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 OPENTUNITY, transmission operator IPTO and distribution operator HEDNO have tested coordinated flexibility procurement through the NODES marketplace under operating conditions. The September results are presented 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 national and local networks.
Coordination challenge for shared flexible megawatts
The structure raises a commercial question about priority over the same flexible megawatt. A factory reducing electricity consumption by 2 MW could support IPTO balancing of the wider Greek system. If that factory is behind a distribution substation experiencing congestion, the same reduction may also be valuable to HEDNO at the same time.
The test scenario notes that, without coordination, the two operators could request conflicting actions or shift congestion from one network level to another unintentionally. OPENTUNITY is testing mechanisms designed to prevent that outcome. A dedicated coordination mechanism between HEDNO, IPTO and NODES is intended to assess how activations affect both networks before flexibility is dispatched.
The Greek pilot is described as an emerging example of a common flexibility market. In this framework, transmission balancing requirements and distribution congestion needs are managed through coordinated procurement. The demonstration is positioned as proof that the technical architecture for coordinated TSO-DSO procurement can work under operating conditions.
Locational value and rules for market access
The business implications extend beyond system operation, affecting how industrial electricity users treat power. Under a functioning flexibility market, the ability to increase or decrease consumption at a specific time and location becomes a separately tradeable service. The source material states that location matters because two factories with identical reduction capability may have different economic values depending on substation loading and network constraints.
Electricity flexibility is therefore described as acquiring a locational price. The text also links this to opportunities for aggregators building portfolios based on where assets are connected rather than only total flexible megawatts. It lists controllable resources that could be aggregated and offered into local markets, including industrial refrigeration, water heating, HVAC, pumping, distributed generation and EV charging.
The pilot includes portfolios of residential loads and distributed energy resources to show how relatively small assets can be combined into a usable flexibility product. For HEDNO, the stated attraction is that when distribution constraints occur only during limited hours each year, paying customers to temporarily alter consumption may be cheaper than replacing transformers, cables or other network infrastructure. Flexibility is described as an alternative to part of traditional grid CAPEX.
A key challenge identified is preventing the same resource from being sold twice. The text states that 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. It adds that clear rules are needed for availability, dispatch priority, baseline measurement, activation, verification and settlement.
Changing roles for distribution operators and overlapping relationships
The model also points to changes in the role of distribution operators within electricity markets. Historically, DSOs primarily planned, maintained and reinforced networks. A local flexibility market is described as turning them into buyers of short-duration electricity services.
The approach is framed around procuring temporary changes in customer behaviour rather than building physical infrastructure for every constraint. This would create a market in which aggregators, energy-service companies and software platforms operate alongside traditional equipment suppliers. It could also result in customers having several electricity relationships at once.
The source describes scenarios in which a company has one supplier providing electricity while an aggregator optimises its load, IPTO values flexibility for system balancing and HEDNO values it for a local network constraint. Managing overlapping commercial relationships is identified as the next challenge after coordination mechanisms.
Greece’s pilot remains a demonstration rather than a mature nationwide flexibility market. However, the September results are cited as showing that coordinated TSO-DSO procurement can function under operating conditions. As distributed resources multiply, the text says the market may increasingly ask where flexible megawatts are located, who needs them and which grid operator has the highest-value use at that moment.