The present UK distribution network planning standard,
Engineering Recommendation P.2/6 (P2/6), defines the
acceptable durations of supply outages following first and
second circuit outage conditions as function of group demand.
In addition, P2/6 specifies a capacity value for distributed
generation (DG) to be used in future circuit capacity planning.
The approach does not consider other elements of the
distribution network. This paper analyses the reliability
performance of distribution system when DSR is used to
defer network upgrades driven by load growth. The analysis
uses actual DSR performance data from trials that were
executed as part of the Low Carbon London project. The DSR
contribution to security of supply is assessed using a
probabilistic risk modelling framework to further inform a
number of topics (i) reliability contribution of DSR
technologies in a network context, (ii) strengths and
weaknesses of P2/6 in estimating contribution to security of
supply, (iii) benefits of contractual redundancy, (iv) impact of
DSR coincidence in delivery (common mode failures) on
contribution to security, and (v) impact of DSR scale and
magnitude on contribution to security of supply.