a) Family Smith has already installed PV in their house. Now, they also want to cover their needs for warm water with solar energy. For this, they consider having a solar thermal water heating system. Considering that the need for warm water is 100L/day, the water has to be heated from 10 to 60ºC and the specific heat capacity of liquid water is 4.18 J/gK.

Question

What is the total energy, in Wh/day, that the system will need to supply to cover the warm water demand?

b) Considering an efficiency of 70% and an irradiance of 1000W/m2 for 3 equivalent sun hours, how much collector area, in m2, will be needed to cover the demand?

c) If only half of the hot water needed has to be stored, at least how big, in L, should the storage tank be?

Answer 1

a) 5805.36
b) 2.76
c) 50