Experiencing frequent power outages in Puerto Rico, the author, with a computer science background and no formal electrical engineering training, details how to build a home solar backup system for under $5,000. This necessity arose from the island's fragile power grid, exacerbated by aging infrastructure and high electricity costs, with outages becoming a critical issue during and after Hurricane Maria in 2017.

The system comprises essential components: solar panels, copper wire, an inverter, transfer switches, batteries, and fuses. Optional enhancements include bus bars, battery monitors, wire conduits, and a battery disconnect switch. Understanding energy needs involves calculating daily usage (e.g., 10-20 kWh for low, 20-35 kWh for medium, 35+ kWh for high) and then sizing the system based on daily sun hours and desired output.

For example, to generate 10 kWh per day with 7 sun hours, one would need approximately 1.43 KW per hour, plus extra capacity for cloudy days. When choosing solar panels, considering the cost per watt is crucial, with used panels offering significant savings at around $0.20/watt compared to new ones at $0.60-$0.80/watt. The author emphasizes that this guide is for informational purposes, and consulting a qualified electrician is paramount before undertaking any electrical work.