On average, a 15 kW solar panel system costs $36,300, according to real-world quotes on the EnergySage Marketplace from 2025 data. Department of Energy (DOE) Solar Energy Technologies Office (SETO) and its national laboratory partners analyze cost data for U. solar photovoltaic (PV) systems to develop cost benchmarks. These benchmarks help measure progress toward goals for reducing solar electricity costs. Off-grid solar system prices range from $8,000 for a 5kW cabin setup to $28,000+ for a 15kW industrial kit. At Shielden, we cut costs by manufacturing panels, batteries, and inverters in-house – no middlemen. Why trust EnergySage? How much does a 15 kW solar system cost? How much electricity will a 15 kW solar system produce? Where can you purchase a 15 kW solar system? Is a 15 kW solar system right for you?NLR analyzes the total costs associated with installing photovoltaic (PV) systems for residential rooftop, commercial rooftop, and utility-scale ground-mount systems. This work has grown to include cost models for solar-plus-storage systems.