The cost of an off-grid solar system varies widely due to factors like battery expenses. Roughly, a 5kW system may cost between $14,000 to $17,000, a 10kW ranges from $27,000 to $33,000, and a larger 20kW system around $40,000, all after rebates and with minimal battery capacity—typically 10-15kWh for a 10kW system and 15-20kWh for larger setups.