The cost range for a 50kW solar system in the United States generally spans from about $40,000 to $95,000 before incentives, with typical installed price around $70,000 on average. Costs hinge on equipment quality, installation complexity, permitting requirements, and. Compare price and performance of the Top Brands to find the best 50 kW solar system. Buy the lowest cost 50 kW solar kit priced from $1. For home or business, save money on monthly power bills. The term 50 kW solar plant cost refers to the total investment required to build a solar power system with a 50 kilowatt capacity. Investors also factor in energy output and payback period. How much does a 30kW 40kW 50kW 80kW solar system cost? PVMars lists the costs of 30kW, 40kW, 50kW, and 80kW solar plants here (Gel battery design). If you want the price of a lithium battery design, please click on the product page of the corresponding model to find out. 75 per watt, as mentioned below.