3kw of panels may produce 20 kw/h per day on the planet Mercury, not so much here on Earth.
It averages 4kw/h per 1kw of panels giving 3kw of panels an average of 12kw/h per day. That's 96c per day, or $350 per year giving a payback time of 20 years. Then the system is dead. No payback sorry.