Stellar (XLM) sustainability report

Stellar is present on the following networks: Stellar.

Stellar operates on a distinctive consensus mechanism known as the Stellar Consensus Protocol (SCP), which is fundamentally built upon the principles of Federated Byzantine Agreement (FBA). This design enables decentralized and leaderless consensus, eliminating the requirement for a closed, pre-defined group of trusted participants often found in traditional Byzantine Fault Tolerant (BFT) systems. Instead, SCP empowers each node within the Stellar network to independently select a specific set of other nodes it trusts, referred to as its "quorum slice." Consensus on the transaction state is achieved when these individual quorum slices sufficiently overlap and collectively agree on the proposed ledger modifications. The consensus process on Stellar involves several structured phases. Initially, transactions are submitted to the network, where nodes validate them against established rules such as sufficient balances and valid digital signatures. This is followed by a "Nomination Phase," where nodes propose values (representing potential transactions or ledger updates) they believe should be included in the upcoming ledger. Nodes actively communicate these nominations to their respective quorum slices. Through continuous voting and a federated agreement process among these slices, a set of candidate values emerges, with this phase persisting until a unified set of values is agreed upon. Subsequently, these agreed-upon values advance to the "Ballot Protocol," involving multiple rounds of voting where nodes either accept or reject the proposed values. Within their quorum slices, nodes exchange votes, and a value progresses to the next stage if it garners sufficient support across intersecting slices. Final acceptance and "externalization" of a value as the next state of the ledger occur once it successfully navigates through various stages, including preparation and confirmation. Following this, the ledger is updated, with all participating nodes reflecting the new, agreed-upon state. The inherent flexibility for nodes to choose their quorum slices fosters decentralization and resilience, allowing the network to maintain consensus even if certain nodes become faulty or malicious. This protocol is also noted for its efficiency, avoiding the energy-intensive mining processes characteristic of many blockchain systems, making it suitable for high-throughput applications.

Stellar is present on the following networks: Stellar.

The Stellar blockchain network utilizes a unique approach to incentive mechanisms and applicable fees, primarily underpinned by its Stellar Consensus Protocol (SCP), which is based on the Federated Byzantine Agreement (FBA) model. Diverging from traditional Proof of Work (PoW) or Proof of Stake (PoS) systems, Stellar deliberately does not rely on direct economic incentives such as mining rewards or staking rewards for validators. Instead, the network secures transactions and maintains integrity through intrinsic network mechanisms and a specific fee structure. The primary incentive for nodes to participate and act honestly stems from the inherent value derived from maintaining a secure, efficient, and reliable payment network. Organizations and individuals operating nodes benefit directly from the network's core functionality and its capacity to facilitate rapid and low-cost transactions. This model encourages active participation by aligning the interests of nodes with the overall health and utility of the Stellar network. Furthermore, the FBA model, characterized by "quorum slices" where each node selects trusted peers, promotes decentralization. This flexibility in node selection reduces the risk of single points of failure and enhances the network's resilience against attacks, thereby providing a robust platform whose value incentivizes its upkeep. Regarding applicable fees, Stellar employs a flat fee structure designed for predictability and efficiency. Each transaction on the Stellar network incurs a minimal base fee of 0.00001 XLM. This exceedingly low and consistent fee makes Stellar particularly well-suited for high-volume transactions and micropayments. A crucial function of this transaction fee is spam prevention; by requiring a small cost for every transaction, the network deters frivolous or malicious activities that could otherwise overwhelm its resources, ensuring efficient operation. These minimal fees are also intended to cover the basic operational costs of the network, supporting its self-sustainability without imposing a significant financial burden on users. Beyond transaction fees, Stellar implements reserve requirements to further protect network integrity and manage resource usage. For instance, creating a new account necessitates a minimum balance of 1 XLM. Additional reserves are required for establishing "trustlines" and "offers" on the Stellar decentralized exchange (DEX), which collectively safeguard against spam and resource abuse while maintaining network efficiency.

Stellar is present on the following networks: Stellar.

