Vehicle-to-Grid

Vehicle-to-Grid (V2G) allows an electric vehicle (EV) battery to discharge electricity back into the grid via a bidirectional charger, turning the EV into a mobile distributed energy resource. V2G is a subset of the broader Vehicle-to-X (V2X) concept — bidirectional power transfer from an EV to any external system.

V2X taxonomy

(Source - Power Circle V2X Synthesis 2024)

V2H is widely viewed as a gateway product for V2G adoption — consumers experience direct, immediate financial benefit (self-supply) before engaging with the more complex grid services market. (Source - KTH Thesis V2G Sweden 2024)

How V2G works

Hardware: a bidirectional charger (wallbox or EVSE) capable of both charging (G2V, grid-to-vehicle) and discharging (V2G). An inmatningsabonnemang (grid injection subscription) is required at the connection point to export electricity to the grid.

AC vs DC:

• AC bidirectional: inversion (AC↔DC) happens inside the vehicle’s on-board charger (OBC); wallbox is cheaper; but AC V2G communication protocols are less mature — the AC standard does not include state-of-charge data in the standard communication layer
• DC bidirectional: inversion in the external charger; wallbox is more expensive; better protocol maturity for communication between charger and grid systems

The AC/DC choice is a business-model fork, not only a protocol one. Volkswagen’s Swedish deployment (the Stenberg/Hudiksvall and Vattenfall/Energy Bank pilots) runs DC with the inverter in the charging box — simpler and stationary, reusing the same pattern as a rooftop-solar inverter, and described by practitioners as the more accessible near-term route. Markets that have instead chosen AC-in-vehicle gain a theoretically portable resource (the car could earn wherever it’s parked) but are considerably further from working business models in practice than the stationary DC/wallbox approach. A related strategic fork sits with OEMs and EVSE makers: a “closed” charger model (the OEM controls home charging and locks the customer to its own box) versus an “open” model (the customer mixes charger brands and integrates across products) — framed by Varberg Energi (with Ferroamp likewise pointing to the OEMs as the key) as the choice that will determine how V2G actually develops. (Source - Så Kan V2G Gå Från Projektform Till Marknaden (2025))

Communication standards:

• ISO 15118-20 — bidirectional charging protocol for vehicle–charger communication; the enabling standard for V2G at the charging interface; operates during the Usage phase (EV connection, authentication, negotiation of charging/discharging parameters)
• OCPP 2.1 (Open Charge Point Protocol) — charger-to-backend communication protocol; enables aggregation platforms to control and monitor charging sessions; also used at the Installation/Configuration phase for remote EVSE setup before the service goes live
• OpenADR / IEEE 2030.5 — used during the Usage phase to carry demand response signals and dynamic pricing from Aggregator platforms to EVSE/DER systems
• IEC 61850 — grid infrastructure standard used in backstage coordination between Aggregator platforms and DSO/TSO control systems

(Source - Power Circle V2X Synthesis 2024, Source - Malakhatka et al V2G Service Blueprint Sweden (2026))

EU grid-connection requirements and certification (from mid-2026)

Beyond the communication/aggregation standards above, V2G EVs and V2G EVSE are, for the first time, being brought within the EU’s generator connection requirements framework. The European Commission’s July 2026 draft revision of RfG defines V2G EV and V2G EVSE as a distinct category of electricity storage module (ESM) and sets out a dedicated certification framework (Annex III): the EV and EVSE are certified individually against grid-code compliance, using test methods from EN 50549-10:2022, by certifiers accredited under EN ISO/IEC 17065 — with AC V2G EVs normally certified via the Whole Vehicle Type Approval (WVTA) route once that becomes available. Once the Regulation enters into force, requirements apply after 3 years for new vehicle types and 4 years for all new vehicles placed on the market. This is a separate, EU-regulatory-compliance layer that sits alongside (not instead of) the communication/interoperability standards above — see Generator Connection Requirements › NC RfG 2.0 — the Commission’s draft revised RfG (July 2026) and Source - EU Commission Draft Revised RfG and Annexes (2026) for detail.

