Background to UK Energy Storage

Energy Storage is fast becoming essential to provide a constant and balanced delivery of energy into the national grid

The U.K. Government acknowledges that energy storage systems (ESS) provide an opportunity to diversify the way we use available power and deliver it effectively By storing excess energy when it is generated and releasing it when it can be used, it will be possible to make the existing grid network more robust and sustainable in the long-term.

UK Renewable Min

UK Renewable Max

2020 UK Renewable Goal

Intermittent renewable energy already accounts for over 20% of the UK’s electricity, and at some times this rises to over 50%. The proportion of electricity from these sources, combined with electricity from new wave and tidal sources, is set to increase to 24% by 2020 to meet EU renewable energy targets (Source: Parliamentary POST note 464 May 2014 Intermittent Electricity Generation).

As a nation, we are moving away from coal and gas burning power plants and replacing them with renewable energy sources. However, most forms of renewable electricity generation are deemed as disruptive due to their variability and intermittency.

Advances in battery technology and materials have greatly increased the reliability and output of modern battery systems, and economies of scale have dramatically reduced the associated cost. Continued innovation is creating new tools such as electrochemical capacitors which can be charged and discharged simultaneously and instantly, to provide an almost unlimited operational lifespan. Advances in battery technology continue apace.

The Energy Storage System (ESS) favoured by Immersa is based on lithium ion (Li-ion) batteries. Li-ion storage is a proven technology which has already been deployed globally in a wide range of ESS applications.

How Battery Systems Work

There are many different types of battery eg.

  • Lead acid (found in most petrol or diesel vehicles)
  • Lithium ion or “Li-ion” (found in many electronic devices)
  • Nickel-cadmium (typical rechargeable household battery)
  • Metal ion flow batteries (mostly contains metal ions dissolved in water)

All rely on the flow of charged atoms or molecules called ions through a liquid or solid “electrolyte” medium. The ions transport electrical charge in a controlled manner to and from a negatively charged terminal and positively charged terminal. When the battery is supplying power, these ions release a “flow” of electrons at the negatively charged terminal, which is an electrical current.

Highly responsive battery systems can react within milliseconds to a request to charge or discharge. Battery systems with a high reserve can provide power over extended periods on a larger scale. Batteries can be joined together ie modularised into banks in order to provide large amounts of power. Hundreds of individual batteries can be stored in 20-40 foot shipping containers which can be located inside or outside buildings. Typically these systems can completely charge or discharge within one hour, and are now being deployed in the UK to balance the National Grid.

The battery systems connect to the grid through an “inverter”, which converts the direct current leaving the battery into 50 Hz alternating current used in the UK and European grids. The inverter works in reverse when the battery system is charged using grid electricity.

Battery systems can be installed ‘in front of the meter” (grid balancing only systems) or on the grid side ie ‘behind the meter’ which allows industrial and residential users to store energy generated by on-site solar panels/other renewables before it is exported to the grid. These systems can generate income by selling electricity to the grid at times of peak demand.

Immersa can help you install a battery system suitable for your needs.

Contact Us to Find Out How