The Shetland-based Northern Isles New Energy Solutions (NINES) project has demonstrated that an islands-only electricity distribution system can operate securely with a high penetration of local renewable generation.
The five-year £18 million project trialled domestic demand side management (DSM) and large scale energy storage solutions, combined with new monitoring and control systems to manage the electricity network on the islands.
Together, these elements made up one of the most advanced active network management systems in the world. Thanks to the learnings gained from NINES, similar systems are being rolled out elsewhere to help the transition towards low carbon networks and realise smart grids.
The findings from the NINES project have shown that greater volumes of renewable generation can be connected to a distribution electricity network by using ‘smart’ technology to manage how and when the energy is used, while maintaining system reliability and safety.
For example thanks to the ANM more than 8.545MW of new renewable energy has been connected on Shetland – which represents a trebling of renewable energy capacity on the islands.
As part of the NINES project, five renewable generation schemes were given a managed connection through the ANM system. This connection controlled when and how much each scheme could generate according to the prevailing network conditions on Shetland at any given time.
The last of the generators were connected in Spring 2017. While the impact is only just beginning to be felt, the daily average of renewable generation on Shetland is already reaching 30% of energy requirements. This is a significant increase from before the NINES project and the percentage has the potential to go even higher.
The installation of a 1-MW battery at Lerwick power station was used to help to provide a stable electricity network and to reduce demand peaks.
In addition to this, by working with Shetland based Hjaltland Housing Association, new storage heaters and hot water tanks were installed, along with communication devices to provide DSM capability in 234 households.
The battery stored the renewable generation at times of low demand so it could be used at a time when it was needed to supply people with electricity or heat. When operated through the ANM this combination of storage and DSM has directly resulted in the reduction of diesel used at the station by about 10%.
The battery worked in collaboration with the ANM system, which was the first of its kind in the UK. The ANM identifies when energy demand is high and what available energy there is in storage. It will automatically rebalance the network to make sure people receive the electricity they need.
The same is true if there is low demand but lots of renewable energy created. It will send that energy into the storage systems, to wait until it’s required. If there is not enough energy being generated or in storage it will then automatically call on thermal generation to help balance the system.
Stewart Reid, Head of Asset Management and Innovation at SSEN – which co-ordinated the project – said: “The project’s findings will be crucial to the wider-GB electricity network as it transitions to a low carbon economy and the greater adoption of renewable energy sources at a local community level, such as solar panels.
“By creating flexible demand on the islands, through the use of smart technology and energy storage, we have made progress in exploiting and maximising Shetland’s renewable generation potential and reducing the generated output from thermal power stations.
“This was an important achievement as it will inform the transition to a low carbon economy. It also offered us the opportunity to trial the technology in an environment which could then be applied to the wider-GB electricity network.
Paul Leask, Head of Asset Management and Investment, Hjaltland Housing Association, said, “Being a part of the NINES project gave us the opportunity to improve the energy efficiency of our housing stock and also making the local grid more responsive, which in turn allowed more renewables to connect.
“This project has enabled us to meet the Scottish Government Energy Efficiency Standards for Social Housing (EESSH) well in advance of the compliance year of 2020 and has provided our tenants with the opportunity to reduce their energy bills with more controllable heating and hot water systems.”
The NINES project partners also included, Glen Dimplex, Strathclyde University, Airwave Solutions and S&C.
Reid added: “This participation has not only served to reduce peak demand on Shetland, it has also allowed a higher utilisation of renewable energy. There is significant roll out potential in the UK with over 2.2 million homes currently using electrical heating systems, which could adopt similar technology.”