Grid services V2G can provide

RISE (Research Institutes of Sweden) frames V2G’s value beyond individual market products: a diverse EV fleet is a naturally distributed frequency-regulation resource (more reliable than depending on a few large plants), bidirectional EVs can defer T&D capacity expansion by supplying peak power instead, and in a conflict or major blackout scenario a fleet of bidirectional EVs is “extremely valuable” flexible storage for societal resilience — a value beyond ordinary market participation. Realizing any of this depends on an intermediary ecosystem (aggregators, software, contracts), since private vehicle owners are unlikely to contract directly with Svenska kraftnät. (Source - RISE V2G Overview 2026)

Swedish market potential

(Source - Power Circle V2X Synthesis 2024, Source - FlexAbility Delrapport 1 (2025))

The 5,000 MW figure from FlexAbility assumes 20% of the EV fleet is V2G-compatible by 2030 and available for dispatch. The actual realizable share in 2030 is much lower due to the regulatory, technical, and commercial barriers described below. (Source - FlexAbility Delrapport 1 (2025))

BEV fleet trajectory (Power Circle 2026): the installed base that underpins these potentials is growing fast but from a stalled position. Power Circle’s June 2026 BEV forecast puts ~460,000 BEVs in traffic in 2026, reaching 1 million during 2029 and 2 million during 2033 in the base scenario — Sweden having stalled at 35–40% of new-car sales since 2022 (now worst in the Nordics). Two implications for V2G: the dispatchable fleet scales materially only from the late 2020s, and the apartment-charging gap (~half of Swedes lack guaranteed home charging) caps the residential share that can realistically offer V2G without structural charging-infrastructure measures. (Source - Power Circle Elbilsprognos 2026-2035 (2026))

Actual 2025 consumption anchor: Energimyndigheten statistics put Sweden’s passenger-EV fleet at ~500,000 vehicles (~10% of the national vehicle fleet) as of late 2025 — consistent with the Power Circle trajectory above — consuming 2,528 GWh of electricity in 2025 (+485 GWh year-on-year). Heavy electric trucks and buses, while a much smaller absolute volume (254 GWh combined), grew far faster in percentage terms (+109%/+66%), pointing to accelerating heavy-vehicle electrification from a low base. All Swedish road-transport EV charging combined (2,910 GWh) remained under 9% of Sweden’s 2025 net electricity export alone — Energimyndigheten’s framing is that even rapid fleet growth poses no near-term national supply-adequacy risk (elbrist), a claim about aggregate production/export headroom, not about local distribution grid capacity, which remains a separate constraint (see Grid Capacity Utilization). (Source - Nya Siffror - Så Lite El Använder Sveriges Elbilar (2026))

Nordic energy system context

Nagel et al. (2024) modeled V2G in Norway and Denmark using the Balmorel energy system model for a 2040 system. The central finding — directly relevant to Sweden’s four bidding areas:

V2G value depends fundamentally on the flexibility mix of the system:

Additional results:

• System operational cost reduction: ~3%
• CO₂ emissions intensity across the full modeled Balmorel system: −33% (6.85 → 4.59 gCO₂/kWh produced), from reduced curtailment and peak fossil generation — the Nordics alone are already ~zero-emission in the 2040 base case, so this reduction is mostly realized in the wider modeled system
• V2G supplies up to 55% of system load in DK2 at peak hours under large-scale adoption (system-wide average: 11%)
• Curtailment reduction: Denmark 30% (Norway: none observed, already very low)
• Airport V2G revenues: negligible vs home V2G (e.g., DK1: €1.8M airport vs €290.9M home)

Swedish bidding area implication (wiki inference from regional characteristics):

