Sustainability Disclosure - BTC

Quantitative information

S.1 Name
Digital Currency Services B.V.

S.2 Relevant legal entity identifier
724500QZRWKCU8D2L569

S.3 Name of the crypto-asset
Bitcoin [BTC]

S.6 Beginning of the period to which the disclosure relates
2024-06-14

S.7 End of the period to which the disclosure relates
2025-06-14

S.8 Energy consumption
208078 GWh/a

S.10 Renewable energy consumption
15.11%

S.11 Energy intensity
14.45 kWh

S.12 Scope 1 DLT GHG emission - Controlled
0.00000 tCO2e

S.13 Scope 2 DLT GHG emission - Purchased
85727324.803 tCO2e

S.14 GHG intensity
5.95229 kgCO2e

Qualitative information

S.4 Consensus Mechanism

Bitcoin uses a Proof-of-Work (PoW) consensus mechanism, known as Nakamoto consensus, to achieve decentralized agreement on the state of its blockchain. Miners use computational power to solve complex cryptographic puzzles, securing the network and validating transactions without a central authority. The first miner to solve the puzzle earns bitcoin and broadcasts the new block. This mechanism has maintained Bitcoin's stability and security for over 15 years.

S.5 Incentive Mechanisms and Applicable Fees

I) Incentive mechanism

Purpose: Enables secure, trustless, and decentralized verification of transactions.
Security: To alter history, a malicious actor would need over 51% of the network's total computing power (hash rate).
Process: Miners compete to find a specific hash value for a block, requiring immense energy and hardware.
Validation: Other nodes in the network easily verify the solution, ensuring the network only accepts valid transactions.
Longest Chain Rule: Nodes follow the "longest chain" rule (technically the chain with the most accumulated work).
This mechanism has maintained Bitcoin's stability and security for over 15 years.

II) Applicable Fees

Fees act as a priority mechanism. Because block space is limited, transactions with higher fees are typically prioritized by miners.

Fee Structure: Fees are usually calculated based on the size of the transaction in bytes, not the amount of Bitcoin sent.
Satoshis per Byte (sat/vB): Miners prioritize transactions that offer the highest fees per unit of block space (measured in satoshis per byte).
Voluntary & Competitive: Fees are voluntary but necessary for timely confirmation. During high network congestion, fees increase as users compete for space in the next block.
Optimal Fee Estimation: Tools such as mempool.space help users estimate the necessary fee to include a transaction in the next block.

Factors Affecting Fee Costs

Network Congestion: High transaction volume increases fees.
Transaction Complexity: Transactions with more inputs and outputs (more data) are more expensive.
SegWit and Native SegWit: Using modern address formats (starting with '3' or 'bc1') reduces data size and transaction fees compared to legacy addresses ('1').
Batching: Sending payments to multiple recipients in one transaction reduces the cost per recipient.

S.9 Energy consumption sources and methodologies

For the calculation of energy consumptions, the so called "bottom-up" approach is being used. The nodes are considered to be the central factor for the energy consumption of the network. These assumptions are made on the basis of empirical findings through the use of public information sites, open-source crawlers and crawlers developed in-house. The main determinants for estimating the hardware used within the network are the requirements for operating the client software. The energy consumption of the hardware devices was measured in certified test laboratories. When calculating the energy consumption, we used - if available - the Functionally Fungible Group Digital Token Identifier (FFG DTI) to determine all implementations of the asset of question in scope and we update the mappings regulary, based on data of the Digital Token Identifier Foundation. The information regarding the hardware used and the number of participants in the network is based on assumptions that are verified with best effort using empirical data. In general, participants are assumed to be largely economically rational. As a precautionary principle, we make assumptions on the conservative side when in doubt, i.e. making higher estimates for the adverse impacts.

S.15 Key energy sources and methodologies

To determine the proportion of renewable energy usage, the locations of the nodes are to be determined using public information sites, open-source crawlers and crawlers developed in-house. If no information is available on the geographic distribution of the nodes, reference networks are used which are comparable in terms of their incentivization structure and consensus mechanism. This geo-information is merged with public information from the European Environment Agency (EEA) and thus determined. The intensity is calculated as the marginal energy cost wrt. one more transaction.

S.16 Key GHG sources and methodologies

To determine the GHG Emissions, the locations of the nodes are to be determined using public information sites, open-source crawlers and crawlers developed in-house. If no information is available on the geographic distribution of the nodes, reference networks are used which are comparable in terms of their incentivization structure and consensus mechanism. This geo-information is merged with public information from Our World in Data, see citation. The intensity is calculated as the marginal emission wrt. one more transaction.

Ember (2025); Energy Institute - Statistical Review of World Energy (2024) – with major processing by Our World in Data. “Carbon intensity of electricity generation – Ember and Energy Institute” [dataset]. Ember, “Yearly Electricity Data Europe”; Ember, “Yearly Electricity Data”; Energy Institute, “Statistical Review of World Energy” [original data]. Retrieved from https://ourworldindata.org/grapher/carbon-intensity-electricity Licenced under CC BY 4.0.