Solar with EV Charging
Home EV charging adds meaningful electrical load. Planning it alongside solar generation - and optionally battery storage - helps avoid undersized infrastructure and missed integration benefits.
Why plan solar and EV charging together
An EV may increase your household electricity use by 2,000-4,000 kWh per year depending on mileage - a significant addition. Installing a charger without considering solar capacity, battery storage or main fuse rating can create bottlenecks.
Conversely, if you install solar first without leaving capacity for a future charger, you may need additional consumer unit work later.
Three charging strategies
1. Charge when parked during daylight
If your car is home during solar generation hours - for example when working from home - surplus solar can flow directly to the charger. This works best with a solar-aware charger or energy management system.
2. Charge overnight from the grid
Many EV owners charge overnight on off-peak tariffs. Solar does not contribute directly, but lower grid rates may still make this economical. Battery storage can separately cover evening household load.
3. Store solar in battery, charge car later
A battery can store daytime solar for evening use - including partial EV top-up. Whether this is practical depends on battery capacity, car battery size and daily driving distance.
We do not claim that solar will fully power your EV or eliminate charging costs. Actual outcomes depend on generation, driving patterns, equipment and tariff - subject to survey.
Load management essentials
EV chargers draw 7 kW or more - comparable to an electric oven or shower. Combined with other appliances, this can approach your main fuse limit. Dynamic load management reduces charger output when household demand is high, protecting your supply.
Electrical infrastructure should be assessed before installation. This includes confirming your main fuse rating with your installer and, where necessary, the distribution network operator.
Equipment compatibility
Not all chargers integrate with all solar inverters. When specifying equipment, confirm:
- Whether the charger supports solar diversion or surplus charging
- Whether your inverter brand offers compatible energy management
- Whether a third-party platform is needed to coordinate solar, battery and EV
- Monitoring visibility - can you see solar, battery and charging data in one place?
Second EV considerations
If a second EV is likely within a few years, discuss dual charger capacity or load-managed single chargers with expansion options during your initial survey. Retrofitting a second charger later is possible but may involve additional trenching or consumer unit work.
Frequently asked questions
Summer's longer generation hours make daytime solar charging more practical, while winter often relies more on overnight grid charging or stored battery power. The three charging strategies above apply differently depending on the season, and your installer should explain these seasonal trade-offs rather than presenting a single annual figure.
Not necessarily, but a solar-aware or energy-management-compatible charger makes it easier to prioritise surplus solar generation for charging rather than drawing from the grid. Confirm compatibility with your specific inverter and charger brands during your survey.
Solar surplus can be directed to more than one charger if your energy management system supports it, but on any given day there is only so much surplus to allocate. In practice, this usually means one vehicle gets priority for solar charging while the other draws more from the grid, unless generation is unusually high.
It depends on your driving pattern and when you charge. A battery can store daytime solar for evening EV top-up, but whether this is worthwhile depends on battery capacity, car battery size and daily mileage. See our battery storage page for general suitability, or our battery storage sizing guide for how this interacts with EV charging.
Load management, or dynamic load management, automatically reduces EV charger output when household demand is high, helping protect your main fuse rating from being exceeded. It is a common feature on modern chargers rather than an optional extra for most installations.
Your main fuse rating and consumer unit capacity, cable routing between the charger and consumer unit, inverter and charger compatibility, and whether load management is needed. These should all be assessed during a technical survey, not estimated remotely.