Solar + Battery + EV: Designing the Complete Singapore Home Energy System
A complete Singapore home energy system combining solar, battery storage, and EV charging costs S$55,000 to S$75,000 for a 15kWp solar + 13.5kWh battery + 7kW charger configuration. Combined annual savings from electricity and fuel replacement reach S$9,000 to S$12,000 with a 6 to 8 year payback.
Key Takeaways
- 1
Add 3 to 5kWp of solar for every EV in the household to cover average Singapore EV driving distance from solar generation
- 2
A 15kWp solar + 13.5kWh battery + 7kW EV charger system costs approximately S$55,000 to S$75,000 all-in and delivers combined annual savings of S$9,000 to S$12,000
- 3
Vehicle-to-home (V2H) technology that uses the EV battery to power the house is available in Singapore from select brands but requires compatible hardware on both the car and the charger
Solar, battery storage, and an electric vehicle are individually viable investments for a Singapore landed homeowner. Together, they form an integrated energy system where each component makes the others more economical, solar charges the battery, the battery extends daytime self-consumption into the evening, and the EV adds a large overnight load that solar and battery can service without drawing from the grid. Getting the design right requires sizing each component relative to the others, not just installing all three independently.
Sizing Solar for an EV Household
The average Singapore EV driver covers approximately 25,000 km per year, consistent with data from the Land Transport Authority on passenger vehicle annual mileage. An EV using 15 kWh per 100 km requires approximately 3,750 kWh per year of charging energy. A solar system generates 1,106 kWh per kWp per year in Singapore. To cover this charging requirement from solar generation, the system needs approximately 3.4 kWp of additional capacity beyond what would serve the household without an EV.
The practical rule: add 3 to 5kWp per EV when sizing your solar system. The range accounts for whether the EV is a compact sedan (Hyundai Ioniq 5: ~14 kWh/100km) or a larger SUV (BMW iX: ~18 kWh/100km). For a household without solar installing for the first time with an EV, the target is a system that covers household consumption plus EV charging, typically 12 to 18kWp for a semi-D or bungalow.
Where Battery Storage Fits in the System
Battery storage bridges the timing mismatch between solar generation (mostly 8am to 5pm) and EV charging (most commonly overnight, when the homeowner returns from work). Without a battery, EV charging at 11pm draws entirely from the SP Group grid at the full tariff. With a battery that stored daytime solar, the evening charging session draws first from the battery, electricity generated at zero cost from the roof.
For a system designed around EV charging, a battery with 13 to 15kWh of usable capacity (one Tesla Powerwall 3 at 13.5kWh, or two Enphase IQ Battery 5P units at 10kWh combined) covers approximately 87 to 100km of EV range per overnight charge cycle. This is adequate for Singapore's typical daily driving distance of 40 to 80km, with headroom for longer weekend trips.
The battery also serves household resilience during grid outages, with a hybrid inverter, it can maintain power to critical circuits (fridge, internet, selected lights and outlets) for 4 to 8 hours depending on load.
Full System Cost Breakdown
| Component | Specification | Indicative Cost |
|---|---|---|
| Solar array | 15kWp TOPCon panels | S$19,500 |
| Hybrid inverter | 15kW, DC-coupled battery port | S$5,500 |
| Battery storage | Tesla Powerwall 3 (13.5kWh) | S$16,000 |
| EV charger | 7kW AC smart charger | S$2,500 |
| Installation (all 3) | LEW, SP Group, wiring | S$7,000 |
| Total system cost | 15kWp + 13.5kWh + 7kW charger | ~S$50,500 to S$65,000 |
Vehicle-to-Home (V2H): What Is Actually Available in Singapore
V2H allows the EV battery to discharge back into the home's electrical circuits, effectively making the car a large mobile battery. In Singapore as of 2026, V2H is available but requires compatible hardware on both the vehicle and the charger, not all EVs and chargers support it. Brands with V2H capability available in Singapore include Nissan (via CHAdeMO), BYD (via specific charger partnerships), and some Hyundai/Kia models (via bidirectional OCPP chargers).
EMA has engaged with V2H as part of its electric mobility and grid resilience planning. The regulatory framework for V2H in Singapore is evolving, consult with your installer and the specific charger brand about current approval status for any V2H setup before purchasing. A V2H-compatible 7kW AC charger costs approximately S$1,000 to S$2,000 more than a standard AC charger, and the bidirectional inverter functionality adds S$3,000 to S$5,000 depending on the system architecture.
Solar, battery, and EV are not three separate investments. They are one energy system where each component makes the others more efficient. Size them together or you leave money on the table.
The battery storage guide covers the aircon and overnight use question in detail. For your specific property and usage pattern, run the Sunnify estimate tool with your household consumption and EV mileage inputs. The cost guide includes the solar-only component; your installer should price the battery and EV charger as a package.
Further reading: Land Transport Authority EV adoption in Singapore · EMA battery energy storage systems · IEA electric vehicle outlook.
Does adding an EV charger require a new SP Group connection or meter upgrade?
A 7kW AC EV charger draws approximately 7kW from your electrical board, within the capacity of a standard 63A single-phase Singapore residential connection. No SP Group meter upgrade is typically required for a single 7kW charger. A 22kW AC charger (three-phase) would require a three-phase connection if you do not already have one. Confirm your connection capacity with your electrician before purchasing the charger, particularly if you also have a large solar inverter, battery inverter, and pool pump on the same board, the aggregate load may warrant a board upgrade even if the connection capacity is sufficient.
What home energy management systems work well with solar + battery + EV in Singapore?
A home energy management system (HEMS) coordinates generation, storage, and consumption automatically, scheduling EV charging when solar is abundant, pre-cooling the house before peak afternoon heat using stored solar, and optimising battery charge/discharge against the tariff cycle. In Singapore, compatible systems include SolarEdge Energy Hub (if using SolarEdge inverter and charger), Tesla Powerwall with Tesla app scheduling, Enphase Enlighten with EV integration, and brand-agnostic third-party platforms like Loxone or Home Assistant with appropriate integrations. The ecosystem compatibility between your chosen inverter, battery, and charger brands determines which HEMS options are available, discuss this with your installer as a package requirement, not an afterthought.
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What does this mean for your home?
Tariffs and technology change the math. The calculator uses current SP figures to show your actual payback and savings.
