A solar flux of 700 W/m2 is incident on a flat-plate solar collector used to heat water. The area of the collector is 3 m2, and 90% of the solar radiation passes through the cover glass and is absorbed by the absorber plate. The remaining 10% is deflected away from the collector. Water flows through thetube passages on the backside of the absorber plate and is heatedfrom an inlet temperature Ti to an outlet temperatureTo . The cover glass, operating at a temperature of30oC, has an emissivity of 0.94 and experiencesradiation exchange with the sky at -10oC. The convectioncoefficient between the cover glass and the ambient air at25oC is 10 W/m2K.

---> How would you perform an overall energy balance on thecollector to get an expression for the rate at which useful heat iscollected per unit area(heat flux).
What would the value of thisbe?