You can look at a cow as a solar energy gathering and processing plant. She goes out and gathers grass growing in the sunlight and process it into milk and cream and beef which we find much more palatable then grass. The energy we spend on caring for the cow makes her life easier and more productive. You wouldn't get any milk out of a cow out on the free range in the winter but give her a free stall barn to shelter her from the winter and a bunk full of feed saved from the summer surplus and she can be milked ten months of the year.
Compared to the efficiency of photovoltaic panels she is a marvel of modern engineering.





