V2G Potential in Numbers: What can your car really return to the grid?
This calculator estimates the annual V2G benefit from energy arbitrage + optional capacity premiums, subtracts simple battery wear costs, and shows you payback & CO₂ impact. An ideal lead magnet that provides instant results without technical jargon.
A simple balance: Discharge "displaces" grid power, charging causes emissions based on your green share.
How this calculator works (Brief Explanation)
The calculator uses three components: Energy, Money, and Wear. First, it determines how much energy you can discharge per V2G session. This uses the discharge power (kW) × duration (h). This value is automatically capped by the usable battery window: Battery Capacity × "Usable for V2G". This prevents unrealistic energy outputs that your battery cannot actually deliver.
Next is the financial side: For the discharged energy, you receive the selling price ($/kWh). To refill the battery, you must charge more than you discharged due to losses. The round-trip efficiency accounts for this: Energy_In = Energy_Out / Efficiency. Charging energy is valued at the charging price. The difference is the raw energy arbitrage. The calculator then adds any optional capacity premium ($/kW/month) you might receive.
Then comes the often-overlooked point: Battery wear. We estimate this via "Equivalent Full Cycles": Annual Export (kWh) / Battery Capacity (kWh) = Full Cycle Equivalent. These cycles are assigned a cost budget per cycle: Battery Replacement Cost / Warranty Full Cycles. This results in an annual wear cost estimate. Note: This is a simplification. Temperature, SoC window, C-rate, and chemistry play significant roles in reality, but this "rule of thumb" is great for comparing scenarios.
Payback shows how many years it takes for hardware & installation to amortize based on your net profit after wear. If net ≤ 0, payback is shown as "not feasible". Use this as a decision and discussion aid, not as a legally binding forecast.
FAQ (Visitor Information)
1) Do I need a specific EV for V2G?
Yes. The vehicle, on-board charger/communication, and the wallbox/inverter must all support V2G. Many cars currently only support V2L/V2H or are software-limited.
2) What is the biggest lever for profit?
The price spread (Sell – Buy) plus any possible capacity premium. If you can charge cheaply (night/solar) and discharge at high prices (peak), the benefit increases sharply.
3) Does V2G damage the battery?
Additional cycles fundamentally increase wear. How much depends on chemistry, temperature, SoC window, and power. This is why this calculator intentionally includes a wear reserve.
4) What does "Usable for V2G (%)" mean?
This is your chosen operating window. Many users leave a buffer, e.g., 20–80% SoC, so that daily range and battery health remain balanced.
5) Why must I charge more than I discharge?
Due to conversion and storage losses. The round-trip efficiency summarizes charging and discharging losses. At 88%, you must charge about 11.36 kWh for a 10 kWh discharge.
6) Is the CO₂ balance always positive?
Not necessarily. If you charge with "dirty" grid power and displace the same mix later, the benefit is minimal. With solar or green power during charging, it becomes significantly better.
7) Why is the result only an estimate?
Tariffs, grid regulations, grid fees, taxes, aggregator fees, and technical limits vary. This calculator is intended to make scales and sensitivities visible.
Vehicle-to-Grid: 3-Part Calculation
V2G (Vehicle-to-Grid) lets a bidirectional EV feed energy back into the public grid. The calculator models three components — energy flow, financial return, and battery wear — to give you a realistic net profit estimate:
- Energy ComponentDischarge Power (kW) × Session Duration (h) = Discharge per Session. Capped by Battery Capacity × Usable for V2G %. To refill: Energy_In = Energy_Out ÷ Round-Trip Efficiency. Annual export = sessions per year × discharge per session.
- Financial ComponentRevenue = Annual Export × Sell Price ($/kWh). Charging Cost = Energy_In × Charging Price. Any capacity premium ($/kW/month × inverter kW × 12) is added. Raw Profit = Revenue + Premium − Charging Cost.