• SE1–SE2 (north, hydro-dominated): likely Norway-like — V2G adds less value; risk of price increases at high adoption
• SE3–SE4 (central/south, VRE-growing + import dependency): more Denmark-like — V2G more valuable; higher adoption economics

Prisoner’s dilemma at scale: large-scale V2G adoption flattens the price duration curve, eliminating the low-price charging valleys that make V2G profitable. Individual incentive to participate remains, but collective charging costs rise. This is a key policy consideration: heavily incentivized mass V2G adoption may erode its own economics. (Source - Nagel et al V2G Nordic Balmorel 2024)

Synergy with transmission: V2G and cross-border transmission capacity are complementary — more interconnection increases V2G utilization and value.

Swedish regulatory grey area

No direct legal barrier exists to discharging an EV battery into the grid. However, several unresolved grey areas create practical obstacles: (Source - Power Circle V2X Synthesis 2024, Source - KTH Thesis V2G Sweden 2024)

Classification ambiguity

An EV connected for V2G can be treated as either:

1. Microproduction facility (mikroproduktionsanläggning) — treating the EV+wallbox combination as equivalent to solar panels or a home battery. This is the approach tested in the PAVE pilot (Göteborg Energi). Implication: changing the vehicle requires updating permits and re-registration, which creates friction for normal vehicle replacement cycles.
2. Mobile injection point — treating the EV as a resource that can inject power at different locations. This would enable cross-location V2G but conflicts with existing requirements for a fixed physical address.

Different network operators have given different answers when asked which classification applies.

Double taxation (dubbelbeskattning)

Electricity charged into an EV battery incurs energiskatt (energy tax) and moms (VAT). If that electricity is subsequently discharged via V2G and sold to another customer, the receiving customer is taxed again on the same kWh.

Skatteverket has introduced a refund mechanism (allowing consumers to reclaim the energy tax on electricity fed back to the grid). However, the refund applies only when discharging to the same concessionary network (koncessionsområde) in which the electricity was originally charged. A consumer who charges in one area and discharges in another (e.g., work in SE3, discharge at home in SE4) loses the refund right. This constrains cross-area V2G and is a specific barrier for mobile use cases. (Source - KTH Thesis V2G Sweden 2024)

Physical address registration

Svenska kraftnät requires a registered physical address for participation in ancillary services markets. DSOs similarly require a known location for local flexibility market participation. EVs are inherently mobile — they cannot easily maintain a single registered location while providing services from multiple physical locations without re-registration at each new site. This limits V2G to a de facto single fixed location per vehicle registration. (Source - KTH Thesis V2G Sweden 2024)

Network code gaps

Swedish nätkoder (network codes) have not been adapted for mobile resources. Connection agreements, measurement, and settlement procedures assume fixed installation points. No standardized procedure exists for a resource that changes location.

Swedish pilots

The Vattenfall/Energy Bank/VW pilot is, by Vattenfall’s own description, one of the world’s largest bidirectional charging pilots at launch (~200 chargers, SE3/SE4, running to 2028). Vattenfall acts as both BRP and BSP, trading aggregated flexibility across the Balancing Market, Nord Pool, and local flexibility markets. VW ID. models with 77 kWh+ batteries are the primary vehicle platform; a September 2026 Vattenfall explainer says participants drive Volkswagen, VW commercial vehicles, Skoda or CUPRA. The same piece gives the reasons for SE3/SE4 as northern hydro plus insufficient transfer capacity southwards, says the Hudiksvall pilot showed charging can be steered from grid frequency (its limit: eight cars at one customer), and says Vattenfall also trades against the spot price, discharging at high prices and charging at low ones. Vattenfall’s claim that price peaks would be visibly cut at 200,000 to two million customers is a projection, not a result. (Source - Vattenfall Energy Bank VW V2G Pilot 2025-2026)

