Solar Panels & Electric Cars: The Ultimate Guide To Sustainable Driving
Solar energy and electric vehicles (EVs) have emerged as two powerful technologies that, when combined, represent clean transportation. As electric cars become increasingly accessible through schemes like The Electric Car Scheme's salary sacrifice, many drivers are now looking to solar power as the next step in their sustainable journey.
This guide explores two exciting approaches to solar-powered driving: vehicles with built-in solar panels and home solar systems designed for EV charging. We'll look at how these technologies work, their practical benefits in UK conditions, and how they can significantly reduce both your carbon footprint and running costs.
Key Insights:
Solar charging can reduce EV running costs by up to 40% compared to standard grid charging in the UK, with the average home solar system paying for itself in 7-10 years,
A typical UK home solar system (3.5kW) can fully charge a midsize EV like the Kia e-Niro in one day during summer months, providing around 180 miles of range,
Some newer EVs now include integrated solar panels that can add up to 25 miles of range per week in typical UK conditions, extending battery life and reducing charging needs,
Combining The Electric Car Scheme's salary sacrifice with solar charging creates a double-saving effect, making sustainable transport significantly more affordable for UK drivers.
Electric Vehicles with Integrated Solar Panels
One of the most exciting developments in EV technology is the integration of solar panels directly into the vehicle's design. Several manufacturers are now offering production or near-production models with this capability:
Fisker Ocean
The Fisker Ocean SUV features a solar roof called "SolarSky" that can generate up to 1,500 miles of additional range annually in optimal conditions - particularly if you’re in California. In typical UK weather, owners might expect around 1,000 extra miles per year – equivalent to about 20 miles per week of free driving.
Sono Sion
Originally the Sono Sion was known as a compact car, which took solar integration to the next level with panels covering much of its exterior. Now, the Sono Sion focuses on buses, trucks and vans.
Lightyear 0 & 2
The Lightyear 0, though limited in production, pioneered efficient solar integration with the ability to add up to 43 miles of range daily in perfect conditions. Its successor, the more affordable Lightyear 2, promises to bring this technology to a broader market by 2025.
Toyota Prius PHEV (with Solar Roof Option)
The Prius plug-in hybrid offers a solar roof option that can add about 3 miles of driving range daily in UK conditions – modest but helpful for extending battery life and reducing charging frequency.
Reality Check: Solar Integration in UK Conditions
While these innovations are promising and rather exciting, you may be wondering whether there’s any point in having an EV with a solar panel in the UK - considering the amount of sunlight we get. Let’s have a look at the real-world performance in UK weather:
Average UK solar irradiance: This varies significantly across the country. 800-1,100 kWh/m² annually (compared to 1,600-2,200 kWh/m² in southern Europe),
Seasonal variation: December yields only about 15-20% of the solar energy of June in the UK,
Typical range extension: 2-5 miles per day in summer; 0.5-1 mile per day in winter,
Primary benefit: Supplemental charging rather than primary power source in UK climate.
While integrated solar panels won't eliminate the need for regular charging, they can reduce charging frequency, extend battery life, and provide an additional layer of energy independence – particularly valuable during summer road trips or in emergencies.
Can You Charge Your Electric Car With Solar Energy?
Yes, you can charge your EV with solar energy. To do this effectively, you'll need to install a domestic Solar Photovoltaic System (Solar PV) along with an EV charging station.
A typical UK domestic PV system generates between 1 and 4 kilowatts of power in optimal conditions. This is sufficient to fully charge an electric car with a 40kWh battery capacity (like a Nissan Leaf) in about 8-10 hours of good sunlight.
However, the amount of available energy for charging an electric car depends significantly on:
Season and weather conditions,
Size and efficiency of your solar array,
Time of day when charging occurs,
Energy consumption by other household appliances.
In winter months, when there is less daylight and more cloud cover, you'll likely need to supplement your solar PV system with power from the grid. Many UK solar EV owners find that they can meet 60-70% of their charging needs with solar during summer, but only 20-30% during winter.
How Many Solar Panels Do You Need To Charge An EV?
The number of solar panels required depends on your vehicle's battery size, your driving habits, and the efficiency of the panels you install.
