A promising energy carrier and storage solution for integrating renewable energies into the power grid currently being investigated is hydrogen produced via electrolysis. It already serves various purposes, but it might also enable the development of hydrogen-based electricity storage systems made up of electrolyzers, hydrogen storage systems, and generators (fuel cells or engines). The adoption of hydrogen-based technologies is strictly linked to the electrification of end uses and to multicarrier energy grids. This study introduces a generic method to integrate and optimize the sizing and operation phases of hydrogen-based power systems using an energy hub optimization model, which can manage and coordinate multiple energy carriers and equipment. Furthermore, the uncertainty related to renewables and final demands was carefully assessed. A case study on an urban microgrid with high hydrogen demand for mobility demonstrates the method’s applicability, showing how the multi-objective optimization of hydrogen-based power systems can reduce total costs, primary energy demand, and carbon equivalent emissions for both power grids and mobility down to −145%. Furthermore, the adoption of the uncertainty assessment can give additional benefits, allowing a downsizing of the equipment.

This paper presents an assessment of the levelized cost of clean hydrogen produced in Sicily, a region in Southern Italy particularly rich in renewable energy and where nearly 50% of Italy’s refineries are located, making a comparison between on-site production, that is, near the end users who will use the hydrogen, and centralized production, comparing the costs obtained by employing the two types of electrolyzers already commercially available. In the study for centralized production, the scale factor method was applied on the costs of electrolyzers, and the optimal transport modes were considered based on the distance and amount of hydrogen to be transported. The results obtained indicate higher prices for hydrogen produced locally (from about 7 €/kg to 10 €/kg) and lower prices (from 2.66 €/kg to 5.80 €/kg) for hydrogen produced in centralized plants due to economies of scale and higher conversion efficiencies. How-ever, meeting the demand for clean hydrogen at minimal cost requires hydrogen distribution pipelines to transport it from centralized production sites to users, which currently do not exist in Sicily, as well as a significant amount of renewable energy ranging from 1.4 to 1.7 TWh per year to cover only 16% of refineries’ hydrogen needs.

The energy transition is a challenge in which all countries in the world are involved to date with the aim of achieving climate neutrality. Green hydrogen produced by electrolysis through energy from renewable sources, can play a key role in the energy transition replacing fossil fuels used in industrial processes and heavy-duty transport. The widespread diffusion and massive adoption of this new and clean fuel, as well as the creation of national, regional, and international markets, depend heavily on traceability tools that certify its origin, creating transparency and stimulating demand. In this context, new information technologies such as Blockchain, thanks to their characteristics, could solve the problems associated with the traceability of green hydrogen, thus contributing to its diffusion. This paper describes a laboratory-developed system for green hydrogen production via electrolysis and proposes a Blockchain architecture for its tracking and certification.

Hydrogen is a zero-emission fuel that, if produced from renewable sources (so-called green hydrogen), can provide a significant contribution in the decarbonization of several sectors. The main drawback that still hinders its deployment is its high cost, as well as critical operational issues related to the entire supply chain, both for safety and efficiency reasons. Incentives and certification schemes are needed to support the green hydrogen. In this paper, with the aim to identify the green hydrogen supply chain and associated costs, an energy hub with electricity and hydrogen demands has been studied comparing the centralized green hydrogen production and distribution via trucks, against the installation of an on-site green hydrogen production plant made up of renewable power generation, an electricity storage system, and an electrolyzer. The problem was modeled and solved as a MILP optimization in MATLAB environment. Furthermore, a sensitivity analysis on the cost was carried out, which showed that even if the truck transportation cost for hydrogen is set at 0 a/kg, it is still more cost-effective to install an on-site electrolyzer to produce the required hydrogen.