Early adoption of Hydrogen in the Orkney Islands
By Dr Beniot Couraud
The Orkney Islands, situated off the north eastern coast of Scotland, have been the site of numerous hydrogen projects over the past few decades. This is largely due to Orkney’s leadership in utilizing renewable energy sources, particularly wind, tidal, and wave power. However, a portion of this renewable electricity production must be curtailed because of constraints in the electric grid. Therefore, hydrogen is viewed as a key solution to reclaim the value of this curtailed electricity.
To tackle renewable curtailment issues, various measures have been put in place, such as reactive power injection and Active Network Management, while other methods are still under exploration. Efforts to upgrade the grid infrastructure are ongoing, including the potential installation of new cables to boost export capacity. However, the high investment costs have delayed these initiatives. Consequently, innovative strategies like Demand Side Management and energy storage systems are being tested to better balance local energy supply and demand.
In Orkney, hydrogen solutions are designed to mitigate grid constraints by producing hydrogen when there is an excess of renewable energy. Several projects have already been implemented, including SHyLO (Solid Hydrogen at Low Pressures, which aims to demonstrate the effectiveness of utility-scale solid-state green hydrogen storage), ITEG (Integrating Tidal Energy and Hydrogen), HyDIME (Hydrogen as fuel in Marine transport), BIG HIT, SURF ‘N’ TURF, DUAL Ports, HySeas III, and ReFLEX. These projects leverage two main initiatives:
First, on the island of Shapinsay, excess generation from a community wind turbine is used to produce green hydrogen through a 1MW Proton Exchange Membrane (PEM) electrolyser. The hydrogen is stored either locally in a 30kg storage facility for heating at Shapinsay School with a 30kW boiler or in special mobile units that are transported to Kirkwall. In Kirkwall, it is stored in the 110kg hydrogen storage facility at the Refuelling Station in Hatston, where it can be used to power the harbour and ferry operations.
Second, on the island of Eday, excess generation from a 900kW community wind turbine and a tidal turbine test site is used to produce hydrogen through a 0.5MW Proton Exchange Membrane (PEM) electrolyser unit. The hydrogen is stored in high-pressure tube trailers and transported to the mainland using a fleet of semi-trailers that can carry hydrogen via road or ferry. This hydrogen can be used and stored in the 75kW fuel cell (3x25kW) at Kirkwall harbour, which powers ships at port, or in the 110kg hydrogen storage at the Hydrogen Hatston refuelling station for the council’s fleet of Symbio hydrogen electric vans being trialed in Orkney (fuel cell with battery).
Therefore, the early adoption of hydrogen in the Orkney Islands has led to two significant projects that serve as valuable case studies for Hi-Act. These projects illustrate how hydrogen can be integrated into energy systems with high renewable energy production and provide concrete examples of the enablers and barriers to hydrogen adoption.
For instance, the Big HIT project revealed that hydrogen production is currently constrained by the low consumption of hydrogen on the islands and by the limited amount of curtailed energy available to power electrolysers at low cost. This limitation prevents electrolysers from operating at their full capacity (producing 30 tonnes per year versus a theoretical maximum of 180 tonnes per year), thus hindering profitability.
Although electricity prices for hydrogen are very low in Shapinsay and Eday due to the use of curtailed electricity, hydrogen remains less economically attractive than conventional fuels for heating and combined heat and power (CHP) applications. This is because of the limited use of electrolysers and the costs associated with hydrogen storage and transportation via dedicated mobile storage units. Indeed, the absence of a gas network on the islands adds an extra cost of approximately £3 per kilogram to store and transport green hydrogen, making its production less beneficial and not as competitive as other existing fuels.
In contrast, for transportation, hydrogen shows a similar economic value to standard fuels, though this may not be the case in other locations where electricity prices to power electrolysers would be higher. This underscores the importance of techno-economic analysis when integrating hydrogen into a smart local energy system and highlights the need for careful arbitrage in the use of cheap electricity.
These issues are being addressed within Hi-Act, as we aim to develop a methodology for identifying energy systems that can successfully integrate hydrogen. We are also exploring innovative methods involving multi-agent systems, smart cyber-physical systems, and local markets to help smart local energy systems derive sustainable value from local hydrogen production and consumption.
