Introduction

Ultracapacitors, also known as supercapacitors, are energy storage devices that can store and deliver energy very fast and with a high efficiency. They are based on an electrostatic energy storage process, which takes place completely free of chemical processes, contrariwise to batteries that are based on electrochemical energy storage processes. They present a high energy and power density, are very secure and reliable for use in a wide temperature range, present a long lifespan and can be charged and discharged many hundreds of thousands of times without remarkable output loss.

Due to their outstanding advantages, ultracapacitors are already implemented worldwide in a multitude of different applications. Ultracapacitors thereby replace or complete a primary energy source such as a battery, a combustion motor or a fuel cell that is not designed for repeatedly delivering high amounts of power or managing transient events. Due to the sustained development of electrical systems and solutions in all sectors, the future for established high-performance energy storage technologies such as ultracapacitors seems very bright.

Where are ultracapacitors applied?

Primary energy sources such as combustion motors, batteries and fuel cells are at their most efficient when they are used as continuous energy sources. Limits are set when the application requires temporarily storing or delivering high amounts of power, for example because they can only be discharged and recharged slowly.

Ultracapacitors, however, are predestined for storing and delivering power spikes. They can store and transmit energy efficiently and quickly and thereby contribute avoiding energy losses. They are therefore an ideal addition to a primary energy source, although in some applications that require high amounts of power they can be used as the only energy source.
Ultracapacitors can be used in a variety of applications:

  • Electrical board net stabilisation, regenerative braking, start-stop as well as X-by-wire functions and other electrical systems in vehicles that temporarily require high amounts of power
  • Regenerative braking in hybrid vehicles
  • Mobile and stationary braking energy storage and drive support of rail vehicles and tram
  • Backup power of pitch systems in wind power plants
  • Reliable and efficient starting of combustion engines in all vehicles
  • Energy storage and peak load coverage for construction machines and cranes
  • Backup power for temporary UPS systems as well as starting of UPS diesel generators
  • Energy storage for voltage and frequency stabilisation in the energy network
  • Support for variable, intermittent power in case of energy generation from renewables
  • Peak load coverage for door opening systems, flap control, vents, etc.