The R&D project is likely to become an international model for a long-term sustainable smart grid and the island’s consumers are reaping the benefits of it being easier to save on energy bills and sell excess electricity.
The project was initiated in July 2010, when ABB and Vattenfall / GEAB signed an agreement to lead the development of future energy systems, building on several collaborations between ABB and Vattenfall in the power sector.
It combines advanced technologies that enable integration of renewables and maintains reliability of the grid as a whole. Technologies such as smart meters, smart control, energy storage, IT and communication technology, and smart SCADA (supervisory control and data acquisition) will all be integrated and evaluated.
Control and communication
A smart grid control centre sits at the centre of the grid and takes an overview of the operation and monitoring of the grid. Unusually for a SCADA system, the project’s smart SCADA controls the low voltage network and demand response as well as the medium voltage network. At the control centre, the grid’s activities are monitored and recorded to research the safe introduction of new grid applications.
An extensive information and communication network links every installation, enabling monitoring and control of the grid.
ABB’s software business Ventyx is deploying a comprehensive solution for Distribution System Optimization. This will encompass network control, demand response management, demand forecasting and business analytics to support the project. Distribution management system software supplied by Ventyx will be integrated with ABB hardware and will address bottlenecks in the distribution network that may restrict the flow from the wind turbines to consumers.
Upgrading the distribution grid
By using state-of-the-art substation equipment, the higher capacity substations maintain a compact footprint and have minimal environmental impact.
An upgraded distribution system enables advanced control and monitoring of low and medium voltage systems. This includes last-mile-SCADA and will improve grid management and improve the ability to integrate renewable energy. Substations have been reinforced with the latest technology to handle the increase in power from wind generators.
Energy storage plays an important role in the system by actively balancing production and loads. A battery energy storage facility works in combination with a static VAr compensator (SVC).
Together, these support the introduction of additional wind power generation. The battery overcomes peaks and troughs in supply and demand, as well as grid regulation, and supplies up to 3.6 MW for five minutes. The SVC has the role of controlling active and reactive power that is injected into or retrieved from the system.
A major element of the project is in how it involves consumers and the community as a whole. The smart grid has been actively recruiting customers to participate in the project.
Around 3,000 consumers will be fitted with smart meters, giving real-time surveillance of the low voltage grid and measuring energy consumption, power quality and outages.
Demand response is also an essential element of Gotland’s smart grid. Around 2,000 households and 20 – 30 industrial customers will be recruited to a sub-project to test the market conditions of the smart grid. The consumers will be equipped with an Energy Service Interface (ESI), a product that reads electricity price signals and enables them to switch loads on and off.
This will link renewable energy generation with consumer demand, using structured tariffs to encourage highest use of energy when the supply is strongest.
Another important aspect is the Reference Group for the Smart Grid Gotland project. Bringing together representatives from government agencies and interest groups, the group acts in an advisory capacity and as a vital link between the smart grid and the business community.
The project has brought together strategies to plan, build and operate a fully developed large-scale smart grid. It is helping Sweden fulfil its climate targets and is likely to become an international model for a long-term sustainable electricity power system.
In early 2014, the Swedish Energy Agency approved the funding for the second phase of the Smart Grid Gotland project. This represents the development of a self-healing grid. The existing distribution network will be divided into smaller sections. In the event of faults, the self-healing network will re-route power to minimise the number of customers affected by an outage.