Electric vehicles (EVs) are gaining ground as a viable transportation option in many nations. However, the lack of charging sites prevents EVs from gaining extensive market penetration. More and more public charging stations for EVs are being constructed as its usage increases. But if charged using the current system based on fossil fuels, EVs will have a detrimental impact on both the distribution network and the environment.

Powering vehicles with renewable energy (RE) sources like solar photovoltaic (PV) panels and wind turbines would be a huge step forward. It would also stand as a symbol of long-term progress toward an eco-friendly society. The electrical production of such charging stations may be less than the required power or very high, depending on the availability of various sources of energy (such as solar radiation and wind speed) and mechanism to store them.

Can RE be used directly to charge EVs?

In order to power most household appliances and machinery, energy produced from RE sources must first be transformed from direct current (DC) to alternating current (AC). That's also applicable if RE is used to power an EV. Most EVs and charging infrastructure are designed to use AC. Therefore, the DC electricity generated by renewable sources needs to be converted to AC using devices like inverters. Another difficulty with RE is that it produces low output voltage, which limits its utility in high-voltage applications that need an inverter. As a result, an isolated power converter placed outside the vehicle is required to increase the voltage level and deliver DC power to charge the EV battery at a respectable rate. In order to create regulated DC voltage, modern DC-based rapid chargers need two electronic conversion stages: rectification with power factor correction (PFC) and a DC/DC converter.

Types of charging facilities

Depending on the availability of RE, a charging facility can be either hybrid (using both solar and wind power) or non-hybrid connected to an adequate storage capacity. The type of charging used is the primary factor in determining the power generator's size (fast, medium or slow). The recent emerging smart technologies such as smart grids, smart metering and communication frameworks innovations will hasten the development of smart charging options that make advantage of RE. The charging facilities can be divided into three major categories based on their locations:

Home charging

Charging at home may be done at either public or private charging stations located in neighborhoods. A convenient charging option at home might be a selling point for EV buyers. More home charging infrastructure may boost EV uptake, particularly in urban areas. Therefore, increasing the amount of solar-powered charging stations in residential areas has the potential to reduce grid dependence, boost the rate of EV adoption and increase RE usage.

Office charging

Businesses are starting to provide workplace charging stations for EVs as a way to show their support for environmentally friendly practices. Because of the longer parking duration, 15% to 25% of all charging events take place at the office, making it the second most common venue for recharging EVs after the employee's home. Some businesses provide charging for RE sources at the office, and those that do often charge very little or none at all (e.g., Google and DirectTV). Also, vehicle-to-grid (V2G) technology allows the parked cars to contribute to the power grid as a distributed resource. With this synergy, renewable power may be used effectively. Similarly, RE can be integrated into the grid or a neighboring microgrid to smooth out the power fluctuations inherent to these sources.

Public charging

The public charging (PC) infrastructure consists of publicly accessible charging stations for EVs. They are preferable to residential areas for installing renewable energy infrastructure as there are a number of challenges associated with the deployment of RE facilities in residential areas. For example, there is a lack of parking, architectural constraints (such as insufficient room for solar panels) and governance concerns (e.g., wind farms are, as a rule, sparse outside of cities).

How smart charging aids EV owners opting for RE charging stations

Smart charging refers to the intelligent and data-driven management of the EV charging process, closely integrating RE sources into the equation. It uses advanced technologies, real-time communication and data analytics to optimize when, where and how EVs are charged. By analyzing factors such as RE availability, grid demand, electricity pricing and EV driver preferences, smart charging systems ensure that EVs are charged using clean and sustainable energy whenever possible. This not only reduces the carbon footprint associated with EV charging but also supports the stability of the electrical grid by strategically managing the influx of energy during peak hours. Smart charging enables EV owners to take full advantage of RE resources, aligns charging with the needs of the grid and contributes to a more environmentally conscious and efficient transportation ecosystem.

Conclusion

More charging stations are needed to meet the growing demand for EVs, which in turn makes the integration of RE sources essential for achieving long-term sustainability goals. Smart EV charging using these energy sources is vital if EVs are to realize their full potential as green transportation. EV owners can decrease the operational cost of charging during the day when there is plentiful solar irradiation or at night when there is surplus wind energy.