How V2G earnings are being pitched (September 2026): an opinion column by a Nibe energy economist claims VW-group EVs can start earning from October, citing Energy Bank’s founder for “over 20,000 kr/year” and putting household earnings at 500–2,000 kr/month; it cites no measured data and the author’s employer has a commercial interest. The Stenberg/Hudiksvall pilot figures in this vault are either unconfirmed (~27,000 SEK/charger/year from FCR, see the table above) or small and short-period (just over 9,000 kr saved in March–April 2025, per energi.se); there is no measured multi-month earnings figure comparable to the column’s. (Source - Placera Hemberg Snart Kan Du Tjäna 20 000 kr på Din Elbil (2026)) The closest modelled figure, a Chalmers optimisation within the PAVE project, reaches savings of that order only under idealised assumptions: direct access to FCR-N for a single car, perfect foresight and 2025 reserve prices (see Economic under Barriers below).

The first V2G delivery to a local flexibility market in Sweden (and reportedly the world) came in March 2025 — four Volvo Cars EVs delivered 111 kWh to Effekthandel Väst. This was a direct Göteborg Energi–Volvo Cars pilot (launched autumn 2023, using Volvo’s own department vehicles), not an aggregator delivery — a correction to this wiki’s earlier text, which had incorrectly credited CheckWatt. See Effekthandel Väst › V2G breakthrough (March 2025).

PAVE is the project behind the Malakhatka service blueprint below — the same Vinnova grant, the same partner list (Polestar, Vattenfall, Göteborg Energi, Svenska kraftnät, Easee, Chalmers). The wiki previously treated PAVE (in this table) and the Malakhatka service-blueprint research (below) as unconnected; they are the same effort. (Source - Så Kan V2G Gå Från Projektform Till Marknaden (2025)) The same project’s economics strand is a Chalmers optimisation of household V2G across spot, FCR-N and FCR-D (Source - Ramasan et al To V2G or Not Residential (2026)).

Öresundskraft’s HQ pilot started as a smaller, earlier-stage entry than the Vattenfall/Energy Bank/VW national scale-up, using the same Energy Bank aggregation platform. Five charging points are confirmed operational, covering roughly a quarter of the office’s peak power demand — this figure comes directly from Öresundskraft’s own LinkedIn account, not an unverified third-party claim. As of ~July 2026, Energy Bank has begun commercializing the technology together with Volkswagen, and Öresundskraft describes itself as moving from testing to an offering phase, though its standalone FAQ page still reads as pre-commercial. (Source - Öresundskraft V2G Helsingborg Pilot (2025))

V2G as a multi-actor service system

Research increasingly frames V2G not as a technology problem but as a service design challenge — a complex end-to-end service system requiring coordination across users, service providers, and grid actors. A 2026 Chalmers/Polestar/Vattenfall/Göteborg Energi/Svk co-design study (the same PAVE project referenced in the pilots table above) mapped the full service lifecycle across nine phases via stakeholder co-design workshops, and identified a “pre-qualification dead zone” (a further 1–5 months of test and pre-qualification after 3–6 months of hardware commissioning) as a profound service-delivery friction. Full blueprint, phase table, and service design findings on V2G Service Design — The Malakhatka Blueprint.

Barriers

Regulatory and policy

• Absent regulatory framework for V2G — no clear rules; cautious business response
• Double taxation for cross-area V2G discharge
• Physical address registration requirement (Svk, DSOs)
• Classification ambiguity (EV as microproduction vs mobile injection point)
• Nätkoder not adapted for mobile resources
• No EV-specific incentive scheme equivalent to solcellsstöd (solar subsidy) or hembatteriavdrag (home battery deduction)
• Politicians’ knowledge of V2G is low; general interest has not translated into legislative action
• Coordination problem across independent actors: EVSE makers, DSOs/aggregators, OEMs, and EV owners each say they are ready and are waiting on the others — practitioners cite the government’s earlier convened effort to fix EV-charging-app fragmentation as the template a similar V2G coordination push would need. (Source - Så Kan V2G Gå Från Projektform Till Marknaden (2025))

