Council is making a splash using hydrogen as a new marine fuel
IN 2018 Orkney Island Council and its partners received a £400,000 grant from Innovate UK to launch the HIDIME project.
This involved working through the challenges of injecting hydrogen into a diesel marine engine, on Orkney Ferries' MV Shapinsay.
In the latest milestone, the ship's crew of five successfully completed a second course, this time on working with hydrogen, including how to fight a hydrogen fire (hydrogen fires are almost invisible to the naked eye).
In 2020 the crew passed a course on the handling and storage of hydrogen.
Both courses were devised by Orkney College UHI'S maritime studies department in collaboration with Orkney Ferries and the European Marine Energy Centre (EMEC).
The whole HIDIME project is something of a proof of concept and builds on the significant amount of research into hydrogen injection in diesel marine engines.
There are some significant challenges for engineers when it comes to blending hydrogen and diesel.
A certain amount of hydrogen injected into diesel fuel improves the thermal efficiency of the fuel, but there are also heat and volume pressure issues.
Nevertheless, there is an everincreasing number of projects on zeroemission vessels (ZEVS) around the world, either already in full swing or getting started. Orkney's hydrogen safety courses are already attracting attention from other countries.
The European Marine Energy Centre's electrolyser on the island of Eday has played a key role in the HIDIME project.
It was initially powered by tidal turbines at EMEC'S marine test site and is also optionally fed from the community-owned wind turbine on Eday.
Control switchgear inside EMEC'S substation determines whether the power fed to the electrolyser is to be routed from the tidal generators being tested at EMEC'S Fall of Warness site or the community wind turbine.
The electrolyser is housed in a standard 20 by 10 ISO container and can generate up to 220 kg of high purity, fuel cell grade hydrogen per day.
Hydrogen gas is produced via electrolysis at 20 bar which is then passed into a compressor to further pressurise the gas to 200 bar at which point it is stored.
Up to 500 kg of hydrogen can be stored in storage cylinders on site.
The hydrogen can then be transferred to specially designed mobile storage units (MSUS) and transported to the Orkney mainland by road and ferry.
Each MSU can transport 250 kg of hydrogen. The MSUS consist of 59 lightweight composite cylinders made of aluminium with a Kevlar wrap, specially designed to comply with road restrictions.
The hydrogen can then be used locally in a variety of fuel, power and heat applications in hydrogen technology projects.