Increasing renewable penetration on islanded networks through active network management: a case study from Shetland

The drive to reduce reliance on fossil fuel generation in meeting power system demand is encouraging network operators to develop new methods managing network capacity while maintaining stability and security. Challenges relating to network stability are particularly acute on islanded networks. The Northern Isles New Energy Solutions (NINES) project is implementing techniques to manage the power network on the Shetland Islands in the UK. Active network management (ANM) is used to monitor and control generation in real time, and flexible demand is scheduled to minimise the use of conventional generation by reducing wind curtailment and minimising system losses. The flexible demand has the ability to respond to frequency and support system stability. This study presents the development of two modelling techniques used in the design and deployment of NINES - an `envelope of stability wind generation´ and the use of dynamic optimal power flow to schedule flexible demand. A case study is presented which shows that an ANM scheme managing flexible demand has the potential to increase wind capacity connected on Shetland from the existing 4 MW to 16.1 MW. Demand flexibility is shown to be capable of contributing up to 16.6 GWh towards reducing conventional generation.