The methodology for calculating the Stellar blockchain network's energy consumption adopts a "bottom-up" approach, where individual nodes are identified as the central determinant of the network's overall energy footprint. This comprehensive assessment begins by quantifying the energy usage of the network as a whole. Subsequently, for specific crypto-assets operating on Stellar, a proportional fraction of this total network energy consumption is attributed, based on the asset's activity within the network. This ensures that energy allocation is reflective of actual usage patterns. The foundational data for these calculations is derived from empirical findings, which are systematically gathered through a combination of publicly available information sites, sophisticated open-source crawlers, and proprietary in-house developed crawlers. These tools enable a thorough collection of data pertinent to the operational characteristics of the network. A critical component of this methodology involves estimating the hardware deployed across the network. These estimations are primarily guided by the technical specifications and requirements necessary for running the Stellar client software. The energy consumption profiles of these identified hardware devices are precisely measured in certified test laboratories, ensuring accuracy and reliability in the underlying energy data. Furthermore, to ensure a comprehensive scope, the Functionally Fungible Group Digital Token Identifier (FFG DTI) is utilized, where available, to pinpoint all implementations of crypto-assets relevant to the Stellar network. These mappings are subject to regular updates, drawing data from the Digital Token Identifier Foundation, to reflect any changes in the ecosystem. The information pertaining to the specific hardware used and the total number of participants active within the network is built upon a set of assumptions. These assumptions are meticulously verified through best efforts, leveraging empirical data to ensure their robustness. Generally, participants are presumed to behave in an economically rational manner. In instances of uncertainty, a precautionary principle is applied, leading to conservative assumptions that typically result in higher estimates for potential adverse impacts, thus providing a robust and cautious assessment of energy consumption.

Stellar is present on the following networks: Stellar.

The methodology for determining the proportion of renewable energy usage within the Stellar blockchain network involves a detailed process that identifies and analyzes the geographic distribution of its operational nodes. The initial step focuses on ascertaining the physical locations of these nodes. This is accomplished through diligent research utilizing public information sites, alongside the deployment of both open-source and internally developed crawlers designed to collect accurate geographical data. Should precise geographic information for all nodes prove unavailable, a pragmatic approach is adopted: reference networks are selected. These reference networks are carefully chosen based on their comparability to Stellar in terms of incentive structures and underlying consensus mechanisms. This ensures that the energy profiles and renewable energy penetration rates of these proxy networks provide a relevant and informed basis for estimation. Once geographical data, either direct or inferred from reference networks, is compiled, it is then meticulously integrated with extensive public information datasets. Specifically, data from "Our World in Data" is utilized, particularly their "Share of electricity generated by renewables - Ember and Energy Institute" dataset. This external data provides a global and regional overview of renewable energy generation, allowing for the calculation of the proportion of renewable energy consumed by the network's operations. The energy intensity of the Stellar network is precisely quantified as the marginal energy cost associated with processing one additional transaction. This metric offers a granular understanding of the energy footprint per unit of activity, providing insight into the efficiency of the network's operations. This robust methodology, which combines location-based energy mix data with empirically verified operational parameters, aims to provide a transparent and defensible assessment of the network's energy sources and their renewable penetration. The data sources for renewable electricity share are primarily Ember (2025) and the Energy Institute's Statistical Review of World Energy (2024), with substantial processing by Our World in Data, accessible via Share of electricity generated by renewables - Ember and Energy Institute.

Stellar is present on the following networks: Stellar.

The methodology for assessing the Greenhouse Gas (GHG) emissions associated with the Stellar blockchain network is systematically designed to pinpoint key emission sources and quantify their impact. A fundamental aspect of this assessment involves accurately determining the geographical locations of the network's operating nodes. This crucial data is gathered through a multi-faceted approach, including thorough searches of public information sites and the deployment of both open-source and proprietary in-house crawlers specifically developed to identify node distributions. In scenarios where comprehensive geographic information regarding node distribution is not readily available, the methodology incorporates a well-defined fallback procedure. In such cases, reference networks are employed. These reference networks are carefully chosen for their strong similarities to Stellar, particularly in their incentive structures and consensus mechanisms, ensuring that any derived estimates are as representative as possible. The geographical data, whether directly observed or inferred from comparable networks, is then meticulously integrated with publicly accessible data. A primary source for this integration is "Our World in Data," specifically leveraging their "Carbon intensity of electricity generation - Ember and Energy Institute" dataset. This dataset provides vital information on the carbon footprint of electricity generation across various regions, allowing for a precise calculation of the GHG emissions linked to the network's electricity consumption. The GHG intensity of the Stellar network is calculated as the marginal emission generated by processing one additional transaction. This metric is instrumental in understanding the environmental impact per unit of activity, offering insights into the efficiency of the network's operational processes from an emissions perspective. This comprehensive methodology, by combining detailed geographical data on electricity grids with empirically validated operational characteristics, strives to provide a transparent and accurate quantification of the network's GHG emissions. The cited data sources for carbon intensity of electricity generation include Ember (2025) and the Energy Institute's Statistical Review of World Energy (2024), processed by Our World in Data, available at Carbon intensity of electricity generation - Ember and Energy Institute. This information is licensed under CC BY 4.0.