Estimates: Usage/day = 30kWHr, Sunshine Hr/day = 4, Efficiency = 75%, Array Wattage = 10kW, Lifetime = 25yrs
Wires/Breaker/Panel = $0.25 per watt or $2,500
Railing/Support = $0.25 per watt or $2,500
Solar Panel = $1 per watt or $10,000
Charge Controller = $1 per watt or $10,000
Battery = $1 per watt or $10,000 (with 2 replacement over 25yrs for a real cost of $3/W or $30,000)
Inverter = $1 per watt or $10,000
Labor = $3 per watt or $30,000
Backup Propane/NG Generator = 2kW generator for $1 per watt, for when there is bad weather.
Propane/NG Tank (Heating + Backup + Cooking) = ???
Here is a good website to help you out.
Personally I only use about 3kWHr per day vs the avg of 30kWhr so a system for me would cost 1/10th. But maybe you have a workshop
and so you might need a system that is 3times the avg american house. If it is grid tied you can ignore the cost for batteries and you wouldn't need both charge controllers and inverters, only one. You will have to replace your roof and the entire system every 25yrs, except for the battery. that needs to be replace 2times aka every 8yrs for real cost of $3 per watt. The batteries similar to labor cost as much as the rest of the system combined (Inverter+Charge Controller+Solar Panel+Support+Misc). So if you are trying to save some cash, you now know where to save money, do most of the labor yourself and use less battery power at night so that your battery last longer. It doesn't matter if you use Lead Battery or LiFePO4 batter over the 25yr lifetime it works out to be about the same. So people get hang up on the battery or solar panel tech/efficiency but for the amount of actual usable wattage it all works out to be the same cost, it like buying a $2,000 Dell or HP computer it all works out to be about the same power, the only difference might be customer service.