Technical

• Software restriction: many vehicles technically V2G-ready but OEM-locked
• AC bidirectional communication protocols incomplete (no SOC data in AC standard)
• Grid code compatibility across regions/countries uncertain
• Battery degradation impact uncertain — contrasting research findings. A 2026 Chalmers optimisation of one Gothenburg household finds that V2G can lower ageing compared with plain direct charging: about 4.1 % in the year under direct charging, because the car sits at high state of charge, against 2.7 % with spot trading, where the extra cycling adds less wear than the lower average charge removes; reserve markets age slightly more than spot, and higher spot-price volatility raises ageing (Ramasan et al. 2026, a preprint)
• LV network stress: FlexAbility Monte Carlo simulations show that V2G + PV penetration begins causing substation overloads at 30–80% penetration depending on network (see below)

Economic

• Weak consumer revenue case, and the two headline figures aren’t measuring the same thing: 7–14 SEK/year per vehicle net of battery degradation cost, from a Swedish car-sharing-pool study (Søgaard Vallinder and Carlsson, 2022), vs. 378 EUR/year gross arbitrage revenue with no degradation deducted, from a European pool-optimization study (Tepe et al., 2022). Neither study breaks results down by EV model, though degradation cost presumably varies with battery chemistry and capacity. (Source - KTH Thesis V2G Sweden 2024) A third figure, from a single household rather than a pool, is far higher: a 2026 Chalmers optimisation of a Gothenburg house (SE3, 2025 prices, Göteborg Energi tariffs) cuts the annual electricity bill from 32,378 SEK with direct charging to 2,342 SEK by trading spot, FCR-N and FCR-D, and to a net income of 18,250 SEK a year if the owner works from home. Almost all of the gain comes from FCR-N (about 11,700–21,000 SEK a year depending on how long the car is plugged in), and 2022 reserve revenue was at least 50 % above 2025’s. It is an upper bound: the model lets the household bid FCR directly despite Svk’s 0.1 MW minimum, assumes perfect foresight and that every bid is accepted, and leaves out the charger and aggregator’s share (Ramasan et al. 2026, a preprint, not peer reviewed).
• Bidirectional wallboxes ~2× cost of unidirectional
• Battery warranty risk borne by OEMs — caps on V2G cycling energy (VW imposes limits)
• Business model vacuum: revenue split between OEM, aggregator, energy company, grid operator undefined

Social

• Installed base problem (Sweden-specific): many Swedish consumers already own non-V2G-compatible wallboxes (7,000–30,000 SEK); upgrade cost is a barrier unique to high-EV-adoption markets
• Behavioral change required: consumers must plug in consistently and maintain charge availability
• Systems must be “plug & play” — complexity prevents mass adoption

Heavy-duty depots. The ICCT and Fraunhofer ISI truck-charging model (ICCT and Fraunhofer ISI analysis) covers only electric trucks above 12 tonnes and does not model controlled charging or vehicle-to-grid and vehicle-to-building at depots; the authors list them as future work on the flexibility of truck charging. It therefore says nothing about V2G potential from heavy vehicles.

LV network impacts

FlexAbility (2025) used Monte Carlo simulation (Plexigrid platform) to study how increasing V2G penetration combined with rooftop solar affects residential LV networks during FCR-D upregulation service (~58 activation hours/year). Two Swedish networks studied:

Both Stockholm-suburb constraints occurred on weekends in Q3 (low residential load + high solar + V2G activation), named the critical window in both networks (the southern network’s feeder overcurrent came on Q2 weekdays at midday). The 2.7× range in substation-overload thresholds (2.25× for overvoltage) between two Swedish networks underlines that V2G grid impact is highly network-specific — national averages are unreliable. V2G without smart charging coordination risks destabilizing LV grids while stabilizing the transmission network. (Source - FlexAbility Delrapport 3 (2025))

