By AYODEJI OKUNLOLA, Corresponding Author: AMIT KUMAR, Department of Mechanical Engineering, 10-263 Donadeo Innovation Centre for Engineering, University of Alberta
Right now, the world is interested in developing new energy pathways and technologies that will aid in meaningful climate change mitigation compatible with the United Nations Intergovernmental Panel on Climate Change’s 1.5° C objective (IPCC). In the context of energy, hydrogen (H2) is a gaseous fuel and energy carrier with the potential to aid in the transition to a low-carbon economy through its usage in currently high emissions-emitting activities. Hydrogen has the advantage of not generating carbon at the moment of burning and of being able to be stored for long periods; it may be utilized in applications that now use fossil-based gaseous fuels, such as ammonia production, oil sand mining, and heavy-heating industries (cement production and iron smelting). According to the International Energy Agency (IEA), the worldwide chemical and high-temperature heat industries alone could need more than 78 million tonnes (Mt) of hydrogen by 2070. The IEA further observes that hydrogen is well-suited for seasonal energy storage in power sectors that rely on variable renewable energy (RE) sources, particularly wind and solar energy. However, meeting the predicted long-term growth in global hydrogen consumption with emissions-free production methods will be difficult without significantly increasing production capacity. This is because, unlike other primary fuels utilized in the energy industry, hydrogen cannot be obtained naturally and must be separated from other molecules, primarily hydrocarbons and water.
Over the years, hydrogen has been mostly produced from fossil fuel feedstock, particularly natural gas and coal. Over 98 percent of global hydrogen production comes from techniques that use fossil fuels in the mining sector. However, there is an increasing global interest in producing hydrogen via low-emissions alternatives such as renewable energy-based (RE-based) water electrolysis (referred to as electrolytic hydrogen). Hydrogen production by wind- or solar-powered water electrolysis is seen as a favourable medium- and long-term sustainable production technique for the global hydrogen industry due to its lower environmental imprint when compared to other lower-emissions production methods. As a result, in the transition to a cleaner hydrogen economy, any country or jurisdiction that intends to leverage the energy carrier’s multi-sectoral capacities should clearly understand the production potential from either electrolytic hydrogen production pathway.
Among possible hydrogen production paths globally, wind-based electrolytic hydrogen generation has the lowest emissions footprint. The graphic (Fig A) below is a typical illustration of a system producing hydrogen by electrolysis of water with wind energy. The system consists of a wind power plant (with wind turbines, a control unit for voltage control, a rectifier) and an electrolyzer. The wind turbine generates alternating current (AC) which is then converted to direct current by the rectifier. Through electrochemical reactions, direct current (DC) is transmitted between two electrodes submerged in an electrolyte to divide water into its constituent elements of hydrogen (gas) and oxygen (gas), at the cathode and anode, respectively. One kilogramme (1 kg) of hydrogen requires approximately 54 kilowatt-hours (kWh) of electricity generated by a wind power plant.
A recent study conducted at the University of Alberta’s Department of Mechanical Engineering on the technical potential available to generate hydrogen from the wind-based electrolytic process across Canada found that approximately 1,897 million metric tonnes of hydrogen per year (Mt H2/year) can be produced in the country assuming 100% of the suitable land area is used: this is more than seven times the global hydrogen demand in 2019. Northern Canada had the highest wind-based hydrogen potentials, rather than southern Canada, owing to high wind speeds and a huge usable landmass. However, due to challenges related to the lack of extended infrastructure, particularly pipelines, to transport the gaseous hydrogen produced in the Northern Quebec, Newfoundland and Labrador, and the Territories, the Canada-wide exploitable wind-based hydrogen potential drops by more than 80% to approximately 364 Mt H2/year. Alberta, Saskatchewan, Manitoba, British Columbia, and Ontario are better suited to facilitate local production and delivery of wind-based electrolytic hydrogen due to access to existing infrastructure (see Fig. B). With current equipment cost estimates, producing wind-based electrolytic hydrogen in high wind resource sites across Canada might cost between $4 and $9 per kg of hydrogen ($/kg H2), depending on the system size built. If the capital costs of wind turbines and electrolyzers fall by 50% in the future, the production cost could fall to $3/kg H2.
As stated in Canada’s Hydrogen Strategy, achieving net-zero emissions by 2050 will necessitate the long-term deployment of renewable energy-based hydrogen production, particularly wind-based electrolysis. As a result, providing supportive regulatory policies and financial incentives that ensure significant capital infusion for commercial deployment of the technology and supporting enabling infrastructure, particularly pipelines, is critical for industrial adoption, economies of scale, and cost reduction of wind-based electrolytic hydrogen.
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Originally published in Scovan’s IGNITE Vol. 4