Some estimates put the first human settlements in the Amazon at 32,000 to 39,000 years ago. Since that time, Amazon people have developed lifestyles that are well integrated with the benefits and constraints of rainforests.
An estimated 7-10 million Amerindians (the term for American Indigenous peoples) lived in American rainforests, half of them in Brazil, at the time of European arrival. When Pizarro arrived in Peru, more land was under cultivation and more food was being produced in the Andean region than today.
Let's say that the cost of the solar panel installation is 12,500 and the Reyes family pays 200 a month for electricity. in 40 years the Reyes family would have saved a lot of money on electricity.
f(480)=200(480) - 12,500
the Reyes family would save
83,500$ in 40 years.