The 21st International Conference on the European Energy Market (EEM26) brought STREAM research to Trondheim from 22 to 25 June, with two papers presented in different sessions.
Matej Pečjak from the Laboratory of Energy Policy (University of Ljubljana) presented “Simulation-Based Assessment of Flexibility in Low-Voltage Distribution Networks.” As solar panels, heat pumps and electric vehicles connect to low-voltage grids in growing numbers, they strain infrastructure that was not designed for it.
The paper asks whether demand-side flexibility can ease that strain and reduce the need for costly upgrades. Using a simulation of a real network, it compares everyday operation, grid reinforcement, and a flexibility approach based on smarter EV charging, heat pump load shifting and solar curtailment. Both reinforcement and flexibility improve conditions markedly and while reinforcement is a one-off investment, flexibility offers a lower-cost, complementary option that makes better use of existing infrastructure. The paper was co-authored by Matej Pečjak, Janez Gregor Golja, Jan Jeriha, Jernej Zupančič and Tamara Smolej Polovič.
A second paper, presented by Tadej Mavsar from ELES in the session on forecasting of market variables, examined “Analysis and forecast of congestion revenues from cross-zonal transmission capacity allocation in the Republic of Slovenia.” When the grid between bidding zones is congested, electricity prices diverge and transmission system operators collect congestion revenues, a meaningful but volatile source of financing for Slovenia’s TSO.
The paper splits total revenue into three components and links each to observed price spreads and allocated capacity, bringing in electricity futures as forward-looking indicators. Tested on 2024 and 2025, the forecasts align closely with realised revenues, with accuracy improving as each year unfolds. It is a joint contribution from ELES and the Institute for Innovation and Development of the University of Ljubljana.
