Solar compatible EV charger explained

Charging your electric vehicle (EV) using electricity generated by your home solar panels can significantly cut costs and boost your energy independence. This guide explains how solar-compatible EV chargers work, the benefits for UK homeowners, and what to consider when choosing and installing a system. It's about taking control of your energy, turning your home into a personal power station.

What is a solar compatible EV charger?

A solar-compatible EV charger is a smart device designed to work in harmony with your home solar photovoltaic (PV) system. Unlike standard EV chargers that simply draw power from the grid, these intelligent chargers prioritise using the electricity generated by your solar panels. This means you can power your car with free, clean energy directly from the sun, reducing your reliance on grid electricity and its fluctuating costs.

How energy diversion works

The core technology behind Solar EV chargers is energy diversion. These chargers typically employ a current transformer (CT) clamp that monitors your home's electricity generation from solar panels and its overall consumption in real-time. When your solar panels produce more electricity than your home is currently using, this "surplus" energy would ordinarily be exported back to the grid, often for a modest payment through the Smart Export Guarantee (SEG).

Instead, a solar-compatible charger intelligently redirects this surplus energy to your EV's battery. This maximises your self-consumption of renewable energy, ensuring that the electricity you generate is used efficiently within your home before any is exported. This process is dynamic, constantly adjusting the power flow to match available solar generation and your home's demand.

The role of smart technology

Smart technology is crucial for the efficient operation of Solar EV chargers. These chargers integrate with your home energy system, often via a dedicated app, allowing you to monitor solar generation, home consumption, and EV charging status. This connectivity enables features like:

• Optimised charging modes: Prioritising solar surplus, setting charging schedules, or using a blend of solar and grid electricity.
• Remote control: Starting, stopping, or pausing charging from your smartphone.
• Data insights: Tracking your energy usage and savings over time.

Benefits of Solar EV charging for UK homes

For UK homeowners with solar panels, integrating a solar-compatible EV charger offers several compelling advantages, transforming your home into a more energy-independent and cost-effective hub.

Significant cost savings on charging

Using your own solar energy to charge your EV drastically reduces your electricity bills. Instead of paying for grid electricity, you're using power generated for free on your roof. This can lead to substantial savings over the lifespan of your EV, especially given that the average UK home uses around 2,700 kWh of electricity per year1. By offsetting a significant portion of your EV charging costs, your overall household energy expenditure can decrease considerably.

Enhanced energy independence and self-sufficiency

Solar EV charging is a strategic move towards greater energy independence. It shifts the balance of energy control into your hands, reducing your reliance on external energy suppliers and fluctuating market prices. By generating and consuming your own electricity, you become less vulnerable to grid outages and price hikes, embodying a true "power play" in managing your home's energy needs.

Environmental advantages and reduced carbon footprint

Charging your EV with solar power means you're fuelling your transport with 100% clean, renewable energy. This significantly lowers your carbon footprint, contributing to a healthier planet and a more sustainable future. It's a tangible way to make an environmental difference directly from your home.

Key features to look for in a Solar EV charger

When selecting a Solar EV charger, consider features that enhance efficiency, safety, and user experience.

Smart charging modes and app control

Look for chargers offering multiple smart charging modes. These might include a "solar-only" mode that exclusively uses surplus solar power, a "fast charge" mode that blends solar and grid electricity for quicker charging, or programmable schedules to charge during off-peak hours. Comprehensive app control allows for easy management, monitoring, and customisation of your charging preferences.

Dynamic load balancing for home safety

Dynamic load balancing is a critical safety feature. EV charging demands significant power, and without proper management, it can overload your home's electrical supply. Dynamic load balancing monitors your home's real-time electricity consumption and adjusts the EV charging rate accordingly, preventing overloads and ensuring your household appliances continue to operate without interruption. This feature is particularly important for homes with multiple high-power appliances.

Compatibility with solar PV systems and batteries

Ensure the charger is compatible with your existing solar PV inverter and any home battery storage system you might have or plan to install. Seamless integration allows for optimised energy flow, prioritising battery storage or EV charging based on your preferences and energy tariffs. Some chargers are designed as part of a wider home energy management ecosystem.

Power output and charging speed

Chargers typically come in various power outputs, with 7.4 kW being a common output for single-phase UK homes. Consider your daily driving needs and how quickly you need your EV to charge. While higher power outputs are available, they may require three-phase electricity, which is less common in residential UK properties.

