Energiasalvestust

Energiasalvestust is the Estonian term for energy storage, referring to systems and methods that capture energy at one time for use later. It encompasses electrical, thermal, chemical, and mechanical forms of energy and enables generation to be decoupled from consumption, supporting reliability and flexibility in energy systems.

Major categories include mechanical storage (pumped storage hydropower and compressed air energy storage); electrochemical storage (batteries such as lithium‑ion and redox flow batteries); thermal storage (sensible or latent heat and molten salts); chemical storage (hydrogen and other fuels produced by electrolysis); and biological or chemical energy storage (biofuels).

Key metrics describe how energy storage is evaluated: energy capacity (how much energy can be stored), power rating (rate at which energy can be delivered), round‑trip efficiency, cycle life, response time, and levelized cost of storage. Designers trade off duration, energy density, and cost to fit a given use case.

Technologies range from large‑scale pumped hydro storage, which accounts for a large share of installed grid storage capacity, to stationary batteries for near‑term grid services, and to long‑duration options such as hydrogen storage. Emerging approaches include solid‑state and flow batteries, and thermal storage paired with electricity or heat networks.

Applications include grid balancing, renewable energy integration, peak shaving, backup power, and energy needs for portable devices and electric vehicles, all of which benefit from the ability to store excess energy and release it when needed.

Challenges involve high upfront costs, material supply constraints, environmental and land‑use impacts, safety considerations, and the development of recycling and policy frameworks to support deployment. Ongoing research aims to improve density, durability, and cost, with long‑duration storage playing a key role in decarbonization.