Installing solar PV on your home can be a great investment for any homeowner. You can generate your own electricity, reduce your reliance on the grid and make savings on your electricity bills.
However, as higher users of electricity, electric vehicle (EV) owners could benefit from solar panels even more.
If you charge your EV at home, combining solar panels with your electric vehicle can help reduce both your household electricity costs and the cost of running your car.
Why Do EV Owners Like Solar Panels?
Many owners of electric vehicles have invested in an EV because they want to be kinder to the environment and reduce the cost of running their car.
If these are your motivations, the next step could be to invest in solar panels, as they offer many of the same benefits.
Solar PV systems enable you to generate your own green electricity, making you less reliant on electricity from the national grid, which comes from a variety of energy sources. Solar panels can also help you reduce your electricity bills by allowing you to use more of your own generated electricity.
As an EV owner, if you are charging your vehicle at home, you may have seen an increase in your electricity bills. Charging an electric vehicle can add significantly to household electricity consumption, so reducing the amount of electricity you need to buy from the grid can make a noticeable difference.
Will Solar Panels Work for Me?
A large proportion of homes have suitable roof space for solar panels, provided the roof receives sufficient sunlight and is not significantly affected by shading.
It doesn’t matter whether you have a pitched roof or a flat roof, as there are solar installation options available for most roof types.
What If My Car Isn’t at Home During the Day?
If you commute to work and your electric car is parked elsewhere during daylight hours, you may not be able to use your solar-generated electricity to charge it directly. However, this does not mean solar panels are unsuitable for your home.
There are several ways to benefit from solar generation even when your car is away during the day.
Use solar electricity around your home
Your solar panels can supply electricity to appliances and other household demands while your car is at work. This reduces the amount of electricity you need to import from the grid, even if you cannot charge your vehicle directly from your panels.
Any surplus electricity that you do not use can potentially be exported to the grid, subject to your export arrangement and tariff.
Consider a home battery
A home battery can store some of the surplus electricity generated during the day for use later, when your household demand increases.
Depending on the system configuration, this stored electricity may help power your home in the evening or contribute to EV charging when your car returns. The battery’s usable capacity, charging power and the amount of surplus solar generation will determine how much electricity is available.
A home battery will not necessarily store enough energy to cover both your evening household demand and a full vehicle charge. Its suitability should therefore be assessed against your actual consumption patterns.
Charge your EV overnight
If your car is usually at home overnight, a suitable smart electricity tariff may offer cheaper charging periods. You could use solar generation to reduce daytime household electricity costs and schedule vehicle charging for periods when imported electricity is less expensive.
This approach can be particularly useful during winter, when solar generation is lower and daylight charging opportunities are limited.
The most suitable option will depend on your working hours, annual mileage, household consumption and available electricity tariffs. Solar panels can still offer value when your EV is away during the day, but the financial benefits will depend on how effectively you use the electricity your system generates.
Do You Need a Home Battery to Charge an Electric Car?
A home battery is not essential for charging an electric car with solar panels. You can use available solar electricity directly to charge your vehicle, provided your solar PV system and EV charging equipment are compatible.
However, adding battery storage may help you make better use of the electricity your panels generate, particularly if your car is only at home in the evenings.
The best option depends on your charging routine, household electricity consumption and the cost of importing electricity from the grid.
Solar panels without a home battery
A solar-only system can supply electricity to your home and, when your vehicle is connected, help charge your EV using available solar generation.
This can be a straightforward option if your car is regularly parked at home during daylight hours. However, solar generation varies throughout the day and across the seasons, so you may still need to import electricity when your vehicle requires more power than your panels can provide.
Solar panels with home battery storage
A home battery stores surplus electricity generated by your panels for use later. This can help supply evening household demand and may provide some electricity for EV charging when your car returns home.
The battery needs to be sized around the electricity you can realistically store and use. A larger battery is not automatically the best choice, particularly if your solar system rarely generates enough surplus electricity to fill it.
It is also important to distinguish between the battery’s energy capacity, measured in kWh, and its charging or discharging power, measured in kW. Both can affect how useful it is for your household and EV charging arrangements.
Solar panels with smart-tariff EV charging
For some households, combining solar panels with a smart EV charger and a suitable time-of-use electricity tariff may be more economical than installing a larger home battery.
You can use solar electricity when it is available and schedule additional vehicle charging during cheaper tariff periods. This can help manage charging costs when your car is normally parked at home overnight.
The most suitable setup will depend on your tariff, vehicle charging requirements and how much surplus solar electricity you expect to generate.
Which option is best for your home?
There is no universal answer. Solar panels alone may be sufficient for a household that can charge its EV during the day. A home battery may be useful where there is substantial surplus generation and significant evening electricity demand. Smart-tariff charging can also help reduce costs when overnight charging is more practical.
Before investing in battery storage, consider your annual mileage, when your car is at home, existing household electricity use and the likely savings from each option. A system assessment can help establish whether the additional cost of a battery is justified for your circumstances.
How Much Solar Power Will I Need?
The size of the solar panel system you need will depend on your household electricity consumption, how much you drive your electric vehicle and how much electricity your car uses per mile. Your available roof space, roof orientation and shading will also influence how much electricity your panels can generate.
When planning a solar PV system for a home with an electric vehicle, it is important to consider your combined household and vehicle electricity requirements rather than sizing the installation around your home alone.
How much electricity does an electric car use?
Electric vehicle efficiency varies depending on the model, driving conditions, journey length, weather and driving style. As a simple illustration, a vehicle averaging 3 miles per kWh would use approximately:
- 2,000 miles: 667kWh of electricity
- 5,000 miles: 1,667kWh of electricity
- 8,000 miles: 2,667kWh of electricity
- 10,000 miles: 3,333kWh of electricity
These figures are estimates based on the assumed efficiency and exclude additional charging losses. Your vehicle’s actual consumption may be higher or lower.
