Engagement Context
A German municipal utility serving 280,000 residents required a distributed energy resource management system (DERMS) capable of coordinating 340 MW of distributed solar generation, 48 MW of battery storage, and the existing grid infrastructure to reduce peak load demand on the transmission connection and improve grid resilience under N-1 fault conditions.
DERMS Architecture
The DERMS architecture was built on IEC 61968 Common Information Model for asset modelling, with OpenADR 2.0 for demand response communication to aggregated flexible loads, and IEC 61850 for protection and control communication with grid-connected storage assets. The system required integration with the existing distribution management system (DMS) to provide real-time visibility of grid topology for optimised DER dispatch decisions.
Real-time state estimation was implemented at 15-second resolution across 1,240 grid monitoring points, providing the situational awareness required for automated DER dispatch under dynamic grid conditions.
Resilience Design
The resilience design focused on the N-1 fault condition: the loss of the primary transmission connection. Under this condition, the distribution network must operate in islanded mode, with DER generation and battery storage providing all load supply. The DERMS was designed to detect the N-1 condition, initiate automatic islanding of designated grid zones, and manage DER dispatch to maintain supply continuity for critical loads.
Documented Outcomes
Peak load demand on the transmission connection was reduced by 28% in the first year of operation, exceeding the programme target of 20%. The reduction was achieved through a combination of optimised battery charging and discharge scheduling (16% contribution) and demand response activation during peak periods (12% contribution). The system successfully executed islanded operation during two N-1 events in the first year, maintaining supply continuity for all critical loads in both cases.