Flexibility has become a key attribute for power assets in Europe’s electricity system as grids rely more on fast response to manage variable generation. The ability to ramp quickly, absorb surplus output, stabilise frequency and respond to sudden imbalances is increasingly important alongside installed capacity. While flexibility is scarce, it is not priced in a way that reflects its system role. The mismatch is visible in southeast Europe.
Across the Balkans and the eastern Mediterranean, power systems provide support to the wider European grid through multiple physical mechanisms. Hydropower reservoirs can absorb renewable oversupply, while thermal plants provide inertia and backup during scarcity. Transmission corridors also move electricity flows linked to weather patterns occurring hundreds of kilometres away. In physical terms, southeast Europe is embedded in Europe’s balancing logic.
Economically, the region captures limited value from that role. Market arrangements reward energy delivery more than system services even as grids increasingly depend on those services to operate reliably. This structure reflects earlier market designs layered onto a system with higher shares of wind and solar. As a result, flexibility is used without being remunerated proportionately.
From implicit flexibility to explicit balancing needs
In earlier operating conditions, flexibility was largely an outcome of baseload generation. Coal, gas and nuclear plants provided ramping and stability as by-products of their routine operation. Demand patterns were more predictable and balancing requirements were smaller. Markets therefore focused on energy volumes rather than system services.
With today’s generation mix, flexibility is required more explicitly. Wind and solar dominate output during certain hours and can fall away entirely during others, while demand remains relatively inflexible. The gap between supply and demand must be covered by assets capable of rapid response. Southeast Europe holds several resources that can meet these requirements.
Hydropower is a central example of fast-responding capability in the region. Albania, Montenegro, Bosnia and Herzegovina, Croatia and parts of Serbia operate hydro systems able to respond within minutes. These reservoirs function as storage systems, reserve providers and frequency stabilisers. With large-scale storage still limited across the continent, Balkan hydro is described as one of Europe’s valuable system resources.
Thermal and gas plants used for stability
Coal plants continue to provide flexibility through their thermal characteristics in several southeast European systems. Their thermal mass contributes inertia that dampens frequency swings linked to sudden renewable changes. They can operate at partial load, respond to dispatch instructions and support local systems during stress. In many countries, coal remains part of the last line of defence during extreme conditions.
Gas can add additional responsiveness where infrastructure exists, but it faces constraints in the region. Higher fuel costs, infrastructure limitations and lower utilisation rates mean gas often functions as emergency backup rather than a commercially optimised balancing resource. The flexibility available in southeast Europe is frequently tied to assets built decades earlier for different system needs. Those assets are repurposed to support a continental grid that did not exist when they were financed.
Despite this physical contribution, financial rewards are concentrated elsewhere in the market design. Day-ahead markets dominate price formation across Europe, including coupled and semi-coupled markets in southeast Europe. They clear energy volumes based on marginal costs rather than paying for response speed, reserve availability or system stability. Flexibility is then used after prices are set through balancing actions that may cover costs but not opportunity value.
Volatility exposure without control over price drivers
The pricing structure contributes to an undervaluation of flexible assets across the region. Hydro plants may be dispatched intensively during high-price periods but earn little during oversupply hours when prices fall sharply. Coal units can be pushed into operating patterns that are uneconomic while still carrying reliability expectations. Gas plants may struggle to recover fixed costs when utilisation is sporadic and price spikes are difficult to predict.
The pattern also links to how volatility moves across interconnected markets. Renewable oversupply in the EU core tends to push prices down across connected systems through transmission effects. Southeast European systems absorb this oversupply physically via imports or by backing down domestic generation. When conditions reverse, price spikes driven by gas scarcity or low renewable output elsewhere can reach the region through the same market linkages.
This results in one-way exposure for southeast Europe to both low-price and high-price periods without controlling underlying drivers. The region does not determine when generation such as German solar or North Sea wind changes output levels. It also does not influence French nuclear availability or Italian demand peaks that affect European prices. Instead, those outcomes are reflected in domestic market conditions.
Hydro dispatch constraints and drought risk
Hydropower illustrates how system value can differ from market outcomes under real-world constraints. In theory, hydro should benefit from volatility by earning higher prices during scarcity while conserving water during oversupply periods. In practice, political pressure, regulatory constraints and market imperfections limit optimisation across dispatch decisions.
