Off-grid solar systems cost $45,000-$65,000 on average, more than double the cost of traditional grid-tied systems, with prices varying based on system size, type, and components like backup generators or wind turbines. . This guide breaks down the real costs of building an off-grid solar system in 2025—and shows you how to make smart space-saving choices while you're at it. What Is an Off-Grid Solar System? What Affects the Cost of an Off-Grid Solar System? 1. Your location. . Becuase different area, the electricity bill is different. So the system can be paid back in 2 year roughly. This means no monthly utility bills, no blackout concerns, and full control over your energy supply.