Scale and geography of mining electricity
Bitcoin mining consumes roughly 100-150 TWh per year (estimates vary; this exceeds the annual electricity use of some small nations). Unlike traditional data centers, which cluster in regions with cheap power grids, Bitcoin mining is geographically distributed across wherever electricity is cheapest. Major mining regions include Iceland (geothermal), China (hydro, coal), Kazakhstan (coal, wind), and Texas (wind, natural gas).
The mix of energy sources is heterogeneous. Some miners source 100% renewable power (hydro from Icelandic dams, wind from West Texas), while others use coal and stranded fossil-fuel assets (natural gas from oil wells that would flare otherwise). The network-wide breakdown sits somewhere around 30-40% renewable and 60-70% fossil, though estimates fluctuate based on hashrate distribution and regional energy seasonality.
Why mining consumes so much energy
Mining secures the Bitcoin network by solving computationally hard puzzles (SHA-256 hashing) that prove work and prevent forgery. This security-by-computation model is intentional: the energy cost makes attacking the network prohibitively expensive. Miners compete to solve puzzles first and earn block rewards, and more miners join when the price is high, raising total energy use. This creates a feedback loop: higher Bitcoin price, more mining, higher energy cost, and vice versa during price downturns.