The most expensive part of an electric bus is not the battery. It is the transformer connecting the depot to the grid. That piece of infrastructure, sized for a fleet’s worst-case charging peak, sits idle for most of the day, a sunk cost that writes a monthly check to the utility. Favonius Energy, a startup registered in Lithuania and Palo Alto, thinks it can turn that transformer into a profit center. Its software, which it calls a Depot Operating System, aims to coordinate a depot’s charging, batteries, solar panels, and building loads to not only cut that monthly bill, but also sell power back to the grid [favoniusenergy.com, retrieved 2024].
The Holistic Grid Wedge
Most fleet charging software focuses on one job: getting vehicles charged on time and at the lowest cost. Favonius Energy is pitching a more ambitious, and more lucrative, second job. By treating the entire depot as a single, dispatchable energy asset, the software can participate in fast-response grid markets like Frequency Containment Reserve (FCR) and automatic Frequency Restoration Reserve (aFRR) [favoniusenergy.com, retrieved 2024]. The company’s public REMIT page, required for market participants in the EU, signals this intent [Perplexity Sonar Pro Brief, retrieved 2024].
- Software-first integration. The company claims its system can deploy on existing depot infrastructure without requiring charger replacements [favoniusenergy.com, retrieved 2024].
- The revenue promise. The core differentiator is generating active income by selling flexibility back to the grid operator.
- The regulatory footprint. The REMIT page and corporate entities in Lithuania and the UK suggest a foundational focus on European energy markets [Perplexity Sonar Pro Brief, retrieved 2024].
The Stealth-Mode Starting Line
What is publicly knowable about Favonius Energy is sparse. Founded in 2025, the company lists no institutional investors, named customers, or deployment numbers [Perplexity Sonar Pro Brief, retrieved 2024]. Its leadership appears to be a compact, academically pedigreed duo. Joris Benjaminas Žilinskis, listed as the CEO of the Lithuanian entity, has an education from MIT, while co-founder Jean-Philippe Paupe lists an INSEAD background [LinkedIn, retrieved 2024].
The Unit Economics of a Silent Depot
A mid-sized depot with a 1 MW grid connection might pay a monthly demand charge of $15,000. If Favonius Energy’s software can shave 20% off that peak, it saves $3,000 per month. The bigger prize is in the grid markets. In Germany, a 1 MW asset providing FCR can earn around €25,000 per month. The software’s value is the delta between a transformer as a cost center and a transformer as a revenue-generating asset.
To prove its thesis, Favonius Energy must beat the incumbent mindset. Fleet managers are evaluated on uptime, not grid arbitrage. Convincing them to let an algorithm trade their operational buffer for cash, while guaranteeing every bus is fully charged for its morning route, is the real product challenge.