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How will green hydrogen play a key role in our future?

Sandra O'Connell asks David Macartney, corporate development manager of Energia

What is hydrogen?

Hydrogen is a versatile, clean and safe energy carrier that can be used as fuel for power or in industry as feedstock. Importantly, hydrogen produces zero emissions at point of use. Hydrogen can be stored and transported at high energy density in liquid or gaseous form. Hydrogen can be combusted or used in fuel cells to generate heat and electricity.

Is it safe?

Over the past decades hydrogen has been widely used in industry, ensuring safe production, storage, transport and utilisation. In Ireland, it has been used in the power and pharma industries and has been produced by BOC in Dublin. Hydrogen is a flammable fuel and has similar flammable properties to gasoline and natural gas. Hence, similar to other flammable fuels, hydrogen can be used safely when simple guidelines are observed and the consumer has knowledge of its characteristics.

What role might hydrogen play in terms of meeting our future energy needs?

Green hydrogen (produced from renewable electricity) will play an important role in the decarbonisation of the economy. Our future energy needs will be met increasingly by renewable electricity, however some energy end uses are hard to electrify via the grid or with batteries, especially in transport but also in other sectors.

Hydrogen also represents an optimal overall solution for long-term, carbon-free seasonal storage. While batteries, super-capacitors and compressed air can also support balancing, they lack either the power capacity or the storage time span needed to address seasonal imbalances. Ireland’s electricity generators also have fuel security obligations to store oil in case the gas supply is interrupted. As Ireland transitions towards net zero emissions, these secondary fuel requirements will need to be reviewed and hydrogen could play a role.


With increasing levels of constraint or curtailment of renewable electricity generation – such as available renewable generation that the grid is unable to utilise – this energy could be used to produce renewable hydrogen either for injection into the gas grid or for transport to other end users.

What hydrogen projects has Energia been working on?

Energia Group has led the introduction of hydrogen buses on the Island of Ireland. Over the last eight years, Energia has secured EU funding for a 1MW electrolyser (the equipment that splits water into its constituent elements: oxygen and hydrogen), which is in construction at Energia’s Long Mountain wind farm in Co Antrim. It has also secured funding from the UK department of transport to underpin Translink’s purchase of three hydrogen double-decker buses, which are now in operation, and also to support the installation of the island’s first hydrogen fuelling station, owned by Energia, which is now operational in Belfast.

As bus operators move from the trial phase they will need to consider multiple sources of hydrogen supply to manage electrolyser maintenance and failure. This contingency planning is very familiar with operators in the electricity sector. The transition to public transport using indigenous energy (such as hydrogen produced from wind or solar) will mitigate against the volatility of international commodity (gas and oil) prices and also improve security of supply.

Energia Group has recently won circa £400,000 (€470,000) funding from the UK department of transport to undertake a feasibility study to enable zero-emission maritime solutions at ports and harbours in Northern Ireland. Energia is leading the consortium which includes Belfast Harbour, NIE Networks, Mott MacDonald, University of Ulster, Queen’s University Belfast and Artemis.

The work with Artemis is very exciting as it is developing a zero-emission hydrofoil ferry which will be built in Belfast and we are investigating the use of hydrogen on this ferry. Energia Group also believes there is an opportunity to inject hydrogen into the gas network and we are investigating options to produce hydrogen from curtailed electricity at our wind farms to supply to our gas customers, which could include the supply of green hydrogen to Energia’s power plants.

Energia Group is taking part in Cop26 in Glasgow to highlight the NI Green Seas study funding and the work of the wider Belfast Maritime Consortium.

Sandra O'Connell

Sandra O'Connell

Sandra O'Connell is a contributor to The Irish Times