Two major sources of rapid frequency response
(RFR) to counter the reducing system inertia problem of the
Great Britain (GB) system are “synthetic inertia” from wind
turbines and fast demand response (FDR). In this paper, we
consider a future low inertia scenario to show the effectiveness
of RFR provision from the large offshore wind farms (OWFs)
planned in the North Sea (concentrated response) against FDR
from loads spread across the GB system (distributed response).
The spatial variation in transient frequencies, which can be
pronounced in the aftermath of a disturbance and is critical
for the response activation of these actuators, is accounted. Case
studies using a reduced GB system model show the effectiveness
of distributed FDR and concentrated support from OWFs in
providing RFR when disturbances occur in different areas of the
system where different inertia levels are present.