Date : 01/01/2022

Introduction

Efficiency is the output energy to input energy into 100%.

Objective

We calculate efficiency because as much input energy as possible should be transferred to a useful energy store and to see how it can utilize the stored energy.

Material

1.Measuring Tape

2.Thermometer

Procedure

Firstly,we measure the following dimensions:

Diameter of evacuated tube = 5.5 cm

Length of evacuated tube = 174cm

Now,

Area of one evacuated tube collector= l * b

=5.5*174 = 957 cm2

But here total 32 evacuated tube

Hence,

total area of evacuated tube collector= 957*32 =30624cm2 =3.06m2

Temperature of water at 9am= 42°C

Temperature of water at 5pm=48°C

Capacity of storage water tank = 500LPD

energy in 1m2 = 813

Now,

Input = Total area of ETC× Energy in 1m² ×Time

= 3.06×813×8×3600

= 71.648 × 10⁶

Output= Capacity of storage tank × 4.186 × Temperature difference

= 500 × 10³ × 4.186 × 6

= 12.558 × 10⁶

Therefore,

Efficiency of solar water heater= Output/Input

= 12.558 × 10⁶ / 71.648 ×10⁶

= 0.1752

= 17%

Conclusion

The efficiency of calculated solar water heater is 17%.This efficiency is very low because the dust on the evacuated tube was not cleaned.