February 17, 2026
Soomin Woo, Leo Strobel, Yuhao Yuan, Marco Pruckner, Timothy E. Lipman, Exploring bidirectional charging strategies for an electric vehicle population, Applied Energy, Volume 397, 2025, 126361, ISSN 0306-2619, https://doi.org/10.1016/j.apenergy.2025.126361.
A November 2025 paper in Applied Energy by researchers at UC Berkeley’s Transportation Sustainability Research Center and collaborating institutions tackles a question V2G stakeholders often talk around but rarely quantify with real operating data: how much value can bidirectional charging actually produce, and which real-world constraints determine whether that value is realized?
The study’s starting point is a practical one. Despite years of V2G promise, it remains unclear how to design operations that balance mobility needs with grid cost signals, and whether the incremental complexity of V2G (versus smart charging alone) is justified. The authors respond with a framework that compares multiple “service designs” for V2G and V1G, explicitly layering in constraints that resemble what customers and programs are likely to require (like departure SOC guarantees and limits on where bidirectional hardware is available).
What the researchers set out to understand
The paper’s objectives are explicit: propose “realistic” V2G strategies, evaluate them using actual EV charging data, and identify the parameters that most affect benefits (revenues and emissions).
This is not an abstract modeling exercise built on assumed plug-in schedules. The authors emphasize a gap in the literature: many V2G valuation studies rely on stylized driving patterns or incomplete charging records, and often do not interrogate key design variables like equipment availability by location, driver SOC guarantees, charging/discharging efficiencies, aggregator fees, and degradation compensation.
Method: real EV data + optimization across six operating strategies
The analysis is built on telematics data from 309 BMW EVs and PHEVs in the San Francisco Bay Area, using a dataset with a complete charging history over a defined window (6/11/2017/–12/01/2017). Vehicle battery capacities in the dataset range roughly 12–40 kWh, and rated charging power is 3.6–7.4 kW, reflecting typical Level 2 AC limits for that vehicle population.
To test value under future-like conditions, the study pairs real mobility/charging behavior with synthetic hourly price signals from Berkeley Lab’s CalFlexHub project, designed to be revenue-neutral overall but much more time-differentiated, reflecting a grid with large swings (e.g., low-cost renewable hours and high-cost peak hours). Emissions impacts are estimated using WattTime’s marginal operating emissions rate (MOER) for CAISO.
The core engine is an optimization model that minimizes net charging costs (allowing negative costs, i.e., revenue). Critically, the paper compares six operational strategies that represent different program “rules” and infrastructure realities:
- Full V2G (most flexible, bidirectional wherever the vehicle is plugged in)
- V1G (smart charging only, no discharge)
- Net Positive V2G (departure SOC must be at least arrival SOC for each session)
- Fixed Location V2G (departure SOC must be at least the observed SOC from real data for that session)
- Home V2G (bidirectional at home, V1G elsewhere)
- Public V2G (bidirectional in public/work, V1G at home)
This structure is one of the paper’s key contributions: it turns “V2G” into a set of distinct service designs that can be compared on outcomes.
Key results: V2G value is large in the “best case,” but location and program rules matter
Under idealized assumptions (perfect efficiencies, no degradation compensation, no haircut to discharge revenue), the results are striking: the most aggressive strategy produces ~$2,397 per vehicle per year under one of the dynamic price signals (Two-peak). Full V2G also shows a “synergy” with emissions reduction in this California context, with emissions falling substantially relative to baseline charging. But the more important story for market design is how much value remains once “realistic” constraints are introduced.
V1G still helps, but it’s not the same league. Smart charging reduces energy cost significantly relative to baseline, but the modeled annual value is modest compared to bidirectional strategies. Driver-friendly guarantees don’t kill value. The Net Positive V2G strategy (no session ends below where it started) delivers revenues close to Full V2G. Likewise, the Fixed Location V2G constraint, designed to preserve the same departure SOC experience as observed in the real data, still produces very high modeled revenues (on the order of ~$2,000/vehicle-year in the best price-signal case). This is a major result because it suggests you can impose intuitive “consumer protection” constraints without necessarily destroying the economics.
