Theodor Hagström and Lars Herre, researchers from the KTH Royal Institute of Technology in Sweden, have delved into the potential of electric vehicle (EV) fleets to participate in the Nordic 15-minute mFRR Energy Activation Market (EAM). Their study, published in the journal Applied Energy, explores the business case for EV aggregation in this market, which is characterized by shorter market time units (MTUs) and gate closures.
The researchers note that the energy sector is undergoing significant changes, with decarbonization, decentralization, and the increasing intermittency of renewable energy sources driving the development of flexibility markets. Shorter MTUs and gate closures, they argue, lower the entrance barriers for demand side aggregators, who face significant uncertainty on longer time scales.
In their study, Hagström and Herre represent fleet flexibility as a virtual battery with time-varying power and energy envelopes. They formulate a risk-aware stochastic optimization that coordinates day-ahead scheduling with quarter-hour mFRR bidding. Using synthetic residential charging cohorts and observed day-ahead prices on two stylized days, they compare an independent day-ahead baseline to a co-optimized strategy under conservative availability and a CVaR-augmented objective.
The researchers found that co-optimization increases expected profit and lowers downside risk. The model buys less energy day-ahead and shifts procurement toward mFRR down while flattening the charging plan to retain eligibility for mFRR up. Profit decomposition shows that the uplift is driven by higher mFRR down revenues and reduced reliance on unwinding day-ahead positions.
Hagström and Herre discuss the operational implications for bidding and outline two extensions: rolling 45-minute re-optimization and a V2G (vehicle-to-grid) framework. They suggest that their findings could have practical applications for energy companies looking to integrate EV fleets into their operations and participate in flexibility markets.
The study, titled “Understanding Risk and Revenue in the Nordic 15-minute mFRR market: An EV Aggregation Study,” was published in the journal Applied Energy.
This article is based on research available at arXiv.