- Battery Wear ComponentAnnual Full Cycle Equivalent = Annual Export ÷ Battery Capacity. Wear Cost/Year = (Battery Replacement Cost ÷ Warranty Full Cycles) × Annual Cycles. Net After Wear = Raw Profit − Wear Cost/Year.
Payback = V2G Hardware Cost ÷ Net After Wear per Year. If Net ≤ 0, V2G is shown as "not feasible" at current parameters.
When V2G Makes Financial Sense
Profitability hinges almost entirely on the spread between your charging price and the sell price. Here are typical European scenarios as of 2025:
| Scenario | Charge at | Sell at | Spread | Profitability |
|---|---|---|---|---|
| PV + Dynamic Tariff (DE) | 0–5 ct/kWh (solar surplus) | 8–12 ct/kWh (feed-in) | 3–12 ct | Moderate |
| Night Tariff + Peak Sale | 18–24 ct/kWh (night) | 28–38 ct/kWh (peak) | 4–20 ct | Good (if available) |
| Standard Tariff + Feed-in | 28–38 ct/kWh | 6–10 ct/kWh | −22 to −28 ct | Loss-making |
| Capacity Premium Only (DE) | any | +Premium Program | Program-dependent | Requires contract |
Key rule: V2G is only profitable if your effective charging price is significantly lower than the sell price. Charging from the standard grid and selling at feed-in tariff rates almost always results in a loss after wear costs.
V2G vs. V2H: Which Is Right for You?
| Aspect | V2G (Vehicle-to-Grid) | V2H (Vehicle-to-Home) |
|---|---|---|
| Energy goes to | Public electricity grid | Your own household |
| Revenue model | Sell energy to grid, earn $/kWh or capacity premium | Avoid buying from grid, save $/kWh you would have paid |
| Hardware required | Bidirectional charger + V2G-capable wallbox + grid agreement | Bidirectional charger + compatible inverter (simpler) |
| Grid connection | Must be approved and registered with grid operator | Not required (internal use only) |
| Setup cost | 3,000–8,000 € (hardware + installation + approval) | 1,500–4,000 € (hardware + installation) |
| Benefit type | Active income (you sell energy) | Passive savings + blackout resilience |
| Battery wear concern | High (many extra cycles) | Moderate (controlled usage) |
| EV compatibility (2025) | Very limited: Nissan Leaf, some Kia/Hyundai | Wider: many EVs with CHAdeMO / ISO 15118-20 |
Frequently Asked Questions
How accurate is the battery wear estimate?
It is a useful approximation, not a precise battery model. Real battery degradation depends on temperature, depth of discharge, C-rate (charge/discharge speed), battery chemistry, and SoC operating range — none of which the calculator models in detail. The "replacement cost ÷ warranty cycles" method is a commonly used rule-of-thumb that gives a reasonable order-of-magnitude cost per cycle. Use it to compare scenarios, not as a warranty or engineering forecast.
Do I need a special EV for V2G?
Yes. The EV, its on-board charger, and the wallbox/inverter must all support bidirectional charging via a compatible protocol (typically CHAdeMO or ISO 15118-20). As of early 2026, most EVs do not support V2G commercially. Notable exceptions: Nissan Leaf (CHAdeMO), Kia EV6, Hyundai Ioniq 5/6, and some BYD models in certain markets. Software-locked V2G is a known limitation for many OEM platforms.
What is the capacity premium and how do I enter it?
A capacity premium is a payment from a grid operator or aggregator for having your battery available for frequency regulation or grid stabilization, typically paid as $/kW of capacity per month regardless of how much you actually discharge. If you have such a contract, enter the monthly rate in the optional "Capacity Premium" field. If not, leave it at 0 — it does not affect the core energy calculation.
Can I use both V2G and V2H with the same vehicle?
In theory yes, but the use cases are in tension: V2G typically requires exporting to the grid (lower feed-in tariffs but more sessions), while V2H focuses on self-consumption. Most practical setups prioritize one mode. Some advanced home energy management systems (e.g., SolarEdge, Victron) can dynamically switch between modes, but this requires compatible hardware throughout the entire chain.
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