Quick Answer
Excess energy from a hybrid solar setup is typically fed back into the grid, credited to the homeowner's utility account, or stored in a battery bank for later use.
Storing Excess Energy in a Battery Bank
In a hybrid solar system, a battery bank is used to store excess energy for later use. This is especially useful for critical loads such as refrigeration, medical equipment, and communication systems. A 48V or 24V battery bank is commonly used, consisting of deep cycle batteries with a capacity of 12-24 kWh or more. For example, a 24V, 20kWh battery bank can store enough energy to power a refrigerator for 24 hours.
Islanding and Grid Tie Operations
When the grid is present, the hybrid solar system operates in grid-tie mode, feeding excess energy back into the grid and receiving a credit from the utility company. However, in the event of a grid outage, the system can switch to islanding mode, operating independently on stored energy. This is achieved through a transfer switch, which automatically disconnects from the grid and connects to the battery bank. Islanding mode allows critical loads to continue operating, ensuring a stable power supply.
Battery Management and Grid Tie Inverters
Battery management systems (BMS) are used to monitor and control the battery bank, ensuring safe and efficient operation. A grid tie inverter (GTI) is used to convert DC power from the solar panels and battery bank to AC power, which is then fed into the grid. When excess energy is stored, the GTI can also charge the battery bank, ensuring that the system is always ready to provide power to critical loads. A high-quality GTI is essential for a smooth and efficient grid tie operation.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.