What is the best way to generate electricity using fresnel lens? I have a fresnel lens which I want to put to use for generating electricity. My house receives ample sunlight. What is the best way of going about it? Stirling engines, steam driven turbines are some of the options. I need to decide which is the most efficient. Cost is a factor but not a major one. The important thing is efficiency.
 A: Carnot efficiency is $1-\frac{T_{C}}{T_{H}}$. Let's assume $T_{C}$ is 300 K.
A solar panel can reach an efficiency of 20%, so let's try to beat that.
$\frac{T_{H}}{T_{C}} > \frac{1}{1 - 20\%} = \frac{5}{4}$
$T_{H}$ must reach a temperature of 375K given a perfect Carnot engine (which does not exist).
We can do a similar estimate using a somewhat more realistic efficiency estimate: https://en.wikipedia.org/wiki/Endoreversible_thermodynamics
to find a necessary high temperature of 468 K.
In either case, a high temperature is required to outperform a solar panel, which directly uses the light rather than turning it into heat first. At these temperatures, since you need to reach a temperature difference of 75-168 celsius using your fresnel lens, you could boil water or cook, to directly use the heat. That would be the most cost efficient and very energy efficient.
First you need to figure out what temperatures you can reach. If you want to use a steam turbine you need to be able to boil water, for example. All heat engine efficiencies depend on the temperature you can reach.
