A power plant with storage but without fuel or exhausts for smoothing ‘green’ electricity

In the following, RePowerBuf is presented, which is a new concept for filtering and backing electric power to counteract fluctuations from renewables. It can also be used as system-relevant residual power plant in the 100 MW/16.8 GWh range for the transition to renewable energies. It provides for a controlling power range in time scales of one week to 10 ms, operates in all four quadrants of the complex Gaussian plane, filters harmonic components of the line frequency by the mass inertia of its generator and by fuel cells and Li-Ion accumulators as backing systems, augments the short-circuit capacity of the grid, reduces thus its internal resistance, and contributes to its frequency stability. This is accomplished without consuming fuel or polluting the environment by means of closed Power-to-Gas-To-Power Loops.