Here's a practical guide for UK conditions:
Calculation Formula:
Number of panels = (Daily driving range in miles × EV efficiency in kWh/mile) ÷ (Panel wattage × daily peak sun hours × system efficiency)
| EV Model | Battery Size | Average Daily Commute | Panels Needed (370W) |
|---|---|---|---|
| Nissan Leaf | 40kWh | 30 miles | 8-10 panels |
| Tesla Model 3 | 60kWh | 30 miles | 9-11 panels |
| Kia e-Niro | 64kWh | 30 miles | 9-12 panels |
| VW ID.3 | 58kWh | 30 miles | 8-11 panels |
Based on average UK peak sun hours of 2.5-3.5 hours daily and system efficiency of 80%
For a complete system capable of meeting most of your charging needs throughout the year in the UK, a 3.5-4kW solar array (typically 10-12 panels) is generally recommended. This provides a good balance between cost and energy production.
It's always advisable to consult with a professional solar installer who can assess your specific roof orientation, angle, shading, and local weather patterns to recommend the right system size for your needs.
Can You Use A Regular EV Charger With Solar Panel Charging?
Yes, you can use a regular EV charger with solar panel charging. To integrate solar power with your EV charging setup, you'll need:
A solar PV system installed on your property,
An inverter to convert DC power from solar panels to AC power for home use,
A standard EV charging station (Level 1 or preferably Level 2).
The system works seamlessly; when your solar panels are generating electricity, that power feeds into your home's electrical system, offsetting the electricity drawn by the EV charger. Most UK installations use this setup, where solar production reduces the amount of grid electricity needed rather than directly powering the car.
Smart EV Chargers for Solar Optimisation
For maximum efficiency, consider installing a smart EV charger that can communicate with your solar system. These advanced chargers can:
Automatically adjust charging rates based on solar production,
Schedule charging during peak solar hours,
Balance power between your EV and other household demands,
Integrate with time-of-use electricity tariffs,
Provide detailed data on solar vs. grid charging percentages.
Popular UK-compatible smart chargers with solar integration features include the Zappi, Ohme, and Wallbox Pulsar Plus.
Cost Analysis: Solar Charging vs. Grid Charging
Initial Investment for Solar EV Charging
A typical solar PV system suitable for EV charging in the UK costs:
| System Size | Approximate Cost | EV Charging Capability |
|---|---|---|
| 3kW system | £4,000-£6,000 | 30-40 miles per day |
| 4kW system | £5,500-£7,500 | 40-55 miles per day |
| 6kW system | £7,500-£10,000 | 60-80 miles per day |
Optional home battery storage adds £3,000-£8,000 depending on capacity
Running Cost Comparison
| Charging Method | Cost per mile | Annual Cost (10,000 miles) |
|---|---|---|
| Grid only - standard rate | 7-9p | £700-£900 |
| Grid only - EV tariff at night | 4-6p | £400-£600 |
| Solar and grid mix - UK average | 3-5p | £300-£500 |
| Solar only - excluding system cost | 0-1p | £0-£100 |
Based on the average UK electricity price of 28p/kWh as of 2024
Payback Period and ROI
With current UK energy prices, the typical payback period for a solar PV system used for EV charging is:
Without battery storage: 7-10 years
With battery storage: 10-14 years
Over a 25-year system lifespan (the typical warranty period for solar panels), total savings can exceed £15,000-£20,000 when used for both home power and EV charging.
UK Grants and Incentives for Solar EV Charging
The UK offers several incentives that can help offset the cost of installing a solar PV system for EV charging:
Smart Export Guarantee (SEG)
Energy suppliers must pay you for the excess electricity you export to the grid. Rates vary by supplier but typically range from 4-6p per kWh, providing additional income from your solar installation.
VAT Reduction
Solar panel installations currently benefit from a reduced 0% VAT rate and is set to remain this way until the end of March 2027. After this, the rate will increase to 5%.
Local Council Grants
Some local authorities offer additional grants or rebates for renewable energy installations. Check with your council's sustainability department for available programs.
Workplace Charging Scheme
For businesses, the Workplace Charging Scheme provides up to £350 per charging socket (maximum of 40 sockets) for installing EV charging points, which can be paired with commercial solar installations.
The Advantages And Disadvantages Of Using Solar Panels To Charge Your EV
It is important to understand the advantages and disadvantages of using solar panels to charge your electric car.
Advantages of using solar panels to charge your EV
Environmental benefits: Charging your EV with solar power maximises the environmental advantages of electric driving. According to the Energy Saving Trust, a home solar PV system can save around one tonne of carbon per year.
Long-term cost savings: After the initial investment, solar charging is significantly cheaper than using grid electricity. With rising energy costs, these savings increase over time.
Energy independence: Generating your power protects against electricity price increases and supply issues.
