turbine eoliche offshore

Wind and Hydrogen, a win win pair

How offshore wind will team up with hydrogen to provide power.

by Adam Kimmel
21 September 2021
5 min read
by Adam Kimmel
21 September 2021
5 min read

One of the most significant challenges critics of renewable energy cite is the lack of consistency in its energy supply —for example, a lower supply of solar energy when the sun isn't shining, or less wind power when it's calm outdoors.

Hydrogen, however, is an energy carrier that is unaffected by the time of day, the weather, or any other environmental factor. It is energy-dense relative to its volume, does not contain carbon, and exists naturally as an element in water. Despite these benefits, its production cost continues to be a challenge for the wide-scale distribution of hydrogen power, and splitting water molecules is energy-intensive.

The cost of oil is lower than the cost of hydrogen. Today, hydrogen costs between €2.05 - €5.58/kg ($2.50 - $6.80/kg) to produce, while a kilogram of hydrogen has the energy equivalence of a gallon of oil (3,8 kg of oil), which as of June costed around $1.67 per gallon.

As long as that differential exists, the hydrogen industry may struggle to gain wider adoption.

Two of the most common hydrogen production methods —steam-methane reforming (SMR) and electricity-consuming electrolysis— each have at least one, if not more fundamental flaws. SMR is sustainable, although not renewable because the chemical energy used to make hydrogen comes from fossil fuels. Electrolysis is renewable if the electricity required to split water molecules comes from a natural, carbon-free source, like wind or solar.

Because these approaches are flawed when implemented alone, combining them may well be the best path to create renewable, consistent, cost-efficient power.

From the efficiency perspective, direct electrification is preferable but not easily exploitable in all areas. In some energy-intensive sectors, such as the steel industry, long-haul aviation, and maritime shipping, the role of green hydrogen will therefore be significant.

Offshore wind as a medium to help make green hydrogen

The most significant drawbacks to wind energy are the variability of the energy it produces and a low energy conversion efficiency of between 30 to 45%. One way to mitigate the variability of wind energy is to use offshore wind which offer a stronger and more consistent energy supply. With 40% of the global population living within 100 km of a coast, the wind power generated offshore does not need to be transported very far. In the US, offshore wind could provide over 2,000 gigawatts of capacity, enough to power 1.5 billion homes for a year, assuming an average energy consumption of 10,650 kWh/year. There is ongoing work in the EU so it can reach 100 gigawatts by 2030 and 300 gigawatts by 2050. As of 2020, the EU already had 25 gigawatts online.

Offshore wind aids in delivering consistent distributed power by providing an infinite, free energy source that offers electrolyzers the electricity they need to split water molecules, which is necessary for the production of hydrogen energy. In addition, a floating wind turbine market has emerged to leverage the faster wind speeds found even further offshore, minimizing transport and conversion losses and operating independently of the electrical grid.

How can wind enable electrolysis?

Although electrolysis requires an intensive amount of input energy, using wind to power hydrogen production would be clean and efficient.  Around 450 gigawatts of offshore wind energy could produce 24 billion kg/year of hydrogen, enough to power around 74 million homes in a year (90 GW).

By providing the energy needed to make hydrogen, wind energy increases its efficiency via conversion to a mobile, energy-dense carrier. In addition, shifts in global oceanic and atmospheric conditions are increasing average wind speed by over 7% since 2010. This pattern, tied to an increase in atmospheric energy and temperature, could enable wind farms to generate 37% more power in the next few years without changing the current infrastructure.

Towards a new economy

Electrolyzers have historically been a limiting technology in delivering green hydrogen. They carry significant capital costs and require massive energy input to split water to release hydrogen gas. Combining the benefits of offshore wind with the advantages of hydrogen enables a renewable path to the hydrogen economy. Distributing hydrogen is the next hurdle to clear, though work is happening to utilize existing pipelines and transportation/storage vessels that would, however, need major interventions to become compatible with hydrogen transportation. 

Lower electrolyzer and offshore wind costs will move hydrogen much closer to a commercial reality for distributed power by the end of the decade.

The author: Adam Kimmel

A practicing engineer, R&D manager, and engineering writer, with degrees in Chemical and Mechanical Engineering. He is the founder and Principal at ASK Consulting Solutions, LLC, an engineering and technology content writing firm.