There are a lot of misconceptions about Bitcoin mining - energy usage, we are going to debunk a few of them below, but first we need to understand what is "Bitcoin mining". The Bitcoin network uses the Proof Of Work(POW) consensus algorithm to prevent double spending attack or theft, as Satoshi said that's the only way we can achieve digital scarcity online because there is a heavy cost on cheating and almost impossible to crack after reaching a certain level of security, every body is better off being honest working to receive the money since doing anything else would put you in a disadvantage. But why is it using so much energy? Well Bitcoin has something called "difficulty adjustment" that's like an internal thermostat that keeps the network stable so coins don't get release too fast and so transactions don't get processed too fast neither too slow(it stays around 10min in average). When a miner double its capacity in terms of energy or computer efficiency the network readjust itself up to absorb the load and if a miner goes offline the network readjust itself down, this process happens every 2 weeks approximately or 2016 blocks.
All of this is to prevent inflation or unfair advantages to a certain group that doesn't provide real value to society. The majority of problems in most societies today are due to the fact that governments and central banks are able to print money for free that everybody else have to work for, fixing this is fixing half of our problems.
In order for a Bitcoin miner to stay competitive they need to use the cheapest energy they can find and not the expensive energies used in manufacturing and houses but they need to find stranded energy or energy that would have gone to waste otherwise, these energies are: hydro-electric dams that produce electricity without enough demands for consumption, windmill farms, oil field natural gas that would have gone venting into the atmosphere, landfill methane gas that would have gone flared into the atmosphere, etc. Note that heat(miners byproduct) of these energies can be repurpose for home heating or manufacturing heating in most places.
Not only that, but also energy is everywhere around us and Bitcoin mining profit incentives will help us find new ways to generate much energy in the process which will make us more prosperous as the more energy we generate and use the better off we are and the richer we become, those who don't use energy will more likely stay poor and will often cause much more damage to their environment. Here is a video of a small business owner in Manitoba Canada using Bitcoin mining for heating in his business:
Here some more misconceptions debunked below:
Q. Can a big miner 50% attack the network?
A. Having more hashrate does not give you any more power to steal from other people on the network, you can only double spend your own coins. Plus with over 50% of hashrate you're making way more money staying honest than deciding to cheat.
Q. Why Use Proof of Work?
A. Proof of Work is the only way you can have honest money, the energy is to prevent the stealing and the more energy the better. Climate change is a scam prop up by central bank money printers to find more excuse to print more money to steal for the people.
Q. Why so much energy?
A. Energy usage is not a problem, the more energy a society uses the more advance that society become, the more energy your money uses the stronger is your money. There is an infinite amount of energy all around us, Bitcoin is helping us discover more and transforming them into electricity we need. Most of the energy Bitcoin uses were going to be wasted anyway because it wouldn't make sense for miners to compete using higher electricity rates, Bitcoin mining most energy sources are: unwanted excess hydro-electric power, landfill Methane gas, excess windmill power, excess natural gas from the oil field, etc. We will discover more ways to capture energy such as nuclear to advance society.
Q. Why not the Ethereum Proof of Stake?
A.Ethereum Proof of Stake is the same as having a the central bank creating money for free without any real cost. It's not an improvement it's a return to the stone age where a very few control the money and all the resources and everyone has to go along with whatever they say. Bitcoin has no leader, no road map, no organization it's all thanks to the proof of work and the nodes spread all across the world.