Is Charge Scheduling A Good Idea For Off-Grid Solar Systems?

Understanding the Benefits of Charge Scheduling

Charge scheduling is a strategy that involves coordinating the charging of electric vehicles (EVs) with available renewable energy sources, such as off-grid solar systems. This approach can greatly benefit off-grid solar systems by reducing the strain on the battery bank and increasing its lifespan. By scheduling EV charging during periods of high solar production, you can minimize the need for grid-tied or generator backup power, resulting in significant cost savings.

Implementing Charge Scheduling Techniques

To implement charge scheduling effectively, you’ll need to monitor your solar production, energy usage, and battery state of charge in real-time. This data can be collected using a combination of on-site monitoring equipment and cloud-based software. Once you have access to this information, you can set up a scheduling system to automatically adjust EV charging times based on available solar energy. For example, you can set your EV charger to charge at a lower power level (e.g., 7.2 kW) during periods of high solar production, and then switch to a higher power level (e.g., 11.5 kW) when solar production dips.

Real-World Examples and Best Practices

In a typical off-grid solar system, a 5kW solar array can produce around 25 kWh of energy per day, assuming 5 peak sun hours. By scheduling EV charging during periods of high solar production, you can recover up to 80% of the energy used by the EV. To achieve this, aim to schedule EV charging between 10 am and 3 pm, when solar production is typically highest. Additionally, consider implementing a “charge ahead” strategy, where excess energy is stored in the battery bank during periods of high solar production, and then used to charge the EV when needed. This approach can help optimize energy usage, reduce waste, and increase the overall efficiency of your off-grid solar system.