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EV charger
21 Oct 2020

EV chargers and Solar PV

By Lynn
  • Read time: 3 minutes
Electric cars reduce your carbon footprint, save you on fuel costs and now, you can charge your car with solar energy. This excellent idea is achieved by combining EV stations with solar PV systems. Just like home appliances are fired up with solar energy, some EV chargers are solar responsive and will omit the need to draw electricity from the primary grid in your home. Read on to learn more about how EV chargers and Solar PV can work together.

How do Solar PV and EV charging systems work?

Solar PV systems convert radiation from the sun into electricity. To do so, it utilises solar cells that consist of two layers of semi-conductors, usually made of silicon. Atoms in the silicon are vibrated by the sunlight to produce flowing electrons that create direct current (DC). Cables consequently carry the current to an inverter, which turns them into alternating current (AC), which is passed and used in your property’s distribution grid as electricity.

From there, a charging point such as the myenergi zappi will be installed and connected to the solar PV system using a clever adaptor named the myenergi Hub, this allows the zappi to draw electricity from your solar system and charge your vehicle with 100% renewable power.


How much power will you need to charge your EV?

The amount of power needed is determined by the overall battery capacity of your EV. Electric vehicle battery capacity is measured in kilowatts per hour (kWh). For instance, the Tesla Model S has a 100kWh battery while the BMW i3 has a 33kWh battery. This means that Tesla won’t need as frequent charging as the BMW would. However, the Tesla will need much more energy to charge than the BMW. This means that if your electric car has a large capacity battery, you will need to use more power. If the solar PV system is not generating enough kWh then some electricity may be taken from the grid, this is otherwise known as load balancing. Tesla Powerwall is extremely useful in these situations as it can store electricity generated by Solar PV to be used at a later time, reducing your reliance on the grid.

Een elektrische auto verbruikt momenteel ongeveer 15 kWh aan stroom per 100 kilometer en de gemiddelde autorijder rijdt 15.000 kilometer per jaar. In totaal verbruikt een elektrische auto dus ongeveer 2.250 kWh per jaar. Betaal je dit via je elektriciteitsnet thuis? Dan kost dit je €517,50 per jaar. Gezien je omgerekend een besparing van €400 per jaar realiseert met je zonnepanelen kost het rijden van je auto in feite dus €117,50 per jaar. 

Rijd je 15.000 kilometer per jaar op benzine? Dan kost je dit ongeveer €1.450 per jaar uitgaande van een gemiddelde verbruik van 1 op 17 en een literprijs van €1,65. Van één jaar benzine rijden kan je daarmee een laadpaal aanschaffen om vervolgens ruim €1.300 per jaar te besparen.

How many panels will you need to provide enough power for charging your EV?

How Many Panels Will You Need To Provide Enough Power For Charging Your EV?

You will need three key points to determine the number of solar panels required to charge your EV efficiently. These include:

  • The amount of electricity your EV will use annually

  • The wattage of solar panels you wish to install

  • Environmental factors in your area

Assuming you are an average UK driver, a standard electric vehicle will need 4,000 kWh of annual electricity. This means that if you want to install standard solar panels which provide 320 to 330 watts, you would require 7 to 9 solar panels depending on their locations.

This calculation is based on averages, which means that if you want solar panels that produce more watts than standard ones or you drive less than an average driver, the number of panels you need will be lower. Also, the number of panels required will increase if you go for low wattage products, drive more, or have more than one electric car in your home.

Solar energy

Think about the future

Even if you plan to combine solar energy and an EV charge point, it would be in your best interest to think about the future. You may create a plan that will allow for future changes. For instance, If you are planning to buy another electric car in future, you want to plan your project in an add-on friendly way. Some of the best methods include:

Installing an Inverter with the Capability to Handle More Power

The default option for inverters that will handle increased power is the string inverter. With this device, multiple solar panels are connected in such a way that they can feed all their energy into a single inverter without overpowering it. As such, you should ask your installer to use an inverter that can handle more solar panels than the number you are currently installing.

Install a Micro-inverter

This device is installed on each solar panel. With a micro-inverter, you may add as many solar panels as you like without having to worry whether the existing inverter can handle the additional power that the new panels will generate.

Install another Solar System

This option is ideal when you need to add a new charging system in your home without affecting your current one. You can also use the solar system for operating home appliances when not charging your EV. Solar PV also offers a secondary income via exporting your excess electricity, currently the best export rates available are limited to Tesla customers via the Tesla energy plan.


Solar energy is a cost-effective and an environmental-friendly way of charging your electric vehicle. This energy efficient method relies on standard solar panels and requires devices that are compatible with solar energy such as the myenergi zappi. Installing renewable technology such as solar panels and smart EV chargers are usually eligible for tax deductions and government grants, which are available if government and OLEV guidelines are followed.

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Written by Lynn

Writes blogs about EV charging and climate solutions for 50five.