(EN) Cambridge Bitcoin Electricity Consumption Index (CBECI), su ccaf.io. URL consultato il 3 novembre 2023.
«Bitcoin’s energy footprint is linked to block production, not transaction processing. This means that the number of transactions within a block has no impact on its energy expenditure: for a given difficulty level, a full block containing thousands of transactions has the same electricity footprint as an empty block with no transactions. The widespread misconception that Bitcoin’s energy consumption rises with a growing number of transactions seems to have its origins in the popular energy cost per transaction metric. Often used to compare the ‘energy efficiency’ of different payment systems, it is a purely theoretical measure that has little practical relevance without additional context.
A meaningful comparison would first require a uniform definition of the term ‘transaction’. Bitcoin transactions can contain hidden semantics that may not be immediately apparent. For instance, a single transaction in Bitcoin may be bundling together hundreds of smaller payments to individual addresses. It may also correspond to a settlement of thousands of off-chain transactions that took place on second-layer solutions (e.g. opening and closing channels in the Lightning Network). It could also potentially represent millions of timestamped data points using open protocols such as OpenTimestamps.
Electronic payments are typically enabled through closed book-entry systems where customer accounts are centrally maintained by operators such as commercial banks or credit card companies. These institutions act as gatekeepers that exercise discretionary control over the payment network: this includes access policies (who can use the service), risk procedures and compliance (what actions can be done), and account management (what assets and transactions are allowed). As a result, users may be denied access, have accounts closed, or see transactions flagged and reversed.
In contrast, Bitcoin is a permissionless system that operates without a central authority. Users are free to use the network and transact without prior approval by others. Like physical cash, users can transact pseudonymously and remain in full control of their own funds (self-custody). No single actor can unilaterally seize assets, reverse transactions, or change the ruleset. The Bitcoin network also operates 24/7 around the clock and is cross-jurisdictional by nature. These properties do come at significant costs, however – a large network with massive redundancies, scalability and performance constraints, slow coordination and decision-making, and, above all, an expensive and energy-intensive consensus mechanism»
