Motivation: Local energy communities represent a compelling use case for Blockchain-based Information Systems (BISs), where mutually distrusting participants must share and verify energy data without relying on centralized authorities. However, integrating real-time IoT monitoring, photovoltaic (PV) generation modeling, and blockchain infrastructures raises challenges of scalability, governance, transparency, and data management. Objective: This study investigates the design of a BIS that integrates IoT-based energy monitoring, PV system simulation, and blockchain transaction management to provide a transparent, efficient, and fair framework for decentralized energy communities. Methods: This study presents a framework design and validation methodology that combines empirical monitoring with simulation-based assessment. Real household electricity consumption was monitored over six days using smart meters interfaced through MQTT to a Raspberry Pi. Photovoltaic generation was simulated using PVsyst with site-specific meteorological data 1642 kWh/m 2 . Energy surplus scenarios were modeled by combining measured consumption with simulated PV output and submitted to a Hyperledger Fabric network to measure transaction performance. Multiple blockchain platforms were evaluated against latency, throughput, energy overhead, and cost metrics. Results: Measured blockchain performance on operational hardware shows permissioned networks with PBFT consensus achieve 2 . 35 ± 0 . 11 second latency and 0 . 99 ± 0 . 07 % energy overhead for 10-household communities. Simulated PV optimization demonstrates that 35° panel tilt increases annual yield by 15.9% over a horizontal baseline (3877 kWh/year baseline; 4495 kWh/year optimised) with 75.1% performance ratio. Infrastructure costs are measured at 240 EUR/household for the validated 10-household baseline and projected to scale to 40 EUR/household at 60-household deployments through fixed cost distribution, with intermediate validation through Hyperledger Caliper simulations confirming sub-linear latency scaling to 20 households (2.68 ± 0.18 s). The 10-household configuration represents a pilot-scale baseline for controlled validation, with demonstrated architectural scalability through simulation. The framework validation demonstrates technical feasibility and quantifies design trade-offs in consensus selection, data management, and system optimization. Conclusion: This work contributes a reproducible validation framework for blockchain-based energy management systems, validated through controlled component testing prior to field deployment. The methodology addresses scalability, governance, and transparency challenges while offering practical design guidelines for implementing fair and efficient local energy communities.

Smart contracts are programs whose business logic runs in a decentralized architecture named blockchain where each of the executing nodes trusts and agrees with the execution outcomes. Blockchain is an isolated execution environment, so smart contracts cannot access external data by themselves. The blockchain Oracle, or simply Oracle, is the software that allows smart contracts to interact with the outside world. In the past, a wide variety of studies have examined the oracles from various perspectives such as their implementation characteristics and their reliability. Unlike some other studies, this paper analyzes the use of Oracles through a static analysis of smart contracts. First, we analyze the source code of a corpus of over 40K smart contracts to find the most blockchain Oracles used by the Ethereum blockchain. On the basis of previous works, we examine the features of the most used blockchain Oracles in Ethereum. Lastly, we discussed our findings and the possible reasons why some blockchain oracles are more widely used than others. The purpose of this study is to shed light on how and which oracles are actually used by Ethereum smart contracts, as an alternative to other very interesting studies that analysed the blockchain oracle characteristics.

Solana is a blockchain platform with its own token, called SOL or Solana. As a blockchain network, Solana is a de-centralized public ledger for verifying and recording transactions. The Solana blockchain has smart contract capabilities. Unlike other blockchains, such as Ethereum, there is no repository or tool where to check for the source code of the smart contracts stored in the blockchain. These tools are crucial to increase the users' trust in this type of technology. Indeed, one of the most important features of the blockchain is transparency, i.e. the possibility to see the source code of the program to use, or in which the users wish to invest. However, in the blockchains that support smart contracts, what is stored is not the source code of the smart contract written in a high-level program understandable to humans, but the bytecode, i.e. a low-level code made for the hardware to be executed. For some blockchains, such as Ethereum, there are different tools, such as integrated development environment (IDE), that allow to verify that the smart contracts' source code corresponds to the bytecode installed on the nodes of the blockchain. Moreover, there are different repositories that collect smart contracts written in a high-level programming language and their corresponding bytecode. However, for the Solana blockchain, all these tools do not exist yet. The study proposes a web tool that allows verifying the ownership of a smart contract, i. e. the smart contracts' source code written in a high-level programming language corresponds to the bytecode deployed in the Solana blockchain. Moreover, we have published smart contracts' source code written in high-level programming via a public service that can be used by researchers, smart contract developers, and blockchain not-expert users.

