The cost of a solar panel system in Missouri depends on its size, location, and the specific components used. On average, homeowners can expect to pay between $2.50 and $4.00 per watt for a complete solar installation. For a standard 5-kilowatt system, this translates to a total cost of $12,500 to $20,000. However, it’s important to note that prices have been steadily declining in recent years, making solar power more accessible than ever. Coupled with federal incentives like the solar tax credit, which offers a 30% credit on installation costs, the financial attractiveness of solar power continues to grow. The ROI in Missouri typically ranges from 6-8 years, thanks to the state’s average electricity rates of 10-11 cents per kilowatt-hour.