Bulgaria’s electricity system is under mounting pressure. Renewables now account for 54.5% of installed generation capacity, solar PV alone reached 6,505 MW in 2026, and the system is already producing sustained periods of negative wholesale prices — clear evidence that the flexibility challenge is no longer a future concern but a present operational reality. On a typical spring day, solar dominates midday generation while evening prices spike to 250 EUR/MWh as output collapses. Managing this daily cycle is the defining challenge of Bulgaria’s energy transition, and digital technologies are the primary lever for doing so. Digitalisation offers a critical lever – from smart grids and automated control systems to flexibility aggregation platforms and demand-response solutions.
On 27 May as part of RE-Source Southeast conference 2026, Net-Zero Lab organised a focused expert discussion, “Electricity System Flexibility in Bulgaria: Unlocking the Digital Opportunity” to bridge the research perspective with on-the-ground experience of practitioners actively deploying digital solutions in Bulgaria’s energy sector.
The discussion was joined by the speakers Philip Georgiev, Managing Director and Co-founder, EnAuxo Ltd., Boyko Uzunov, Business Development Manager Energy Solutions, Telelink Infra Services, Deyan Vasilev, Sales Manager, Siemens Bulgaria, Evo Stefanov, Managing Partner, Methodia, and Mariyana Yaneva, Chief Operating Officer, International Power Supply (IPS).
Dr. Mariya Trifonova, Deputy Head of the Net-Zero Lab, moderated the discussion and presented the lab’s latest report, Scaling Up Electricity System Flexibility in Bulgaria Through Digital Solutions. The report was prepared by a team from the Technical University of Sofia, including Dr. Metodi Georgiev and Dr. Alexandra Georgieva. The discussion was sparked by six key findings highlighted in the report:
- The solar revolution has already happened. Over half of Bulgaria’s installed generation capacity is from renewable sources and in certain hours on spring days solar power contributes to up to 80 % of the generation.
- More solar panels alone do not solve the problem. The scenario analysis from the report Scaling Up Electricity System Flexibility in Bulgaria Through Digital Solutions shows that increasing solar capacity by 50% without anything else reduces the evening flexibility deficit from 160 to 118 GWh per year – only 27% improvement with twice the generation investment. The improvement curve saturates. The system needs approximately 1.5 GWh of battery storage and active demand management. Further increases in installed PV capacity, without accompanying flexibility measures, will not deliver proportionate system benefits — and will instead generate growing volumes of curtailed generation that destroy economic value without improving system balance.
- Bulgaria is operating a two-speed digitalisation system. The TSO transmission network is technically modern: 9,000 km of fibre, digitalised substations, SCADA/EMS modernisation under the RRM. The distribution layer is a different story: smart meter penetration ranges from 15% to 75% depending on the DSO, no mandated national communication standard, no private communication networks. No aggregator can offer a national flexibility product without triple integration.
- Communication infrastructure is the real bottleneck. PLC, MQTT and Modbus TCP — three different protocols independently chosen by the three DSOs, are adequate for billing but not for real-time control. Romania resolved this with one regulatory decision: mandatory DLMS/COSEM standard for all new meters. Bulgaria has not yet taken that decision. The report identifies it as the single most impactful regulatory action available.
- Cybersecurity is no longer an IT question, but an operational risk. Attacks on the energy sector increased by 80% in 2024. EU legislation is in force regardless of Bulgaria’s incomplete transposition. Operators waiting for the legislator are accumulating risk. The advice is simple: start with a risk assessment now
- The action window is 2026–2029, not the next decade. The instruments are in place: a liberalised balancing market, an energy community framework, RRF, Horizon Europe, CEF. The same conditions that enabled Germany, the Netherlands and Austria to build thousands of megawatts of virtual power plants exist today in Bulgaria. The next DSO investment cycle will either open or close the next decade.
The discussion was opened by Philip Georgiev, who highlighted the growing importance of flexibility solutions in the increasingly volatile energy landscape of Central and South-Eastern Europe. EnAuxo is currently modelling multiple flexibility business cases to provide bankable, data-driven insights for future investments. While the analysis confirms that diverse flexibility technologies can capture value across short-term, hourly, and potentially sub-hourly markets, Georgiev noted that investors must also consider diminishing returns resulting from increasing market competition and the potential narrowing of future price spreads. He emphasized that the greatest opportunity lies in integrated flexibility strategies that combine generation, storage, and smart demand-side response, enabling both industrial consumers and asset owners to remain competitive in a rapidly evolving market over the next five to seven years.
Boyko Uzunov focused on the ongoing transition toward decentralized energy infrastructure, including the emergence of new industrial and gas-related energy nodes, flexible generation and storage models, and utility-scale solutions aimed at peak shaving and cost optimization. He outlined three interconnected layers of digitalisation necessary for this transformation: field-level digital tools, intelligent energy management systems, and digital twins capable of supporting advanced system planning and operation.
Drawing on the United Kingdom’s experience with electricity market liberalisation and smart metering, including the MHHS half-hourly settlement system, Evo Stefanov discussed lessons relevant for Bulgaria’s energy transition. He stressed that innovation should be led by industry stakeholders and business associations rather than relying solely on government action. According to Stefanov, while governments can provide the necessary regulatory framework, meaningful transformation is ultimately driven by actors who understand the practical need for change.
Deyan Vasilev presented Siemens Bulgaria’s existing technological solutions for managing and monitoring decentralized energy producers and consumers, including battery storage systems connected to low- and medium-voltage grids. His presentation demonstrated that many of the technological capabilities required for enhanced system flexibility and decentralized energy management are already commercially available.
Mariyana Yaneva broadened the discussion by linking energy system flexibility and grid stability to wider geopolitical and cybersecurity considerations. She emphasized that modern electricity systems should no longer be viewed solely through the lens of physical infrastructure, but also as highly digitalized and interconnected systems increasingly exposed to geopolitical risks and cyber threats.
The full report is available here.