Solana is a public blockchain platform, launched in April 2018, that aims to increase scalability when compared to other blockchains without compromising decentralization and security. It supports smart contracts and the creation of decentralized applications (DApps). The study aims to collect data from the Solana blockchain and verify some of its properties such as its transactions' throughput, i.e. the rate at which valid transactions are committed into a block by the Solana blockchain during a one second interval of time (TPS). The data were collected over the period of two months (14 October - 15 December) and made public on a GitHub repository. The results of our data analysis show how the average transactions' throughput is about 2812 TPS and that the fees paid by users to have the transactions confirmed are on average much lower than the fees users pay for other blockchains that support the same functions, such as smart contract and the creation of DApps. The paper sheds light on the mechanisms of Solana blockchain that, according to their founders, promises to solve the scalability problem without sacrificing decentralization and security.

The Ethereum blockchain enables executing and recording smart contracts. The smart contracts can facilitate, verify, and implement the negotiation between multiple parties, also guaranteeing transactions without a traditional legal entity. Many tools supporting the smart contracts development in different areas are flourishing because in Ethereum blockchain valuable assets are often involved. Some of the tools help the developer to find security vulnerabilities via static and/or dynamic analysis or to reduce the Gas fees consumption. Despite the plethora of such tools, there is no tool supporting smart contracts evaluation and analysis via a graphical representation for expert developers.The paper embraces this way to facilitate the developers’ analysis activity, by proposing a graphical representation model to visualize smart contract source code. The paper makes available a tool via a web interface, which accepts the smart contract address as an input and produces a graphical representation of the smart contract as an output. The graphical representation can help developers to better understand the structure of smart contracts and share it with other developers. Moreover, some metrics, such as the relations among smart contracts, are easier to be understood via "spatial" than "tabular" representation. Indeed, representing smart contracts’ metrics via visual representation facilitates the developers, who are used to analyse the source code by directly inspecting it or using other tools that provide the metrics in a table format. Finally, the paper provides detailed data regarding a smart contract to the developers and proposes a graphical representation of the smart contracts without obscuration of details, also highlighting areas of the code that are possibly too big in size and/or too complex via a diagram displaying their connections.

The practice of writing smart contracts for the Ethereum blockchain is quite recent and still in development. A blockchain developer should expect constant changes in the security software field, as new bugs and security risks are discovered, and new good practices are developed. Following the security practices accepted in the blockchain community is not enough to ensure the writing of secure smart contracts. The paper aims to study the practice of code cloning among the smart contracts by analyzing two corpora. The first corpus, the "Smart-Corpus", includes smart contracts already deployed in the Ethereum blockchain. The second corpus, the "Open-Zeppelin's Solidity Library", is supervised by a community of developers who constantly take care to increase the security and efficiency of the smart contracts included in the corpus. From the comparative analysis of the corpora, we observe that the smart contracts developers frequently duplicate the code by cloning already existing smart contracts which are not part of the "OpenZeppelin corpus". In particular, we found that 79.1% of smart contracts contain duplicated code and only 18.4% of smart contracts reuse the code by implementing a smart corpus belonging to the OpenZeppelin repository. The paper discusses the advantages and the disadvantages of code duplication in the Ethereum blockchain ecosystem, and suggests to refer to the smart contracts of the OpenZeppelin's Solidity Library. The Ethereum blockchain community can indeed benefit from using the tested code presented in OpenZeppelin's Solidity Library to increase its security.