This additional electricity demand can make solar panels particularly attractive to EV owners. However, the amount of solar electricity available for charging will depend on when your panels generate electricity and when your car is connected to the charger.
Should you install more solar panels if you own an EV?
If you already have solar panels, buying an electric car may increase your household electricity demand enough to justify expanding your existing system. Before adding panels, assess how much electricity your current installation generates, how much you export to the grid and whether your inverter and roof have sufficient capacity for an expansion.
For homeowners installing solar for the first time, it can be worth planning for anticipated EV charging demand from the outset. This helps ensure the system is designed around your likely future electricity use rather than your current bills alone.
There is no single solar system size that suits every electric car owner. A household with high annual mileage and significant daytime charging demand will have different requirements from a household that drives relatively little and charges overnight.
A properly designed system should balance generation, household consumption, EV charging habits, available roof space and installation costs to help you make the most of your investment.
How Much Could I Save If I Installed Solar Panels?
Let’s take a three-bedroom house in the South East of the UK as an example.
A typical installation size for this property could be a 12-panel solar PV system with 5.12kWh of battery storage. This system could generate approximately 4,728.12kWh per year.
In this example, the household could save £1,008.47 per year, made up of:
- £771.75 in electricity bill savings
- £236.72 in export payments for unused electricity
If this household had medium electricity usage of 3,500kWh per year, and their electricity tariff charged 24.5p per kWh with a standing charge of 60.1p per day, their annual electricity bill without solar would be approximately £1,076.86.
This demonstrates how solar panels can help reduce the amount of electricity you need to purchase from the grid.
How Long Does It Take to See a Return?
You can typically see a return on your investment in 6–10 years, while solar PV systems with battery storage can last for around 30 years.
Based on inflation over the next 30 years, the average annual savings over the system’s lifetime could be £2,431.15.
When we factor in the initial installation costs and any replacement parts during the 30 years, the total savings could be £57,689.37.
For EV owners, there is an additional benefit: the electricity generated by your solar panels can help reduce the amount you spend charging your vehicle, as well as reducing your household electricity costs.
Can Solar Panels Charge an Electric Vehicle?
Yes. Solar panels can generate electricity that can be used to charge an electric vehicle at home.
How much of your EV charging can be powered by solar will depend on factors including the size of your solar PV system, your vehicle’s electricity consumption, how far you drive and when you charge your car.
Adding battery storage can also allow you to store electricity generated during the day and use it later to charge your EV.
Is Solar Worth It If I Have an Electric Vehicle?
For many electric vehicle owners, solar panels can be a worthwhile investment because charging a car at home increases household electricity consumption. Generating your own electricity can reduce the amount you need to buy from your supplier and help manage the cost of running your vehicle.
However, the financial benefit depends on more than the amount of electricity your solar panels generate. It also depends on how much of that electricity you can use directly, your installation costs, the price of imported electricity and any payments you receive for exporting surplus generation.
If your car is usually at home during daylight hours, you may be able to use more solar electricity for charging. If you commute during the day, your panels can still supply household appliances, while battery storage or a suitable smart electricity tariff may help you manage your energy costs outside daylight hours.
It is also worth considering your longer-term plans. If you expect to drive more miles, replace a petrol or diesel vehicle with an EV, or increase your household electricity consumption, these changes may influence the solar system size that makes sense for your property.
The best approach is to assess your household and vehicle electricity requirements together. Solar panels can help reduce your reliance on grid electricity, but a realistic assessment of generation, consumption, charging habits and tariffs is essential when estimating potential savings.
Interested in Installing Solar PV on Your Home?
If you live in Essex, Kent, Suffolk, Hertfordshire or the wider South East and East Anglia, we can assess whether your home is suitable for solar, determine what size system could be installed and, most importantly, calculate how much you could save with solar.
Contact SolarTherm UK today for a free, no obligation quote and design, tailored to your property, usage and future energy needs. No hard sell, just honest, expert advice – and the time you need to make an informed decision.
Your home. Your energy. Your future.
Frequently Asked Questions
Yes. Solar panels can generate electricity that can be used to charge an electric car at home. The amount of charging supplied by solar will depend on system size, vehicle consumption, weather conditions and when the car is connected.
The number depends on your annual mileage, your vehicle’s electricity consumption, household demand and available roof space. Your installer should assess your combined household and EV electricity requirements before recommending a system size.
It can be, particularly when you can use a significant proportion of your solar generation directly. The financial benefit depends on installation costs, imported electricity prices, export payments and your charging habits. Comparing solar charging with available smart electricity tariffs can help establish the most economical approach.
No. You can charge an EV directly using available solar generation without a home battery. Battery storage may help you use surplus electricity later in the day, but whether it is worth the additional investment depends on your household demand and charging routine.
Possibly. An EV increases household electricity demand, so expanding an existing solar system may be worthwhile if you have suitable roof space and the installation can accommodate additional panels. Assess your current generation, inverter capacity, available export arrangements and likely charging demand before deciding.
Yes. Your panels can still supply household electricity while your car is away. You could also consider battery storage for later household use or a suitable smart electricity tariff for overnight EV charging. The best approach depends on your energy consumption and charging arrangements.
Not necessarily. Battery capacity should be based on your surplus solar generation, household electricity demand and intended use. A larger battery may cost more without delivering proportionately greater savings if there is insufficient surplus generation to charge it regularly.
Planning solar around an anticipated EV purchase can help you choose a system that accommodates future electricity demand. You do not necessarily need to buy both at the same time, but your expected mileage, charging routine and future energy requirements are worth considering when designing the installation.
