Energy storage technologies


Since the discovery of electricity, we have sought effective methods to store that energy for use on demand. Over the last century, the energy storage industry has continued to evolve, adapt, and innovate in response to changing energy requirements and advances in technology.


New quarterly report out June 18


Storage means reduced costs, resilience, flexibility, and security.

A wide array of storage technologies have been developed so that the grid can meet everyday energy needs.

Energy storage systems provide a wide array of technological approaches to managing our power supply in order to create a more resilient energy infrastructure and bring cost savings to utilities and consumers.

To help understand the diverse approaches currently being deployed around the world, we have divided them into five main categories:

  • Batteries: a range of electrochemical storage solutions, including advanced chemistry batteries, flow batteries, and capacitors
  • Thermal : capturing heat and cold to create energy on demand or offset energy needs
  •  Mechanical Storage: other innovative technologies to harness kinetic or gravitational energy to store electricity
  • Hydrogen: excess electricity generation can be converted into hydrogen via electrolysis and stored
  • Pumped Hydropower: creating large-scale reservoirs of energy with water


The contributions of a number of scientists and innovators created our understanding of the forces of electricity, but Alessandro Volta is credited with the invention of the first battery in 1800. On its most basic level, a battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy.

Thermal energy storage

Modern solar thermal power plants produce all of their energy when the sun is shining during the day. The excess energy produced during peak sunlight is often stored in thermal energy storage facilities – in the form of molten salt or other materials – and can be used into the evening to generate steam to drive a turbine to produce electricity.

Mechanical energy storage

Mechanical energy storage systems take advantage of kinetic or gravitational forces to store inputted energy. While the physics of mechanical systems are often quite simple (e.g. spin a flywheel or lift weights up a hill), the technologies that enable the efficient and effective use of these forces are particularly advanced. High-tech materials, cutting-edge computer control systems, and innovative design makes these systems feasible in real-world applications.

Pumped hydropower storage

Gravity is a powerful, inescapable force that surrounds us at all times – and it also underpins one of the most established energy storage technologies, pumped hydro-power. Currently the most common type of energy storage is pumped hydroelectric facilities, and we have employed this utility-scale gravity storage technology for the better part of the last century in the United States and around the world.

Hydrogen energy storage

Electricity can be converted into hydrogen by electrolysis. The hydrogen can be then stored and eventually re-electrified. The round trip efficiency today is lower than other storage technologies. Despite this low efficiency the interest in hydrogen energy storage is growing due to the much higher storage capacity compared to batteries (small scale) or pumped hydro and CAES (large scale).

Become a Member

Elevate Your Business with Insider Access:

  • Policy Direction: Your voice in critical industry discussions.
  • Exclusive Networking: Learn directly from key players in clean energy.
  • Insider Information: First-hand access to policy insights and premier events.
  • Advanced Tools: Our proprietary data at your fingertips to drive growth.

Act now to become a defining part of clean energy’s future.

Stay informed

Take Action

Subscribe to American Clean Power and receive the latest clean energy news, policy updates, and opportunities to get involved.