Green hydrogen is an up-and-coming replacement for fossil fuels that advocates claim fits the bill for sustainability. On paper, it certainly looks promising. Renewable power sources? Check. No carbon emissions for hydrogen fuel cells? Check. Unfortunately, adopting green hydrogen still presents several challenges. This roundup looks at the biggest ones.
Hydrogen Fuel Is Volatile and Potentially Dangerous
Every combustible fuel source is potentially dangerous, and no form of hydrogen is exempt. The main factor governing fuel safety is the ability to separate the three major components of fire. These are an ignition source like sparks or excessive heat, an oxidizer like air, and sufficient fuel. While hydrogen is safer than alternatives in some cases, it requires more extensive safety protocols
in others.
Hydrogen can ignite more readily than gasoline or natural gas due to its wider range of flammable oxygen concentrations and lower ignition threshold. Therefore, proper ventilation and fault detection are crucial to creating safe hydrogen systems. In addition, special flame detectors are necessary because hydrogen ignites with an almost invisible flame.
Additionally, some metals react with hydrogen and become more prone to cracking. Therefore, finding suitable materials is essential to developing secure hydrogen frameworks. All of these considerations contribute to the price of green hydrogen.
Green Hydrogen Is Expensive
In the US, hydrogen from fossil fuel energy costs around $1.50/kilogram, whereas green hydrogen is roughly double. Fortunately, green hydrogen might become cost-competitive by 2030, according to three sets of experts at McKinsey, BloombergNEF, and Wood Mackenzie.
They believe economies of scale will eventually drop the price of electrolyzers while wind and solar electricity prices continue to plummet. While this is undoubtedly true, industry is pushing back against the high investment costs of green hydrogen infrastructure, and it is unclear whether the 2030 estimate is accurate.
Most Storage Relies on Large Volume Tanks
Hydrogen may have a high energy density, but it has a very low overall density. As one of the most rarified gases, hydrogen storage is a considerable challenge for large stationary facilities and smaller fuel tanks. Current storage alternatives often need large-volume devices that retain hydrogen in gas form. Footprint is less of a problem in industrial applications with plenty of room. However, bulky hydrogen storage may not be possible when space is at a premium.
In addition, fuel-cell cars need enough hydrogen to give a driving distance in excess of 300 miles to be practical. Moreover, users must be able to recharge the vehicle swiftly and efficiently. While several smaller hydrogen fuel cell electric cars (FCEVs) with this range are available, these FCEVs depend on internal storage mechanisms capable of very high pressures. These come at a price. Large storage volumes may be less of an issue for bigger cars, but supplying enough hydrogen capacity across all makes and models of private vehicles remains a concern.
There Is No Real-World Data on Large Scale Infrastructure
Green hydrogen looks very promising for domestic heating use. However, the technology to employ a society-wide hydrogen fuel infrastructure has never been tested, and obstacles may remain. For example, while some existing natural gas pipelines may be able to accommodate hydrogen, we don't know how long they will last without upgrades. Furthermore, the amount that will require immediate service is unknown.
We must evaluate the technology to begin utilizing hydrogen. As a result, hydrogen experiments are underway in several European nations. The UK government has said that a neighborhood trial would occur by 2023, a big hydrogen village, and maybe a town pilot by 2030.
Burning Hydrogen Emits GHGs in the Right Circumstances
Green hydrogen is a promising alternative in many ways, mainly because it is so clean. Unfortunately, there is a dirty secret. In fuel cells, hydrogen does indeed produce only water vapor and heat. However, other engines and boilers do not operate on the same chemical process as a fuel cell. In some models, the temperature, pressure, and flame size can cause nitrous oxide (N2O) emissions. This toxic pollutant could have a massive impact on the urban poor and other disadvantaged communities due to its substantial global warming potential.
Key Takeaways
- Stay Involved – The price of most sustainable initiatives starts high. However, as we have seen from recent drops in the price of some renewables, incentives, and demand are potent forces. So do what you can to support organizations and politicians who contribute positively.
- Pay it Forward – Finding an energy source with no drawbacks is challenging. Nevertheless, renewable power is the best bet for combating climate change. This particularly helps communities that have traditionally struggled. So do what you can to leave behind fossil fuels.
- Follow the Fuel Cells – A surprising number of American retailers and supermarkets have embraced hydrogen fuel at their storefronts and warehouses. Consider supporting them.
