Definition of storage
The general definition for storage is: Storage is the result of an action or method of storing or buffering something – and most importantly – for future use.
There is a variety of Energy Storage (ES) systems. The majority of systems are so called power-in-power-out type of solutions. E.g. batteries fall into this category.
Other ES solutions convert electricity into another form of energy, e.g. gas (Power-2-X), which then can either be stored, transported or packaged in smaller units e.g. gas bottles.
ETES (Electro-Thermal-Energy-Storage) from MAN Energy Solutions is different. It’s a tri-generation solution. Means, ETES is providing three forms of energies – heat, cold & electricity. In charging mode – working like a heat pump – ETES converts electricity into heat and cold, which can be utilised directly or being short-term stored for future usage.
ETES is also a huge battery if you wish. Because in discharge mode, when the system partly runs in reverse, it re-generates electricity on demand out of the stored heat and cold. The round trip efficiency is about 50% up today.
This works in a most environmentally friendly manner by reducing CO2 and supporting the decarbonisation process at large.
ETES is not a one way or the other energy storage system like batteries. It offers unbeaten flexibility by providing three different types of energy, plus the most scalable storage with up to several hundreds of MWhours a day.
The role of storage between utilities and grid operators (unbundling)
Energy storage is most likely becoming the most crucial but still widely neglected missing piece of infrastructure, in order to stabilise and secure energy supply. It is mindless to further deploy renewables (wind & PV), without investing in energy storage accordingly.
Why? Because renewable power from wind and solar is already causing imbalances on the grid today. And this will only be accentuated by increasing renewables, unless investments in energy storage start to catch-up.
Secondly, every form of energy, which is or could be generated, but is not utilised or stored, is lost and so wasted for all times. Energy storage is the only method to inhibit this at current.
But one must think big. Very big!
Incentives for grid-relieving operation of storage systems?
Energy storage gives flexibility. And flexibility is an asset. Energy storage is indeed the most appropriate instrument for grid balancing. It not only would help grid operators and other energy suppliers to avoid or at least diminish payments for minus tariffs (grid balancing / peak shaving).
Energy storage very much also can secure the continuous power supply – means no intermittencies – despite further deployment of renewables (wind / PV).
Both arguments inherently deliver a good business case to make it attractive for energy suppliers and the governments to invest and consider energy storage more.