Expect the cost per watt to be between $2 and $3. As of publishing, the average cost per watt is $2.84. Most solar companies set the price according to the solar system's wattage. A solar installation's “cost per watt” is a little like the “price per square foot” when you buy a house.
[pdf] Storage enables electricity systems to remain in balance despite variations in wind and solar availability, allowing for cost-effective deep decarbonization while maintaining reliability.
[pdf] In a 6 kW residential system (total cost around $12,000–$15,000 installed), the inverter typically accounts for $1,200–$2,000. In a 12 kW system (around $25,000–$30,000 total), the inverter share can reach $3,000+. This means the inverter cost scales roughly $0.20–$0.30 per watt.
[pdf] As of recent estimates, the average cost is around $250 to $400 per kilowatt-hour (kWh) of storage capacity, equating to approximately $0.25 to $0.40 per watt, depending on system design and size.
[pdf] 
