Background: South Africa is facing a severe power crisis, with Eskom implementing rolling blackouts (Load Shedding), resulting in power outages lasting 6–10 hours per day.

User Profile: A middle-class household with an existing 5kW PV system, equipped with an aquarium heater, two refrigerators, and a security system.

Pain Point: Frequent power outages cause the aquarium heater to fail (resulting in fish deaths), food in the refrigerators to spoil, and the security system to become inoperative.

Solution:

• 1、Configuration: 10kWh residential energy storage + 5kW hybrid inverter + Automatic Transfer Switch (ATS)

• 2、Strategy: Perform peak shaving and valley filling during normal conditions to reduce electricity costs. During a power outage, automatically switch to off-grid mode, prioritizing power supply to the aquarium, refrigerators, security system, and lighting.

Results:

• 1、Essential equipment continues to operate during outages, significantly improving fish fry survival rates

• 2、Food in refrigerators no longer spoils, saving approximately ZAR 3,000 annually in prevented food waste

• 3、Payback period of approximately 4 years (combining peak-valley arbitrage with savings from prevented outage losses)