Dear Colleagues,

Hydrogen is undoubtedly one of the most promising future energy sources which is versatile in nature and can introduce deep decarbonisation among the industry and energy sectors. With a high energy density (120-142 MJ/kg), it produces energy with zero climate-warming emissions. In an era when energy industries are contributing around 33.2 Gt-CO_2­ emissions per year, it is hydrogen energy which can play a major role to mitigate the emissions and provide a positive shift towards decarbonisation.

Hydrogen can be produced in different pathways, including gasification of carbonaceous fuels, steam methane reforming (SMR), electrolysis, liquid fuel reforming etc. However, 76% of the 70 MMT of the current global generation of hydrogen comes from SMR of natural gas, whereas 22% comes through coal gasification and only 2% via electrolysis. According to USDOE, hydrogen generation through SMR of natural gas or gasification of coal/biomass/waste plastic etc. cost around $1.43/kg to $2.27/kg, including carbon capture and storage. In comparison, generation through electrolysis at a centralised station is estimated to be $5/kg, which multiplies three to four times if zero-carbon electricity is used. Given the maturity and substantial economic advantage of methane reforming or gasification, it is evident that they will be the cheapest route of industry-scale hydrogen production for the foreseeable future. Since carbon emission from hydrogen production depends on the primary energy source and the process exploited, it is needless to say that a continuous scientific effort is required in order to achieve carbon neutral and low-cost production of hydrogen. In addition to hydrogen production, cost-effective and safe storage/transportation of hydrogen have always been among the primary challenges to integrating hydrogen energy into the overall energy system. Low volumetric energy density and ability to permeate metal-based materials pose operational and safety constraints for hydrogen storage and transportation. It is evident that in the near future, large-scale hydrogen value chains will require a variety of storage options, which also calls for further research and development in this particular area.

Following increasing efforts to keep global warming to a minimum of 2⁰C, it is anticipated that the global demand for hydrogen will increase to 78 exajoules by 2050. According to IEA, clean hydrogen is experiencing unprecedented political and business momentum right now since it has been understood that hydrogen is the way of tackling environmental concerns without affecting energy security. Hence, we invite researchers around the globe to contribute to this special issue and share their ideas, innovation, knowledge and experience towards the progress of hydrogen generation and utilisation. Both technical and review/analytical articles are welcome.

Dr. Shahabuddin Ahmmad
Prof. Dr. Fares Abedalwally Ogleh AlMomani
Dr. Imtenan Sayeed
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• Hydrogen generation
• Transportation
• Storage
• Coal and Biomass gasification
• Steam methane reforming
• Electrolysis
• Carbon capture and storage
• Life cycle assessment
• Fuel cell
• Techno-economic analysis