Choosing the best Solar EV charger for your home

Selecting the right Solar EV charger involves assessing your specific energy situation and understanding the market.

Assessing your energy needs and solar setup

Before choosing a charger, evaluate your current solar PV system's capacity and your typical daily solar generation. Consider your EV's battery size and your average daily mileage to determine your charging requirements. This assessment will help you choose a charger that can effectively meet your needs using your available solar surplus.

Popular Solar EV charger brands in the UK

The UK market offers several reputable Solar EV charger brands. Some popular choices include Myenergi Zappi, Ohme Home Pro, and BG Sync EV. Each brand offers a unique set of features, app functionalities, and integration capabilities. Researching user reviews and professional comparisons can help you narrow down options based on your priorities.

Understanding warranties and customer support

A good warranty provides peace of mind. Check the warranty period for both the charger unit and its installation. Reliable customer support is also essential for any technical queries or issues that may arise. Look for brands with a strong reputation for after-sales service.

Installation and UK grants for EV chargers

Professional installation is key to ensuring your Solar EV charger operates safely and efficiently. Understanding available grants can also significantly reduce upfront costs.

The professional installation process

Installing an EV charger is a job for a qualified electrician. They will assess your home's electrical system, ensure it can safely handle the charging load, and connect the charger to your solar PV system. The installation must comply with IET Wiring Regulations (BS 7671) and relevant building regulations. A certified installer will also configure the smart features and ensure seamless integration with your home energy setup. For more information on setting up your home for EV charging, you can read our guide on EV charging at home.

Navigating the electric vehicle chargepoint grant (OZEV grant)

The UK government offers specific Electric Vehicle Chargepoint Grants to help reduce the cost of installing an EV chargepoint. However, it's important to note that owner-occupiers of houses with private off-street parking are generally not eligible for these domestic grants. Instead, the grants are primarily available for:

• The EV chargepoint grant for renters and flat owners: This provides up to £500 towards installation for those who own and live in a flat, or rent any residential property, provided they have private off-street parking.
• The EV chargepoint grant for households with on-street parking: This offers up to £500 for households installing a cross-pavement solution, such as a charging gully, where they only have on-street parking.

For domestic installations, the customer applies directly via gov.UK to determine their eligibility and secure the grant. The installer's role begins after the application is approved.

Other potential incentives and considerations

Beyond the OZEV grant, consider the SEG, which allows you to receive payments for any surplus renewable electricity you export to the grid. While Solar EV charging aims to maximise self-consumption, the SEG provides a financial benefit for any unavoidable exports. Some energy suppliers offer time-of-use tariffs that provide cheaper electricity rates during off-peak hours. While specific 'EV tariffs' have been withdrawn from sale, these general time-of-use tariffs can still be beneficial for charging when solar generation is low. Understanding your smart meter installation can help you take advantage of these tariffs.

Maximising your Solar EV charging efficiency

To get the most out of your Solar EV charging setup, consider these strategies.

Optimising charging schedules

Use your charger's smart features or your home energy management system to schedule charging during periods of peak solar generation. If your solar panels are producing more electricity than your home needs, charging your EV at that time ensures you're using free, clean energy. Conversely, if solar generation is low, consider charging during off-peak grid electricity hours if you are on a time-of-use tariff.

Integrating with home energy management systems

A holistic approach to home energy management can further enhance efficiency. Integrating your Solar EV charger with a broader home energy management system allows for intelligent decision-making across all your energy-consuming devices. For example, the Fuse app allows you to connect your EV and monitor its state of charge, alongside your meter readings, helping you understand your energy usage.

Future-proofing your charging setup

Technology evolves rapidly. When choosing a charger, consider its ability to receive over-the-air software updates, ensuring it remains compatible with future grid services and smart home technologies. Features like vehicle-to-grid (V2G) or vehicle-to-home (V2H) capabilities, while not widely available yet, represent future opportunities for EVs to become active participants in home energy management.

Conclusion and future outlook

Solar compatible EV chargers offer a powerful way for UK homeowners to take control of their energy use, reduce costs, and contribute to a sustainable future. By intelligently diverting solar surplus to your EV, you transform your home into a hub of energy independence. As technology advances and integration with home energy management systems becomes more sophisticated, the benefits of Solar EV charging will only continue to grow, empowering homeowners to make strategic "power plays" in their energy consumption.

References

1. UK Government. Subnational electricity and gas consumption summary report 2021