The more fluctuating energy sources such as solar, wind and wave power are connected to a Smart Grid, the more complex and challenging will it be to ensure stable conditions. Supply and demand always have to be balanced electrically otherwise voltage and frequency fluctuations can affect the electronics of connected devices or even destroy them. For this reason, energy storage units play an important role in the Smart Grid concept of the Company. Meanwhile, various technologies are available that are capable of performing these tasks in the millisecond, minute or hour range.
The following figure shows an overview of the most common storage technologies for all performance classes:
Excess energy from wind, hydro and wave power can be transformed into energy-rich hydrogen using the so-called electrolyzer. Hydrogen can be stored intermediately in specialized tanks or underground and can be converted back into a variety of forms as and when required:
- Via gas turbine into electricity
- Via fuel cell into electrical and thermal energy
Via fuel cell into kinetic energy (Vehicles)
Pumped storage plants
Pumped storage plants have been successfully used as storage systems for unused band energy. At present, existing pumped storage plants are being modified worldwide in order to respond quickly to fluctuating energy.
By today’s findings, battery storage is better suited for absorbing and releasing fluctuating energy in the second and minute range.
Currently, there are the following systems:
- Lead-acid batteries
- Batteries with liquid electrodes
- Lithium-ion batteries
- Sodium-sulfur batteries