The future belongs to Renewable Energy Sources (RES), and
Satisfying the energy growing demand for sustainable energy
Sources must be one of the highest priorities for research in
The energy field. Four main electricity storage applications can
Be distinguished for RES management:
- Load leveling e to allow smoothing the RES power plant
Output (Fig. 1 left).
- Time shifting e to store electricity during low demand periods
And feed in the grid when demand is high and/or
Electricity prices high.
- Forecast optimization uses the storage system as a buffer
Enabling a real-time RES production as scheduled e for
Example in PV or wind 24 h’ forecasts (Fig. 1 right).
- Grid stabilization and system services: storage systems
Based on hydrogen can act as secondary and tertiary reserves
For grid frequency and voltage regulation
Hydrogen presents many advantages for storage of the
RES, in particular:
- PEM electrolyze are suitable for high dynamics from RES
E.g. wind and photovoltaic;
- High pressure electrolysis i.e. 35e50 bar allows the production
Of gaseous hydrogen and oxygen without further
Compression stage which implies lower investment costs
And higher simplicity of the system;
- H2 and O2 are both stored and used to produce electricity
Back in an H2/O2 fuel cell;
- O2/H2 fuel cells are air independent system and present a
Better output compared to Air/H2 fuel cells