Trading on NODES in sthlmflex has now concluded for the winter 2020/2021 season.

sthlmflex is a research and innovation project that pilots a flexibility market to address the capacity challenges in the Stockholm area in Sweden. The project is led by the national transmission system operator (TSO) Svenska kraftnät (SvK) and two regional distribution system operators (DSOs) Vattenfall Eldistribution and Ellevio. NODES acts as an independent market operator.

A number of market solutions were trialled successfully this winter – some for the very first time. This winter’s trial included that:

• The DSOs purchased flexibility in NODES’ near term, continuous market (NODES’ ShortFlex market) on a day ahead and intraday basis. This featured two innovative elements.
• First, the two DSOs purchased flexibility in each other’s network areas. (Vattenfall Eldistribution own and operate two network regions to the North and South of Stockholm. Ellevio operates a third network region, in central Stockholm.) This worked through an exchange of transmission capacity subscription for each region (in Swedish “abonnemangsväxling”). For example, if Vattenfall Eldistribution purchased flexibility from a resource located in central Stockholm to fill a need in its region North of Stockholm, Svk lowered Ellevio’s transmission capacity subscription for central Stockholm and increased the subscription for Northern Stockholm. This meant that the DSOs could make use of flexibility resources located in either DSO’s network regions, with the price of flexibility resources across all three areas competing.
• Second, the DSOs used the ShortFlex market to activate temporary increases to the transmission capacity subscription held with Svk (“temporary subscription” or in Swedish “tillfälligt abonnemang”, see clarification of this term below). This meant that the DSOs used the ShortFlex market to compare the price of activating ”temporary subscription”/”tillfälligt abonnemang” issued by Svk with the price of flexibility offered by flexibility service providers and to purchase the cheaper alternative first.
• The DSOs activated existing long term availability agreements via the ShortFlex market through NODES’ functionality for availability agreements (NODES’ LongFlex functionality). This enabled the DSOs to compare the activation price of long term contracts with the price of flexibility offered in the ShortFlex market and to make use of the lower priced option first.
• NODES ran Sweden’s first tendering process to enable Vattenfall Eldistribution to tender for a new LongFlex agreement that was similarly activated via the ShortFlex market. This was intended to allow Vattenfall Eldistribution to ensure that the flexibility is required would be available.

The first sthlmflex winter is an important step towards the development of the flexibility market in the Stockholm region and of markets across Europe. The project demonstrates that flexibility can compete across regions, how TSOs and DSOs can interact to resolve network congestion and how flexibility can be purchased across timeframes. The significant volumes purchased via NODES marketplace further demonstrate the potential that flexibility markets have in resolving network congestion. The work undertaken by the Sthlmflex project in enabling the market to operate this winter has further brought value across a range of other areas.

“Temporary subscription”/”tillfälligt abonnemang”: Svk offers annual subscriptions to transmission capacity to network users. The annual subscription level can be increased during the course of the year through temporary weekly increases that may or may not be granted.