The number of gel batteries needed for a 10kW off-grid solar system depends on several factors, including the battery capacity, the desired depth of discharge, and the system’s voltage.
Here’s a general approach to estimate the number of gel batteries required:
1. **Calculate Energy Storage Capacity:** Determine the amount of energy storage required to support your system. This depends on factors such as your daily energy consumption, desired autonomy (number of days without sunlight), and depth of discharge (DoD). For example, if your daily energy consumption is 50 kWh and you want three days of autonomy with a 50% DoD, you would need 50 kWh/day * 3 days * 1.5 (to account for DoD) = 225 kWh of storage capacity.
2. **Select Battery Capacity:** Gel batteries typically have a rated capacity in ampere-hours (Ah) or kilowatt-hours (kWh). Divide the required energy storage capacity by the battery’s capacity to determine the number of batteries needed. For example, if each gel battery has a capacity of 10 kWh, you would need 225 kWh / 10 kWh per battery = 22.5 batteries.
3. **Account for System Voltage:** Consider the system’s voltage when determining the number of batteries in series and parallel connections. Gel batteries are usually connected in series to achieve the desired system voltage and in parallel to increase the storage capacity. Ensure that the total voltage matches your system requirements.
4. **Round Up:** Since you cannot have a fraction of a battery, round up to the nearest whole number to determine the final number of gel batteries needed. In this example, you would likely need 23 gel batteries.
It’s essential to consult with a solar energy system installer or engineer to ensure accurate sizing and proper configuration of the battery bank for your specific off-grid solar system requirements. They can consider additional factors such as temperature compensation, maintenance requirements, and safety considerations.