Management of variable electricity loads in wind – Hydrogen systems: The case of a Spanish wind farm

The main obstacles of most renewable energies are their variability and availability; thus, we propose the ‘hydrogen option’ as a means of energy management, and we study its feasibility in a specific wind farm. The installation will be capable to store electrochemically the surplus energy and return the electricity to the grid during the peak hours. The solution was to connect the system, so that we store the energy as hydrogen when the wind generation exceeds a threshold; this is done by an electrolyzer set, with the appropriate nominal power, where, besides the electrical conversion devices, we have designed a control programme for tuning the voltage and current densities to the optimal operation of the cells. To utilize the hydrogen downstream the storage subsystem, we have selected a fuel-cell and the output is finally converted to the grid requirements.The nominal power of the wind farm studied is 48.8 MW, and it generates 18.4% of surplus electricity which cannot be evacuated through the node during the off-peak hours; this is converted into nearly 13 GWh of hydrogen per year, which can be used to produce peak electricity (raising the power of the hybrid system to 12.3%). Thus, it presents many advantages, which could facilitate the penetration of the wind resource, leading to a cleaner energy production and moving one step forward to the ‘hydrogen economy’.