Greece is testing an electricity-market structure in which transmission and distribution system operators can procure services from the same pool of flexible consumers and distributed assets. The approach could create a second revenue layer for factories, commercial buildings and other controllable electricity users. The testing focuses on how flexibility value can be accessed across both grid levels.
The model is being demonstrated through the OPENTUNITY programme. Transmission operator IPTO and distribution operator HEDNO have tested coordinated flexibility procurement through the NODES marketplace under operating conditions. The tests produced September results that are reported as a step beyond conventional demand response.
Coordinating flexibility value for national balancing and local congestion
Instead of flexibility being sold to a single electricity-market buyer, resources connected to the distribution system can potentially have value simultaneously to both national and local networks. This raises a commercial question about priority when the same flexible megawatt is requested by both levels. The issue is framed around how actions at one network level could affect the other.
A factory reducing electricity consumption by 2 MW could support IPTO balancing for the wider Greek system. If that factory is located behind a distribution substation experiencing congestion, the same reduction may also be valuable to HEDNO at the same time. Without coordination, the two operators could request conflicting actions or shift congestion from one network level to another.
OPENTUNITY is testing mechanisms designed to prevent that outcome. The Greek pilot provides both operators access to flexibility connected at distribution level while NODES coordinates procurement. A dedicated coordination mechanism between HEDNO, IPTO and NODES assesses how activations affect both networks before flexibility is dispatched .
Locational value and aggregation of controllable demand
The pilot is described as an emerging example of a common flexibility market in Europe. It manages transmission balancing requirements alongside distribution congestion needs through a coordinated framework . The business implications extend beyond system operation, affecting how controllable consumption can be treated as a tradable service.
Industrial electricity users traditionally manage power primarily as an input cost. Under a functioning flexibility market, their ability to increase or decrease consumption at a specific time and location becomes separately tradeable. Location matters because two factories with identical reduction capability can have different economic value depending on whether they are behind a heavily loaded substation or connected to an unconstrained part of the network.
This locational aspect can support aggregator portfolios built around where assets are connected rather than only total flexible megawatts. Controllable loads and assets listed include industrial refrigeration, water heating, HVAC, pumping, distributed generation, EV charging and other controllable electricity uses. The pilot also includes portfolios of residential loads and distributed energy resources, showing how smaller assets can be combined into a usable flexibility product.
Distribution constraints as an alternative to grid investment
For HEDNO, the potential attraction is linked to how often distribution constraints occur during the year. If constraints arise only during a limited number of hours each year, paying customers for temporary consumption changes may be cheaper than replacing transformers, cables or other network infrastructure. In that framing, flexibility becomes an alternative to part of traditional grid CAPEX.
The relevance is tied to uneven pressure on distribution networks from electrification, distributed solar, EV charging and new large loads . At the same time, preventing double-selling of the same resource is identified as a key challenge for market design. An aggregator cannot promise the same 2 MW reduction separately to IPTO and HEDNO if both operators require it simultaneously.
A commercial market therefore needs clear rules covering availability, dispatch priority, baseline measurement, activation, verification and settlement . Coordination rules are presented as important alongside underlying technology for managing overlapping requests across grid levels.
Changing roles for DSOs under local flexibility markets
The model also points to changes in how distribution operators participate in power markets. Historically, DSOs primarily planned, maintained and reinforced networks. A local flexibility market turns them into buyers of short-duration electricity services.
Instead of addressing every constraint through physical infrastructure build-out, a distribution operator can potentially procure temporary changes in customer behaviour . This creates a market environment where aggregators, energy-service companies and software platforms operate alongside traditional equipment suppliers.
The structure can also involve customers holding multiple electricity relationships at once. One company may have an electricity supplier providing power while an aggregator optimises load; IPTO values flexibility for system balancing; and HEDNO values it for local network constraints . Managing these overlapping commercial relationships is described as a further challenge within such arrangements.
Status of Greece’s pilot and next steps for coordinated procurement
Greece’s pilot remains a demonstration rather than a mature nationwide flexibility market. However, September results indicate that the technical architecture for coordinated TSO-DSO procurement can work under operating conditions . The broader market opportunity is described in terms of how distributed resources multiply across networks.
As distributed resources increase, the electricity market may shift from focusing only on how many flexible megawatts are available toward questions about where flexibility is located and which grid operator has highest-value use at a given moment . This framing links procurement needs to both network location and operational requirements across transmission and distribution levels.