Home is where the money is (in this dataset and price shape). Home V2G far outperforms Public V2G. In the Two-peak case, Home V2G is modeled at ~$1,954/vehicle-year, while Public V2G is only ~$515/vehicle-year. The reason is straightforward: in California, the highest prices occur in evening hours when vehicles are typically home, and dwell time at home is long, so the export opportunity aligns with both price and availability.
The paper also shows how V2G fundamentally reshapes the daily load profile. Under baseline behavior, EVs simply add modest, mostly evening charging load to the grid. But optimized V2G strategies concentrate charging into low-price, solar-heavy midday hours and introduce discharging during high-price evening peaks. The result is a much larger swing in net load over the course of the day, strong positive load when renewable energy is abundant, and negative load (grid support) when demand is highest. In other words, EVs shift from being passive consumers of electricity to active balancing assets. That wider swing is exactly what utilities care about in solar-heavy systems: filling midday valleys, shaving evening peaks, reducing curtailment, and lowering capacity needs.
What Makes or Breaks V2G Economics: Efficiency, Fees, Degradation, & Technology Scale
Where the study becomes especially useful for the V2G industry is in its sensitivity analysis. Rather than treating profitability as fixed, the authors identify a short list of variables that can materially erode, or expand, customer value.
Three “value killers” stand out.
Charging efficiency matters more than many people realize. When energy can move in and out of the battery with minimal losses, V2G works much better. High efficiency means more usable energy for selling back to the grid and less wasted power. But if efficiency is low, those losses eat into the margins quickly, reducing both revenue and emissions benefits.
Fees and revenue-sharing rules also make a big difference. In the study’s most optimistic case, cutting discharge payments by 30%, which could represent aggregator fees or market rules, reduces V2G earnings by more than half. That’s a striking result. It means the business case for customers can disappear quickly if too much of the market value is taken out before it reaches the vehicle owner.
Battery wear and tear is another important factor. When the model assumes drivers are compensated for battery degradation on a per-kWh basis, discharge activity falls, and revenues decline. At higher compensation levels, profits drop sharply. The study does not dismiss battery degradation. Instead, it shows that V2G can still work, but only if pricing, efficiency, and revenue sharing are designed carefully so that enough real value flows back to the customer.
The technology trajectory strengthens this conclusion. The study compares “current” EV specifications with “future” scenarios featuring larger battery capacities and higher Level 2 charge/discharge power. The direction is clear: larger batteries and higher power ratings materially increase revenue potential and reduce unit energy cost. With more flexible energy to shift and greater power to respond to price signals, vehicles can capture more value from time-varying rates. The authors explicitly connect this to typical North American residential service constraints (e.g., 40A–48A circuits), underscoring that near-term hardware improvements can translate directly into stronger economics.
What This Means for the V2G Industry
This study moves the V2G conversation beyond theory and into practical design. Using real-world driving data and realistic operating constraints, it shows not just that V2G can create value, but what determines whether that value actually reaches customers and scales. For the industry, the implications are less about technical feasibility and more about market design, deployment strategy, and customer economics.
- Customer-friendly rules can still create real value: V2G does not require aggressive, customer-hostile dispatch. Even with guarantees like “leave with at least what you expected,” the modeled economics remain strong. That’s a critical finding for regulators and program designers.
- Rate design makes or breaks the business case: The value in this study comes from dynamic, time-varying prices, especially solar-heavy price spreads. Without meaningful price differences between midday and peak hours, arbitrage value shrinks quickly.
- Home deployment matters more than public: In this dataset, residential V2G generates far more value than public charging. Why? Vehicles are home when prices are highest. If hardware dollars are limited, home installations may deliver more value per vehicle.
- Customer economics are fragile: Aggregator fees, efficiency losses, and battery degradation assumptions can cut profits dramatically. If too much value leaks out before reaching the driver, participation will stall. Program design and revenue sharing matter.
The encouraging takeaway is that V2G economics improve materially as technology advances. Larger batteries, higher charging power, better efficiencies, and maturing standards all expand the value envelope. As bidirectional capability becomes more common and markets evolve to reward flexibility, the gap between “pilot potential” and scalable opportunity can narrow quickly. The fundamentals are strengthening, and that’s good news for the sector.