Governments intervene to maintain affordability for consumers, which can affect how hydro is scheduled in stressed periods. Water management obligations constrain dispatch choices even when price signals would otherwise support different operation patterns. Cross-border price signals can also be diluted by congestion on interconnectors into neighbouring markets. The outcome described is intensive use of hydro flexibility without matching financial returns.
Climate change adds additional risk related to water availability across the Balkans. Drought risk is rising as years with abundant rainfall alternate with severe shortages. During EU-driven stress events when hydro is overused, reservoirs can enter dry seasons depleted, reducing both output and system resilience. Prices respond to immediate scarcity rather than cumulative depletion of strategic water resources.
Carbon policy impacts coal economics
Coal faces challenges tied to carbon pricing and environmental regulation even where its system role remains relevant. As carbon prices rise and environmental rules tighten, coal plants lose economic viability while continuing to be valued for security reasons. They are asked to remain available even as they may be discouraged from operating for economic or environmental grounds.
Compensation mechanisms described for maintaining availability are often ad hoc and politically contentious, with levels insufficient for long-term investment support. This creates a situation where the power system relies on assets it is simultaneously trying to reduce or phase out operationally under policy goals.
Gas marginal pricing and shallow balancing markets
Gas transmits EU-level volatility into southeast European markets through price-setting dynamics during scarcity events across much of Europe. Gas sets the marginal price during these events that influence wholesale outcomes throughout interconnected areas. Southeast European gas consumers face these prices without access described as comparable liquidity, hedging depth or mitigating infrastructure found in western markets.
The same gas-driven price spikes that encourage flexible investment in the EU core are described as cost shocks for peripheral systems like those in southeast Europe. Market design further amplifies these effects through differences between intraday and balancing arrangements across regions.
Intraday and balancing markets in southeast Europe remain shallow compared with western counterparts according to the description provided here. Access to cross-border balancing is limited and ancillary services markets are fragmented or underdeveloped in parts of the region. Flexibility is therefore procured administratively rather than competitively in many cases, which suppresses price discovery and investment incentives.
Investment signals affected by underpayment
The imbalance affects investment behaviour beyond day-to-day dispatch decisions. When flexibility is underpaid, investment can stall as financing becomes harder for new projects intended to provide system services. Maintenance may also be deferred when revenue streams do not support long-term asset upkeep.
The power system becomes more dependent on ageing assets operating under stress as new capacity struggles to reach financial close under these conditions described here. Political intervention increases as governments attempt to shield consumers from volatility through measures that can distort market signals further.
Integration focused on energy trading rather than services
From the EU core perspective, the imbalance may be less visible because wholesale markets appear to function within coupled trading arrangements described here. Prices clear across interconnected systems and renewable targets can be met while cross-border flows smooth variability at an operational level. Costs are dispersed across peripheral systems through reduced margins and deferred investment rather than concentrated where flexibility is physically provided.
Southeast Europe’s situation is described as a structural mismatch despite progress on market integration tools such as price coupling and flow-based allocation linking markets more tightly than before. The issue highlighted here is that integration has centred on energy trading without adequately integrating system services needed for stability provision.
A shift toward recognising flexibility as a tradable commodity would require separate markets for inertia, ramping capability and storage with their own pricing signals described here as necessary components of true integration. Opening balancing markets across borders would also require valuing those services explicitly rather than treating them only as side effects of energy production.
Limits on absorbing stress within local systems
Southeast Europe remains described as supplying physical stability while receiving limited proportional return under existing arrangements until reforms occur unevenly or slowly across regions. Systems can absorb stress only up to point before resilience erodes under repeated strain conditions described here through hydro depletion risks and coal economics pressures.
Hydro reservoirs cannot be overdrawn indefinitely under water constraints tied to drought risk dynamics described earlier here for the Balkans region. Coal plants cannot operate indefinitely under hostile economics if policy frameworks continue tightening while reliability expectations remain unchanged without adequate compensation mechanisms described here.
The consequences described are not expected to remain confined regionally once limits are reached across local systems supporting broader grid stability needs throughout Europe’s interconnected network structure.
Elevated by clarion.energy