Increased property value: Homes with solar installations typically sell for 6-7%, according to a 2024 study.
Minimal maintenance: Solar PV systems require very little maintenance while continuing to generate electricity for 25+ years.
Disadvantages Of Solar EV Charging
High initial cost: Installing a solar PV system requires a substantial upfront investment, though this is offset by long-term savings,
Weather and seasonal dependency: Solar production varies significantly between summer and winter in the UK, requiring grid supplementation during darker months,
Space requirements: You'll need sufficient roof space with the right orientation and minimal shading for effective solar production,
Charging timing mismatch: Solar panels produce electricity during daylight hours, while many EV owners prefer to charge overnight, necessitating battery storage for a complete solar charging solution,
Complex setup: Integrating solar, home energy, and EV charging systems can require professional installation and configuration.
Maximising Financial Benefits Of Solar EV Charging
To get the most from combining solar power with your electric vehicle, consider these strategies:
1. Charge during daylight hours when possible
Schedule charging during peak solar production (10 am-4 pm).
2. Consider Battery Storage
While adding cost, home batteries allow you to store excess solar energy for evening/night charging, increasing solar utilisation by 25-40%.
3. Choose The Right Electricity Tariff
Many UK suppliers offer special EVs or time-of-use tariffs with cheaper overnight rates, which can complement solar charging by providing low-cost power when solar isn't available.
4. Install An Energy Management System
Smart systems can automatically direct solar power to your EV when production exceeds home usage and switch to grid power when necessary.
5. Double Your Savings With Salary Sacrifice
Combining The Electric Car Scheme's salary sacrifice program with solar charging creates a powerful financial advantage:
Save 30-60% on the cost of leasing an EV through salary sacrifice,
Then save 40-100% on charging costs with a solar PV system,
Result: Dramatically reduced total cost of electric vehicle ownership.
Frequently asked questions
How Long Would It Take To Charge An EV Using Solar Panels?
Charging time depends on your solar system size, weather conditions, and EV battery capacity. For a 40kWh EV like a Nissan Leaf and a 4kW solar system in good UK summer conditions, expect a full charge in approximately 10-12 hours of daylight. In winter, this extends significantly due to reduced solar production.
Is Investing In Solar Charging For Your EV Worth It?
For most UK homeowners who drive electric, solar charging provides a positive return on investment over the system's lifespan. The financial case is strongest if you:
Drive regularly (7,500+ miles annually),
Have suitable roof space for solar panels,
Plan to stay in your home for 5+ years,
Can charge during daylight hours at least some of the time.
What Is The Best Time To Charge An EV With Solar Panels?
The optimal time is during peak solar production hours (typically 10 am-4 pm in the UK), especially on clear, sunny days. If you can't charge during these hours due to work commitments, a home battery system allows you to store solar energy for evening charging.
Do I Need A Special EV Charger For Solar Panel Charging?
While standard EV chargers work with solar systems, smart chargers specifically designed for solar integration offer better efficiency and features.
How Does An EV Charger Work With A Home Battery System?
A home battery stores excess solar energy produced during the day, which can then be used to charge your EV during the evening or night. The system typically includes smart controls that prioritize battery power for EV charging before drawing from the grid, maximizing your use of solar energy.
Do I Also Need A Battery To Charge An EV With Solar?
A battery isn't strictly necessary, but it significantly increases the proportion of solar energy used for charging. Without a battery, you'll need to charge your car during daylight hours or rely partially on grid power. With a properly sized battery system, you can store excess daytime solar production for evening or overnight charging.
How Do UK Seasonal Variations Affect Solar EV Charging?
The UK experiences dramatic seasonal variations in solar production. A system that can fully charge your EV in summer might only provide 20-30% of charging needs in December and January. Most UK solar EV owners rely more heavily on-grid charging during winter months.
Driving on Sunshine
The combination of solar power and electric vehicles represents the gold standard in sustainable transportation. Whether you choose an EV with integrated solar panels or pair your electric car with a home solar system, you're taking a significant step toward energy independence and environmental responsibility.
For UK drivers, the financial case for solar-powered EVs has never been stronger. Rising electricity costs, declining solar installation prices, and the significant savings available through The Electric Car Scheme's salary sacrifice scheme create a compelling opportunity to dramatically reduce both the upfront and running costs of electric driving.
Ready to combine the benefits of affordable electric car leasing with clean solar energy? Get a quote today to see how much you could save with The Electric Car Scheme.
Last updated: 28.02.25
