Interactions between demand side response, demand recovery, peak pricing and electricity distribution network capacity margins

Abstract

The operation of the electricity system is subject to: charges comprised of energy, capacity, use of system, peak demand and balancing components; payments for services that influence the timing and magnitude of demand; and regulatory and physical network constraints. This work explores the interactions of these characteristics in the GB system. The revenue flows associated with energy demand, balancing and use of system charges are mapped for generators, transmission and distribution network operators (TNO and DNOs), system operator (SO), electricity retailers and electricity users. Triads are part of the transmission network use of service charges and are a form of peak demand pricing. The cost-benefit of Triad avoidance using emergency standby generation is evaluated. Demand Side Response (DSR) provision by commercial electricity users on the network is modelled and simulated. The research determines the impacts of DSR timing, location and penetration level, demand recovery and incidence of Triad periods. A suite of software models was developed including: network demand agents which can be populated with demand profiles and include a model of energy recovery; an interface to Matpower [1] to allow for time-domain based power flow calculations and a model of Short Term Operating Reserve (STOR) which synthesizes calls at representative dates and times. The network demand agents are linked to bus-bars on a network model. The software suite is used to investigate the impacts of STOR provision by demand reduction with and without energy recovery on Triad demand using a Monte Carlo simulation. The total cost benefit of participation in STOR is evaluated. It is also used to conduct timeaware power-flow analysis on a distribution network model with STOR provision by demand reduction. The impact on network capacity headroom is quantified. The cost effectiveness of using standby generation for Triad avoidance was found to depend on the cost of the grid compliant connection. For a payback time of 4 years or less, with the size of generator considered, the grid compliant connection would have to cost less than £5,600. The probability of decreased Triad demand due STOR provision by demand reduction with energy recovery is up to 4 % for the parameters considered. This compares to a probability of up to 1.6 % that the Triad demand would be increased. The most likely outcome is that Triad demand remains unaffected. The total cost benefit of STOR Abstract 2 provision by demand reduction for the 1st percentile may be negative compared to not participating. The impact of DSR provision by demand reduction with energy recovery on the distribution network capacity overhead varies significantly with time of day and with the distribution of DSR over the network. For evenly distributed DSR, demand recovery peaks greater than 40 kW cause a reduction in capacity overhead. However, for a case where the DSR is not evenly distributed the capacity overhead does not decrease for recovery peaks less than 800 kW.