How Charging Your EV at Home Works with Solar

Thinking about an electric vehicle (EV) or already driving one? Worried about the cost of charging or how to charge during a power cut? Home solar is probably your best option to get clean, sustainable, and affordable energy to charge your EV. In this post, we'll show you how simple it is to charge your EV with solar energy, day or night, with integrated home battery storage.¹

What Happens When You Plug In During the Day? 

During daylight hours, your rooftop solar panels convert sunlight into direct current (DC) power, which an inverter then changes to alternating current (AC) for your home and EV charger. This means that when you charge your EV during the day, it runs on solar energy, reducing reliance on the grid and benefiting the environment.

Economically, solar panels provide strong solar production in many places across the UK, often covering daily EV charging needs and lowering your energy bills. In areas with schemes like the Smart Export Guarantee (SEG), you can also earn money for excess power sent back into the grid.²

How much solar power does it take to charge an EV? Let's do some maths. A single solar panel is rated at about 425W, and a typical home might have 12 panels, for a maximum power output of around 5kWp. Taking a new Tesla EV with a 60kWh to 75kWh battery as an example, it would take at least 12 hours for a full charge in ideal conditions.³ That's a clean and cost-effective way to fuel your vehicle and achieve energy independence. 

What If You Charge at Night or on Cloudy Days? 

The sun isn't always shining and the weather can be unpredictable. To charge your EV with solar power at night or on dark and cloudy days, you can use a home battery system that stores any excess power generated by your solar panels in its high-capacity battery. 

This stored energy serves as your backup power, so you can charge your EV at night, in the morning, or even when it's cloudy. The battery storage powers your home and your EV charger, ensuring smooth charging throughout the year. 

This setup works great if you work 9-to-5 and charge your vehicle in the evening. Your EV can use clean power from your home battery system instead of costly peak-hour grid electricity. This provides convenience and saves money, whatever your particular driving needs. 

How a Home Energy Management System Makes Solar Charging Smarter 

A home battery system determines how much power your solar panels are producing and how much power your home is using, and then, using grid pricing data, balances grid and solar for optimal cost savings. Any unused solar energy is stored for overnight use or low-sunlight periods so you can charge your vehicle conveniently, regardless of sunlight availability.⁴

Consider these everyday situations:

1. Everyday commuting: You're out during the day, so you charge at night. When you get home, you plug in your EV. Even though the sun is not out, your home battery, charged from the day's sun, passes that stored-up charge to your vehicle. You get to charge your car with clean energy and avoid the peak-rate electricity pricing in the mornings and evenings.
2. Rainy days: Even if it rains or cloudy weather blocks out the sun, your home battery system continues to deliver power for uninterrupted EV charging. The system uses this stored solar energy before tapping into the grid.
    

This intelligent management provides energy independence and reliability for your home and car. It helps you save money and reduce your carbon footprint by minimising grid electricity use, especially during peak times. An adaptable and integrated system is key. One example is how the Powerwall adapts to your energy needs, which makes it possible to do your Tesla vehicle charging during a power cut, giving you added peace of mind.

Can I Prioritise My EV for Solar Charging? 

Here's where the power of an integrated energy ecosystem comes into play: it's all centrally controlled. An app can let you monitor your energy setup and set charging preferences and schedules for your EV right from your phone. 

An integrated app allows you to synchronise EV charging with solar production hours, so you can prioritise charging with excess solar energy from your battery storage. The Tesla app, for example, has a Charge on Solar option that directs surplus solar power to your EV or prioritises Powerwall based on your system setup. 

You can also set backup priorities to reserve energy in your battery storage for home use. This granular control helps maximise your solar energy usage, reducing reliance on the grid and saving you money. Ideally, the system integrates into your daily life, ensuring your EV is always ready, powered by your clean energy. 

Hardware & Setup: What You’ll Need 

To set up a solar-powered EV charging system, you’ll need a few key pieces of equipment designed to work together: 

1. Solar panels: These are your primary energy makers, turning sunlight into electricity. 
2. Inverter: Converts the DC power produced by the solar panels and turns it into usable AC power for your home and EV. The inverter can be a separate item, or integrated with the battery storage, like the Powerwall 3. The inverter must be as efficient as possible and connect smoothly with the rest of the system. 
3. Home battery: Stores extra solar energy for nighttime use, on cloudy days, or as backup. Typically, a standalone part of the overall home battery system, but can also include the inverter, as noted above. 
4. EV charger: The home charging station provides fast and efficient charging. Some models have Wi-Fi for updates and app integration for monitoring and scheduling. The EV charger should be built for indoor and outdoor use. 
    

With so many parts needing to work together, smooth integration, with all components engineered to work together, is the priority.⁵ Professional installers will assess your home's needs and local rules to design and install a system tailored to your needs, ensuring optimal performance and safety. As of April 2022, the UK also has a 0% VAT rate on the installation of solar panels, making the process even more affordable.⁶

What the Everyday Experience Feels Like 

Effortless; that's how simple and intuitive a high-quality energy system feels day-to-day. Plugging in your EV feels like plugging in any other charger, but behind the scenes, there's a smart system at work.

Connect your EV to the charger, and the system takes over automatically, balancing energy flows between your home's needs, solar production, and EV charging. The system always uses the most efficient and cost-effective source, whether solar, battery storage, or grid, without any extra effort on your part.

This automation provides convenience and control. The real-time energy dashboard in the app lets you know what's going on at any moment, right from your phone. The app includes the following information:

1. Live Energy Flow: Get a detailed look at real-time energy flow in the system. You can see where energy is coming from: the solar panels, the battery, or the grid.
2. Battery Status: Monitor the remaining charge in your battery backup, including the amount of energy it's providing or whether it's charging from solar panels or the grid. 
3. Charging Statistics: These statistics give a detailed overview of which source your EV is charging from. This could help you optimise your energy use and identify when it is most cost-effective to charge your EV.
4. Historical Data: Look back at trends to identify patterns in energy usage and make informed adjustments to your settings for better efficiency and cost savings.
    

This transparency empowers you to actively manage your home's energy. This makes day-to-day sustainability management easy: your car is always ready to go, charged by your own clean energy, with complete visibility into your energy footprint. 

The Tesla Energy Advantage 

Tesla stands out in home solar energy and EV charging by integrating solar generation, energy storage, and EV charging into one cohesive system with solar panels, Powerwall, and Tesla charger. Tying it all together is the Tesla app, which gives you a single, easy-to-use way to control and monitor everything in the Tesla energy system. This simplicity makes installation and daily use straightforward, ensuring all components work together perfectly. 

With our focus on innovation and global reach, we offer smart energy management so homeowners can easily benefit from our energy solutions. Choosing Tesla means investing in a future powered by clean energy for both your home and car. This choice offers energy independence and significant long-term savings while supporting a more sustainable planet. 

Ready to take control of your energy future? Request a Powerwall quote today and discover how easy it is to store clean, reliable energy.