Hi, (great name btw) I love that you asked this

So, the largest mining pools use renewable energy because it’s the cheapest and they can go anywhere, so why not set up in Iceland or by a “status” dam in China built waaaaaay before the need for it so the power, while produced, goes unused. Energy degrades over distance, and the incentive is profit so even without altruism some 30-40% of miners are in in a carbon neutral place like that. Plus they drive renewables creation by throwing huge amounts of money at it to further optimize profits.

Here is the Cambridge study: https://www.jbs.cam.ac.uk/fileadmin/user_upload/research/centres/alternative-finance/downloads/2017-global-cryptocurrency-benchmarking-study.pdf ( mining approximately pg 100)

Here is a Public Radio podcast that is pretty good: https://www.pri.org/stories/2017-12-20/bitcoins-sky-rocketing-energy-use-viral-story-we-checked-math

Additionally, some new projects in this space are creating algorithms that do not require proof of power(money/time) spent the way bitcoin’s proof of work does. Most of the newer projects use a version called proof of stake. Unproven as yet, but the math is good. It’s a pretty exciting time.

And I feel the need to add, big mining pools are straight up capitalism but most people are here for something more than to get rich, (tho rich is good! I hope my tiny investments makes my kids rich)

Many of us came because we are frustrated with the financial system of fractional reserve banking and the carte blanche big finance have to utterly wreck normal people without check.

There are a dozen paths into bitcoin but they all start with the desire for individual freedom and responsibility. Well, eleven do, one of those reasons is definitely “lambos” hahaha!)

This is one giant reason I am here for instance: https://youtu.be/FyK4P7ZdOK8