What is a peak sun hour?
Solar intensity varies throughout the day and this affects the amount of solar power you can produce per hour. So while there may be 10 hours of daylight, your system isn’t performing at peak output for the entire 10 hours. In northern NSW your system is performing at peak output for a combined total of 4.5 hours. This figure is arrived at by condensing total daylight hours to give a standard unit of peak sun hours. For example, a 1.5kW system has the capability of producing 1500 watts hours when the sun is shining directly onto the panels for an hour (e.g. 12pm to 1pm). But the system might only produce 100 watt hours between 7am and 8am, 250 watt hours between 8am and 9am, 400 watt hours between 9am and 10am etc. If you condensed all of these smaller hourly production rates together for maximum production of 1500 watt hours you get 4.5 peak sun hours for Northern NSW. This figure is then used how much electricity your system can generate over a day / year.
