3 ms·
Not trivial. Factors: Local labor costs, PV import tariffs, net metering arrangement, roof space and tilt angle, electricity prices, local solar irradiance leve
by hackerlight 2y ago
Not trivial. Factors: Local labor costs, PV import tariffs, net metering arrangement, roof space and tilt angle, electricity prices, local solar irradiance levels, solar seasonality, and large cost difference between grid tie versus hybrid battery systems.
If you live in a reasonably sunny country, the shorthand you can use is 4.5*(system size in KW), which equals the daily number of kWh your system will produce. Say that number is 30kWh. Then multiply 30 by your per kWh electricity costs. Say $0.2*30. That's your daily savings estimate, $6. Then you can figure out how many years to ROI by comparing it to the system cost. This approach will be more or less accurate if you have a battery or a nice net metering arrangement. It will be less accurate without either of these things.