30. Calculate the solar panel size
in Watt, Battery is kWh and
charge controller in Watt for the
following appliances. Consider
Losses are 5% controller losses,
50% battery DOD, 15% battery
losses, 25% solar panel losses,
solar radiation is 5 kWh/m2/day
Appliances: Bulb (4 Nos. of 40 W
running for 5 hours), Fan (2 Nos.
of 70 W running for 12 hours), TV (1
No. of 35 W running for 6 hours)
Answers
Explanation:
Lets assume that you want to install 10 solar panels rated at 100 Watts each and having a conversion efficiency of 18%. The total power output of the solar system can be calculated as:
Total Power Output=Total Area x Solar Irradiance x Conversion Efficiency
We know the required Total Output Power is 1000 Watts (10 panels x 100 Watts), the Solar Irradiance for a surface perpendicular to the Sun’s rays at sea level on a clear day is about 1000 Watt/m2 and the Conversion Efficiency is 18%. Plugging these number in the above equation we get:
1000 Watts=Total Areax1000 Watts/m^2 x 0.18
1000 Watts=Total Areax1000 Watts/m^2 x 0.18or
1000 Watts=Total Areax1000 Watts/m^2 x 0.18or Total Area = 5.56 m^2
I you are going to install all the panels in one line you would need a space of approximately 1 m x 5.56 m (each panel having a size of 1 m x 0.556 m) on your rooftop. There you go. You have a rough estimate of the space required by the solar panels of your system.
In addition
1. Do remember that solar panels are usually installed at an angle to the earth surface and this may change the results somewhat.
2. Imagine a solar panel has a conversion efficiency of 100% i.e. it converts all the solar energy into electrical energy then all you would need is a 1 m^2 solar panel to produce 1000 Watts of electrical energy.
Based on the above in my opinion the best formula is the first one
Area =(kw)/((kw/m^2)) but you have to consider the conversion efficiency in this formula.