16,000 megawatts is the energy consumption of 701 Swiss hydroelectric plants. This is also the amount of energy wasted in 2025 due to unsuccessful bitcoin mining attempts. In this competition between powerful computers to validate transactions and win bitcoins, there are winners, and many losers, including the planet.
A new study from the journal PNAS Nexus highlights the colossal energy waste caused by cutthroat competition from bitcoin miners – often companies – all seeking to validate the same blocks of transactions, as Live Science explains.
Bitcoin is based on a validation system by “proof of work”: To validate a new block of transactions and obtain a bitcoin reward, miners must solve a complex mathematical problem using considerable computing power. The more efficient equipment a miner has, the more likely he is to win.
Energy thrown down the drain
However, the competition has become so intense that the gap between the first and second miners is sometimes measured in fractions of a second. This results in “accidental forks” when two competing blocks are validated almost simultaneously. Only one will ultimately prevail, the one on which the following chain of blocks will be the longest, while the other will be rejected, making all the energy spent to produce it useless.
The researchers emphasize that these accidents constitute a structural inefficiency of the bitcoin protocol, which increases its environmental footprint. The study also looked at the distribution of “pools” mining, these groups of miners who combine their resources to maximize their chances of success.
Result: the sector is increasingly concentrated, three pools only produce more than half of the new blocks. This concentration raises fears of a major risk: if an actor controls more than half of the network’s computing power, it could in theory impose its own version of transactions and therefore cheat, for example by spending the same bitcoins twice.
It could also give miners excessive power over transaction fees: a few large miners could intentionally delay certain transactions, forcing users to pay more to have theirs processed quickly.
Bitcoin largely dominates the cryptocurrency market. It has a capitalization of more than $1.1 trillion, more than 80% more than Ethereum, its main rival. But unlike bitcoin, Ethereum does not use the “proof of work” but another mechanism, the “proof of stake”much less demanding in calculation and therefore in energy than bitcoin.
