Key Takeaways
- V2H allows an EV battery to power a home directly — no grid export involved
- A typical 70 kWh EV battery can power an average home for 2–3 days during an outage
- Simpler than V2G — no utility interconnection agreement required in most jurisdictions
- Paired with solar, V2H enables true energy independence during grid outages
- Requires a bidirectional charger and a transfer switch or smart panel to isolate from the grid
- Can reduce electricity costs by powering the home from the EV during peak TOU rate hours
What Is Vehicle-to-Home (V2H)?
Vehicle-to-Home (V2H) is a bidirectional energy flow technology that allows an electric vehicle to discharge its battery to power a home’s electrical loads. Unlike Vehicle-to-Grid (V2G), which exports energy to the utility grid, V2H operates behind the meter — the energy stays within the home’s electrical system and never reaches the grid.
V2H serves two primary use cases. First, it provides backup power during grid outages, turning the EV into a mobile generator that can keep lights, refrigeration, medical equipment, and other critical loads running for days. Second, in markets with time-of-use electricity rates, V2H allows homeowners to power their home from the EV during expensive peak hours after charging the EV from solar or cheap off-peak grid electricity.
A fully charged Ford F-150 Lightning with its 131 kWh battery can power an average American home for up to 3–4 days during an outage. That’s more capacity than most dedicated home battery systems at a fraction of the incremental cost.
How V2H Works
V2H systems connect the EV battery to the home’s electrical panel through specialized hardware:
Bidirectional Charger
A V2H-capable charger (also called a bidirectional EVSE) connects to both the EV and the home’s electrical panel. It handles AC-DC conversion in both directions — grid AC to battery DC during charging, and battery DC to household AC during discharge.
Transfer Switch or Smart Panel
An automatic transfer switch (ATS) or smart electrical panel isolates the home from the grid during V2H discharge. This prevents backfeeding electricity to the grid (which could endanger utility workers) and is required by electrical code.
Load Management
The V2H system prioritizes which circuits receive power. Critical loads (refrigerator, lights, internet, medical equipment) are powered first. High-draw loads (HVAC, electric stove, dryer) may need to be managed or excluded depending on the charger’s output capacity (typically 7–19 kW).
Solar Integration (Optional)
When paired with a solar PV system, the EV charges from solar during the day and discharges to the home in the evening or during outages. This creates a solar-plus-storage system using the vehicle’s existing battery instead of a separate home battery.
Battery Management
The EV’s battery management system (BMS) enforces minimum state-of-charge limits — typically 20% — to ensure the driver retains enough range for emergency transportation. Users can configure departure times and minimum charge levels.
Hours of Backup = (Usable Battery Capacity × Discharge Efficiency) / Average Home Load (kW)V2H vs. Dedicated Home Batteries
Homeowners considering backup power and energy management have two main options. Here’s how they compare:
| Factor | V2H (EV as Battery) | Dedicated Home Battery |
|---|---|---|
| Usable Capacity | 50–120 kWh (vehicle dependent) | 10–20 kWh (typical residential) |
| Incremental Cost | $1,500–4,000 (charger + transfer switch) | $10,000–18,000 (battery + installation) |
| Availability | Only when car is home and plugged in | Always available |
| Discharge Power | 7–19 kW | 5–11 kW |
| Warranty Impact | May affect EV battery warranty | Dedicated warranty (10–15 years) |
| Backup Duration | 2–4 days (typical home) | 8–16 hours (single battery) |
| Solar Integration | Requires compatible charger | Native integration with most solar inverters |
When designing solar systems for customers with V2H-capable EVs, the EV effectively replaces the need for a separate home battery in many scenarios. Use solar design software to model the customer’s load profile against V2H availability — if the car is typically home by 5 PM, it can cover the evening peak period in most TOU markets.
V2H-Compatible Vehicles and Chargers
Not all EVs support bidirectional power flow. As of 2026, the following vehicles offer V2H capability:
Ford F-150 Lightning
131 kWh battery (Extended Range). Up to 9.6 kW output via Ford Charge Station Pro. Powers a home for 3–4 days. The most complete V2H solution currently available in the U.S. market.
Hyundai Ioniq 5/6
77.4 kWh battery. V2L (Vehicle-to-Load) output via exterior outlet, V2H via compatible bidirectional charger. 3.6 kW output via built-in outlet, higher via external bidirectional EVSE.
Nissan Leaf
40–62 kWh battery. Pioneer of V2H via CHAdeMO bidirectional charging. Widely used in Japan’s V2H market. Requires CHAdeMO-compatible bidirectional charger.
Other Manufacturers
BMW iX, VW ID.4, Kia EV6/EV9, and others are adding bidirectional capability via ISO 15118-20. GM’s Ultium platform is rolling out V2H across Chevrolet, GMC, and Cadillac EVs.
Practical Guidance
V2H is a practical technology that solar professionals should understand and offer as part of comprehensive energy solutions:
- Size solar for EV + home load. When the EV will charge from solar, add 2,500–4,000 kWh/year to the home’s base consumption. Use solar software to model the combined load and right-size the array.
- Identify critical load circuits. Work with the customer to define which circuits should receive V2H backup power. Design the transfer switch configuration to prioritize these loads.
- Account for V2H charger placement. The bidirectional charger should be located near the main electrical panel to minimize wiring runs and voltage drop. Factor this into the garage or carport design.
- Model TOU savings with V2H. In TOU markets, show the customer how charging the EV during off-peak/solar hours and discharging to the home during peak hours reduces their electricity bill. The financial modeling tool should capture this interaction.
