies or during extreme supply shortages, to deliver power to the grid. Leveraging a two-way flow of electricity from EV battery storage to balance power supply and demand could also help global efforts to integrate more renewables in the power mix. EVs can charge when renewable energy generation from wind or the sun is high or when there is lower demand for electricity ( e.g. when people are sleeping). 



IEC work for EES
Several IEC technical committees (TCs) prepare international standards relevant to EES:

Publishes standards covering storage pumps used in pumped-storage hydro power plants

Issues documents for all secondary cells and batteries, including for renewable, on-grid and off-grid energy storage

Establishes the specifications for energy storage systems using electrodes and electrolytes (capacitors) 

Develops standards for fuel cell technologies

Covers all types of EES technologies in a systems-based approach

Prepares standards relating to EVs including for the management of charging infrastructure

Is one of the four Conformity Assessment Systems administered by the IEC


Electrical Energy Storage

The need for electrical energy storage (EES) will increase significantly over the coming years. With the growing penetration of wind and solar, surplus energy could be captured to help reduce generation costs and increase energy supply.

IEC work for energy storage

You will find in this brochure a selection of articles from our magazine, e-tech, on the work of IEC for energy storage.

IECEE: Batteries, chargers and charging stations

Batteries are used in millions of devices. This brochure explains the IECEE Conformity Assessment Scheme for testing and certification for safety and performance for batteries, chargers and charging stations.
More information

IEC is paving the way for these new technologies by developing and publishing a wide number of standards.

Electricity generating capacity is expanding to meet growing worldwide demand.

Renewable energies represent a fast-growing percentage of electricity generation.

Nuclear power plants (NPPs) produce an important proportion of the world's electricity. 

Storing energy is becoming ever more important as our demand for electricity increases.

IEC is forging a path for this global transformation with the required international standards.

Distributed energy resources are a way of increasing energy efficiency and improving grid resilience.

Getting clean and modern electricity to those who need it the most with the help of the IEC.

One of the most important ways of helping us to save energy is by implementing energy efficiency measures.

Renewable energy generates direct current and we use direct current in our homes to power many of our devices, from LED lights to mobile phones.

IEC publications help them to meet the various technical challenges they unavoidably face moving forward.