EV charging and solar energy integration

For many electric vehicle users, their contribution to the environment through the use of clean energy is significant. The use of solar energy fits well with these intentions. Solar energy produces no carbon dioxide emissions, helping to reduce the impact on the environment.

Besides this, using solar energy allows you to save money. The solar power plant itself reduces energy costs. Additional savings arise when, instead of sending energy into the grid at low rates, you use it to charge an electric vehicle.

EV charging using solar panels is an efficient and environmentally friendly way to generate energy, as well as provide additional convenience and improve life quality. This is a quite complex home system that includes the following key components:

• Solar panels are an energy source that converts light energy from the sun into electrical energy.
• An inverter is a device that converts electricity collected by solar panels into alternating current for further use in the household, for distribution to the network, or for charging a car.
• A charging station that regulates the charging current and ensures compatibility of the electric vehicle parameters with the power supply network.
• A control system is a set of devices that provide protection, and interaction with the user, redirecting energy flows in the right directions by algorithms depending on the user’s wishes.

In general, the scheme of generation, distribution, and consumption of energy looks as shown in the figure above.

To perform calculations and answer the question of what equipment should be used, and whether it will be compatible with other devices, which are already available at the site, you need a little research. You can do this yourself or contact an expert who will tell you how to do it better, more efficiently, and without extra costs.

First of all, you need to understand whether the energy generated by solar panels is enough to cover not only your home demand but also to charge your car. The following points have to be taken into consideration:

• Electric vehicle specifications
• The average distance an electric car travels during the day, as well as driving style, which greatly influences energy consumption
• Average and peak home energy consumption
• Solar power plant generation possibilities

Here we are talking about solar power plants that are capable of supplying electricity to the general grid. If an autonomous solar power plant is used, the scheme is simplified. However such solutions are not very popular due to reduced reliability in terms of uninterrupted generation.

Also not very common (perhaps yet) are solutions using energy storage devices due to their high cost.

In the case of a network solar station and an adaptable charging station, three main charging modes can be distinguished. Each offers unique benefits for different situations.

Solar-only charging mode. Following its name, in this profile the charging process is initiated exclusively using green energy. The minimum required generation value after conversion in the inverter is 6 Amps (standard for charging station manufacturers). If more than 6A is generated by the solar panels at any point, then the charging current becomes higher. If it exceeds the maximum charging current, then the excess energy is used to charge the home or is returned to the grid. If the generation produces less than 6A, the charger will remain in standby mode.

Combined charging mode with priority for solar panels. In this profile, the charging process takes place using a combination of solar and grid energy. The user sets the minimum current value from the solar station at which charging begins. If the set value is less than 6 A, the difference in current will be supplemented by the network power.

Let's say we set the solar generation threshold to 1A. In this case: