  The power from wind and solar exhibits a nonlinear flickering variability,
which typically occurs at time scales of a few seconds. We show that
high-frequency monitoring of such renewable powers enables us to detect a
transition, controlled by the field size, where the output power qualitatively
changes its behaviour from a flickering type to a diffusive stochastic
behaviour. We find that the intermittency and strong non-Gaussian behavior in
cumulative power of the total field, even for a country-wide installation still
survives for both renewable sources. To overcome the short time intermittency,
we introduce a time-delayed feedback method for power output of wind farm and
solar field that can change further the underlying stochastic process and
suppress their strong non- gaussian fluctuations.
