Peer-to-peer (P2P) energy trading and energy communities have garnered much attention over in recent years due to increasing investments in local energy generation and storage assets. However, the efficiency to be gained from P2P trading, and the structure of local energy markets raise many important challenges. To analyse the efficiency of P2P energy markets, in this work, we consider two different popular approaches to peer-to-peer trading: centralised (through a central market maker/clearing entity) vs. fully decentralised (P2P), and explore the comparative economic benefits of these models. We focus on the metric of Gains from Trade (GT), given optimal P2P trading schedule computed by a schedule optimiser. In both local market models, benefits from trading are realised mainly due to the diversity in consumption behaviour and renewable energy generation between prosumers in an energy community. Both market models will lead to the most promising P2P contracts (the ones with the highest Gains from Trade) to be established first. Yet, we find diversity decreases quickly as more peer-to-peer energy contracts are established and more prosumers join the market, leading to significantly diminishing returns. In this work, we aim to quantify this effect using real-world data from two large-scale smart energy trials in the UK, i.e. the Low Carbon London project and the Thames Valley Vision project. Our experimental study shows that, for both market models, only a small number of P2P contracts, and only a fraction of total prosumers in the community are required to achieve the majority of the maximal potential Gains from Trade. We also study the effect that diversity in consumption profiles has on overall trading potential and dynamics in an energy community.

翻译：近年来，随着对本地能源发电与储能设施投资的增加，点对点（P2P）能源交易与能源社区受到广泛关注。然而，P2P交易所能实现的效率提升以及本地能源市场的结构仍面临诸多重要挑战。为分析P2P能源市场的效率，本研究考虑两种主流的点对点交易模式：集中式模式（通过中央做市商/清算实体）与完全去中心化模式（P2P），并探究这两种模式的经济效益差异。我们以交易收益（Gains from Trade, GT）为核心指标，基于调度优化器计算的最优P2P交易方案进行评估。在两种本地市场模型中，交易收益主要源于能源社区内产消者之间消费行为与可再生能源发电模式的差异性。两种市场模型均会优先建立最具收益潜力的P2P合约（即交易收益最高的合约）。然而，研究发现随着P2P能源合约的建立和更多产消者的加入，这种差异性会迅速降低，导致收益显著递减。本研究基于英国两项大规模智能能源试验的实际数据——即"低碳伦敦"项目与"泰晤士河谷愿景"项目——对该效应进行量化分析。实验结果表明，在两种市场模式下，仅需建立少量P2P合约并吸引社区内部分产消者参与，即可实现最大潜在交易收益的绝大部分。本文还进一步分析了消费特征差异性对能源社区整体交易潜力与动态演化规律的影响。