A coordinative flexibility trading of hydrogen storage system aggregators with energy aggregators and grid: Blockchain-enabled decentralized decision making framework

In this paper, a blockchain-enabled, decentralized, smart-contract–based decision-making strategy is proposed and implemented to optimize the provision of flexibility between energy aggregators and the distribution grid. To this end, a multi-aggregator formulation is considered for trading energy in the wholesale energy market, where a blockchain-based smart contract governs the optimal trading decisions among participating aggregators. Distributed renewable energy systems such as solar and wind turbine based aggregators as market participants their inherent intermittency and unpredictability have driven the need for flexible energy storage solutions, such as hydrogen storage systems, to ensure reliable grid operation and optimal market participation. Although hydrogen energy storage systems (HESS) offer long-term energy stability, they generally have slower response characteristics than battery energy storage systems. Consequently, the integration of hydrogen and battery storage enables a sustained energy supply and improves the management of microgrid demand and surplus generation. This is one of the important consideration in this paper utilizing HSS based aggregator apart from renewable aggregator. A Day ahead market scheduling is proposed and a mixed integer based non-linear programming optimization model is framed where the non-linearities of electrolyzer and fuel cell are handled. Based on the optimized power levels of aggregators this framework employs an Ethereum blockchain network with a Solidity-based smart contract to automate trading decisions among the aggregators ensuring transparent, immutable, and tamper-proof recording of all energy trading transactions. The smart contract implements a flexibility-based optimal decision algorithm that determines whether power should be traded peer-to-peer between aggregators or routed through the distribution grid, based on real-time market prices and the availability of power to be sold or purchased.