There are six distribution network operators (DNOs) in Britain, covering fourteen DNO geographical areas. As the system evolves, DNOs are becoming more active in the procurement of flexibility services to manage constraints and avoid or defer infrastructure spend.
Most DNO services will commit you to participate in a specific service at a specific time to overcome a locational constraint, so the decision to participate and the bidding prices in DNO tenders will be driven partly by the opportunity cost of coming out of real-time services elsewhere. In the future, we expect to see changes to the market that will allow for better stacking of DNO services with other revenue sources such as the Balancing Mechanism.
As the DNOs start to manage their networks in a more active way, they are recasting themselves as Distribution System Operators, or DSOs.