Whole energy system modelling is a valuable
tool to support the development of policy to decarbonise
energy systems, and has been used extensively in the UK for
this purpose. However, quantitative insights produced by
such models methods necessarily omit potentially important
features of physical and engineering reality. The authors
argue that important socio-technical insights can be gained
by studying critical events such as the loss of 2.1 GW
generation from the electricity system of Great Britain in
August, 2019. The present paper uses this event as a starting
point for a discussion of the need for additional tools, drawn
from the System Architecture literature, to support the
design and realisation of future fully decarbonised systems
with high penetrations of renewable energy, capable of
providing high levels of resilience and flexibility