- Install a code-compliant transfer switch. NEC Article 702 governs optional standby systems. An automatic transfer switch (ATS) or listed smart panel must isolate the home from the grid during V2H discharge. This is non-negotiable for safety and code compliance.
- Verify panel capacity. The main electrical panel needs sufficient amperage for both the charging load (30–60A circuit) and the V2H backfeed. Panels under 200A service may need an upgrade.
- Test the full backup sequence. After installation, simulate a grid outage by opening the main breaker. Verify that the transfer switch activates, the EV begins discharging, and critical loads receive power within the expected transition time.
- Educate the homeowner. Walk the customer through the V2H interface — how to set minimum charge levels, schedule discharge windows, and manually activate backup mode. Provide written instructions for reference during actual outages.
- Position V2H as a cost-effective alternative to home batteries. A V2H setup costs $1,500–4,000 (charger + transfer switch) versus $10,000–18,000 for a dedicated home battery, while offering 3–6x the capacity. This resonates with budget-conscious customers who already own or plan to buy an EV.
- Lead with backup power in storm-prone areas. In regions with frequent outages (Florida, Texas, Northeast), V2H’s days-long backup capability is a strong selling point. Frame the solar + EV + V2H combination as a complete energy resilience solution.
- Bundle with solar proposals. When a customer mentions they have or are considering an EV, immediately add V2H to the solar proposal. The marginal cost is small and it differentiates your offering from competitors selling solar-only systems.
- Address the “what if I need my car” concern. Customers worry about draining their EV during an outage and being unable to drive. Explain that the BMS enforces a configurable minimum charge (e.g., 20% = 50+ miles of range) and that solar can recharge the EV during daylight hours even during a grid outage.
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Real-World Examples
Hurricane Backup: Florida Homeowner
A homeowner in Tampa with a 10 kW solar system and Ford F-150 Lightning experienced a 4-day grid outage after a hurricane. The V2H system powered critical loads (refrigerator, well pump, lights, internet, phone charging) at an average draw of 1.5 kW. With 100 kWh of usable battery capacity and 30–35 kWh/day of solar recharging during partially cloudy conditions, the EV maintained enough charge to power the home continuously and still had 40% battery remaining when grid power was restored.
TOU Savings: California Homeowner
A customer in San Jose on PG&E’s E-TOU-D rate plan uses V2H to shift energy consumption. Their 8 kW solar system charges the Hyundai Ioniq 5 during midday off-peak hours. From 4–9 PM (peak rate: $0.58/kWh), the EV discharges 10 kWh to the home, saving approximately $5.80/day. Over a year, V2H TOU arbitrage adds $1,750 in savings beyond what the solar system alone provides — paying for the bidirectional charger within 2 years.
Whole-Home Backup: Texas Homeowner
During the February 2025 winter storm in Texas, a homeowner with a 12 kW solar system and GM Silverado EV used V2H to power the entire home including heat pump operation. The 200 kWh battery (150 kWh usable) supported 3 kW average draw for 50 hours before the grid returned. Solar generation during the cold but sunny days provided 15–20 kWh of supplemental charging, extending the backup window.
Frequently Asked Questions
What is Vehicle-to-Home (V2H)?
Vehicle-to-Home (V2H) is a technology that lets an electric vehicle’s battery supply power directly to a home. Using a bidirectional charger and transfer switch, the EV can power household circuits during grid outages or during expensive peak electricity hours. Unlike V2G, V2H does not export energy to the grid — it stays within the home’s electrical system.
How long can an EV power a house?
It depends on the EV’s battery size and the home’s power consumption. An average U.S. home uses about 30 kWh/day. A typical 70 kWh EV battery (with 80% usable capacity = 56 kWh) can power that home for roughly 1.5–2 days on critical loads only (at reduced consumption of 15–20 kWh/day, backup extends to 2.5–3.5 days). Larger batteries like the Ford F-150 Lightning Extended Range (131 kWh) can last 3–4 days. If paired with solar panels that recharge the EV during the day, backup can be extended indefinitely.
Is V2H cheaper than a home battery?
Yes, if you already own a V2H-capable EV. The incremental cost of a bidirectional charger and transfer switch is $1,500–4,000, compared to $10,000–18,000 for a dedicated home battery like the Tesla Powerwall or Enphase IQ Battery. The EV also typically provides 3–6 times more storage capacity. The trade-off is that V2H backup is only available when the car is home and plugged in, while a dedicated battery is always available.
Can V2H work with solar panels?
Yes. Solar + V2H is a powerful combination. During normal operation, solar panels charge the EV during the day while powering the home. In the evening, the EV discharges to power the home during peak rate hours. During grid outages, solar can continue recharging the EV (if the solar inverter supports backup mode), extending backup duration indefinitely. This creates a self-sustaining energy system without the cost of a separate home battery.
About the Contributors
CEO & Co-Founder · SurgePV
Keyur Rakholiya is CEO & Co-Founder of SurgePV and Founder of Heaven Green Energy Limited, where he has delivered over 1 GW of solar projects across commercial, utility, and rooftop sectors in India. With 10+ years in the solar industry, he has managed 800+ project deliveries, evaluated 20+ solar design platforms firsthand, and led engineering teams of 50+ people.
Content Head · SurgePV
Rainer Neumann is Content Head at SurgePV and a solar PV engineer with 10+ years of experience designing commercial and utility-scale systems across Europe and MENA. He has delivered 500+ installations, tested 15+ solar design software platforms firsthand, and specialises in shading analysis, string sizing, and international electrical code compliance.