Bankability of renewable energy projects in Southeast Europe is changing, with Week 23 illustrating why average day-ahead prices are no longer sufficient. The region saw higher electricity demand alongside weaker variable renewable output. Thermal generation increased, net imports rose, and prices diverged across markets. Under a simple average-price financing assumption, key risks would be missed.
Week 23 demand, generation mix and price divergence
Variable renewable output fell 8.9% week on week, including wind down 15.5% and solar down 5.1%. Regional electricity demand rose 8.2% to 15.15 TWh. Thermal generation increased by 24.5%, while net imports rose 9.1%. Prices moved differently across the region, with Bulgaria and Italy rising while Serbia, Hungary, Croatia and Romania softened.
The same market conditions can affect revenue outcomes depending on generation profiles and settlement mechanics. Solar output can coincide with low midday prices even when weekly averages remain elevated. Wind output may be strong over the year but still face high imbalance costs during volatile weeks. For merchant exposure, value can decline if generation is poorly matched to high-price hours.
Revenue modelling requirements for bankable RES projects
Bankable RES projects increasingly require layered revenue stacks rather than reliance on day-ahead income alone. Developers are expected to account for intraday optimisation and participation in balancing markets. Additional components include ancillary services and corporate power purchase agreements. The approach can also extend to guarantees of origin, battery co-location and curtailment management.
The financing focus in Greece, Romania, Bulgaria, Croatia, Serbia and Hungary reflects growing renewable pipelines and more visible grid constraints. Lenders are expected to assess not only how much energy a project produces, but also when it produces and where it is connected. The allocation of imbalance risk and curtailment is also part of the evaluation. These factors shape how revenue streams respond under week-to-week market swings.
PPA structures and battery co-location for revenue resilience
Corporate PPAs can support bankability when structured around specific risk transfers. Fixed-price PPAs reduce merchant exposure but may shift shape and balancing risk to the generator. Indexed PPAs can preserve market upside while leaving offtakers exposed to volatility. Hybrid PPAs that combine storage, guarantees of origin and delivery-shape clauses may become more common.
Batteries are increasingly used as part of the bankability toolkit, including for shifting output and reducing imbalance costs. They can capture evening spreads and improve firmness in project operations. For solar assets, battery energy storage systems can help protect against price cannibalisation. For wind assets, batteries can smooth forecast deviations and support balancing strategies.
Implications for future project design
Week 23 indicates that SEE renewables are operating in a market environment shaped by volatility, flexibility needs and grid access rather than a simple growth pattern. In this setting, returns depend on how projects are designed for changing conditions across markets. The next bankable renewable projects are expected to be those built with this complexity in mind from the start.