Ecosystem actors

The Swedish V2G ecosystem requires unprecedented cross-sector collaboration: (Source - KTH Thesis V2G Sweden 2024)

OEM fleet aggregation opportunity: if an OEM aggregates its entire sold EV fleet into a BSP portfolio, it could potentially exceed Svenska kraftnät‘s 100 MW threshold for ancillary service participation — making a vehicle manufacturer a major flexibility market actor. This is described as a first-mover strategic opportunity in the KTH thesis. (Source - KTH Thesis V2G Sweden 2024)

Relationship to other wiki topics

• Demand Response — V2G is a major future DR resource; aggregated EV charging and discharging is a key category
• Aggregation — V2G assets require aggregation to reach market thresholds; the first Swedish LFM V2G delivery was a direct Göteborg Energi–Volvo Cars pilot, not an aggregator delivery (see correction above); BSP/BRP structure critical
• Energy Storage — V2G is mobile distributed battery storage; complementary to stationary BESS; 5,000 MW potential by 2030 per FlexAbility
• Balancing Markets — V2G can participate in FCR, aFRR, mFRR once regulatory barriers resolved
• Flexibility Market — EVs are a natural DSO local flex resource (large loads, predominantly daytime-parked)
• Svenska kraftnät — physical address requirement and 100 MW BSP threshold are the key Svk-level barriers
• Villkorade Avtal — flexible connection agreements could accommodate V2G charging; relevant to DSO connection design
• Generator Connection Requirements — ACER Rec 03-2023 (NC RfG 2.0 / NC DC 2.0) explicitly brings V2G into scope of EU connection requirements for the first time
• V2G Grid Risks — DSO and TSO Hazards from Bidirectional EV Charging — synthesis of the five DSO/TSO risk categories: LV overvoltage/thermal overload, unintentional islanding, protection-relay degradation, coordinated fleet cybersecurity, and cold-load pickup
• V2G Service Design — The Malakhatka Blueprint — nine-phase multi-actor service blueprint; the pre-qualification dead zone; user-facing service design findings

Data gaps

• Harmonic distortion and power quality impacts from bidirectional V2G inverter operation on LV networks — no Swedish study covers this quantitatively; relevant to DSO grid code compliance for consumer-grade chargers
• Whether PAVE’s ~20-vehicle scale-up and Polestar 3 fleet phase produce an updated Malakhatka-style service blueprint, or remain undocumented beyond press coverage
• Exact ancillary-service product the Ferroamp/Varberg Energi/Volvo Penta electric-boat pilot (August 2026) qualifies for, and whether it scales beyond the initial two boats
• Skatteverket position on energy tax refund for V2G: is a cross-area solution being considered?
• Ei position on EV classification (microproduction vs mobile injection) — official guidance or statement
• Svk position on physical address requirement for mobile V2G resources — any planned reform
• Results from the 2026–2028 national Vattenfall/Energy Bank/VW scale-up (200 chargers, SE3/SE4) — the larger scale-up’s own results remain pending (the preceding Stenberg/Hudiksvall pilot has no confirmed earnings figure in any raw; see the table above)
• OEM commercial V2G (grid-facing) launch timelines for the Swedish market — Volvo and Polestar both launched commercial V2H (vehicle-to-home only, not grid-facing) in November 2025, but for the US market exclusively (Polestar 3 in California; Volvo EX90 nationwide US), via a third-party Ara Home Energy Station (Dcbel); no Sweden availability or date found for either V2H or V2G. Polestar remains an active Vinnova project partner (2023-00785) on the Gothenburg V2G pilot as of May 2026, but that is still pilot-stage, not a commercial product
• Pre-qualification timeline data from live Swedish V2G pilots — the 1–5 month TSO pre-qualification delay identified in service blueprint co-design; quantification from actual deployments would confirm or refine this estimate