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 model is being demonstrated through the OPENTUNITY programme under operating conditions.
Transmission operator IPTO and distribution operator HEDNO have tested coordinated flexibility procurement through the NODES marketplace. September results are reported as a step beyond conventional demand response. 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 setup raises a commercial question about priority over the same flexible megawatt. A factory reducing electricity consumption by 2 MW could support IPTO balancing for the wider Greek system. If that factory is behind a distribution substation experiencing congestion, the same reduction may be valuable to HEDNO at the same time.
Without coordination, the two operators could request conflicting actions or unintentionally 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 has been developed between HEDNO, IPTO and NODES to assess how activations affect both networks before flexibility is dispatched. The pilot is described as an emerging example of a common flexibility market in Europe. In this model, transmission balancing requirements and distribution congestion needs are managed through a coordinated framework.
Locational value and rules for shared access
The business implications extend beyond system operation. Under a functioning flexibility market, industrial electricity users’ ability to increase or decrease consumption at a specific time and location becomes a separately tradeable service. The location of the asset matters for how that service is valued.
Two factories capable of reducing consumption by identical amounts may have different economic values depending on network conditions. One factory behind a heavily loaded substation may differ from another connected to an unconstrained part of the network. Electricity flexibility therefore begins to acquire a locational price.
The source describes potential opportunities for aggregators building portfolios based not only on total flexible megawatts but also on where individual assets are connected. Industrial refrigeration, water heating, HVAC, pumping, distributed generation, EV charging and other controllable assets could be aggregated and offered into local markets.
The Greek pilot includes portfolios of residential loads and distributed energy resources, showing how relatively small assets can be combined into a usable flexibility product. For HEDNO, the potential attraction is linked to distribution constraints that occur during limited hours each year. Paying customers to temporarily alter consumption may be cheaper than replacing transformers, cables or other network infrastructure.
In that context, flexibility can act as an alternative to part of traditional grid CAPEX. The economics are described as relevant as electrification, distributed solar, EV charging and new large loads place uneven pressure on distribution networks. A key challenge remains preventing the same resource from being sold twice.
An aggregator cannot promise a factory’s 2-MW reduction to IPTO and separately guarantee the same 2 MW to HEDNO if both operators require it simultaneously. A commercial market therefore needs clear rules covering availability, dispatch priority, baseline measurement, activation, verification and settlement. The coordination rules are presented as potentially as important as the underlying technology.
Distribution operators as buyers of short-duration services
The model also points to changes in the role of distribution operators. 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 by building physical infrastructure, an operator can potentially procure temporary changes in customer behaviour. This creates a market where aggregators, energy-service companies and software platforms operate alongside traditional equipment suppliers. It can also result in customers having several electricity relationships at once.
A company may have one supplier providing electricity while an aggregator optimises its load. In parallel, IPTO may value that flexibility for system balancing and HEDNO may value it for a local network constraint. Managing overlapping commercial relationships is identified as the next challenge.
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. As distributed resources multiply, the electricity market may increasingly ask where flexible megawatts are located and which grid operator has the highest-value use at any moment.