2. What are solar irradiance, solar irradiation, solar isolation and peak sun hours? (10 pts)

Solar Irradiance: Solar irradiance is the total heat energy received from sun per unit time and per unit area. Its unit is watts per square meter.

Solar irradiation: Both solar irradiation and solar isolation are a measure of time integrated solar energy. The solar energy received per unit area over a fixed time period (hour, day, month, year, ect.) is called solar irradiation or solar isolation.

Peak Sun hours: Peak sun hours are those hours of the day when we receive maximum magnitude of solar irradiation or isolation. Amount of irradiation keeps changing with seasons, altitude, etc.