Converting sunlight to electricity with solar cells has an efficiency of 15%. It
ID: 1775068 • Letter: C
Question
Converting sunlight to electricity with solar cells has an efficiency of 15%. It's possible to achieve a higher efficiency (though currently at higher cost) by using concentrated sunlight as the hot reservoir of a heat engine. Each dish in (Figure 1) concentrates sunlight on one side of a heat engine, producing a hot-reservoir temperature of 600 C . The cold reservoir, ambient air, is approximately 30 C. The actual working efficiency of this device is 30%.
What is the theoretical maximum efficiency?
Explanation / Answer
Write the expression for the Carnot maximum efficiency .
Efficiency=[1-(cold body temperature/hot body temperature)]
=[1-{(30+273)/(600+273)}]
=0.653
=65.3%
Hence maximum theoretical efficiency is 65.3%.