The low carbon hydrogen economy of the future has been off to a slow start, but signs of a rapid acceleration are beginning to emerge. In the latest set of developments, the US Air Force is touting a zero emission renewable hydrogen fuel cell bus as a step toward additional Department of Defense applications, Canada is dropping hints that it would like to be the first country in the world with a full size hydrogen fuel cell passenger train, and the auto world is buzzing about Hyundai's new Nexo fuel cell electric crossover SUV.

Welcome to the renewable hydrogen world

If you caught that thing about the Air Force and renewable hydrogen, that's the key to the whole thing. Hydrogen is an abundant, zero emission fuel but it does not exist naturally in a usable state. It must be extracted from something else, and right now that something is primarily fossil natural gas.

The natural gas angle explains why the dream of a low-carbon economy powered by hydrogen has long been dismissed as a kind of sustainability oxymoron.

Fortunately for hydrogen fans, the picture has changed dramatically in just the last few years with the advent of low-cost solar and wind energy.

Low cost renewable energy means that electricity is freed from fossil fuel sources. That opens up the potential for using an electrical current (aka electrolysis) to produce renewable hydrogen by "splitting" water.

Renewable hydrogen from biogas is another sustainable option, but right now it seems that most of the R&D attention is going to water-splitting.

As for why bother producing hydrogen from water when you already have wind and solar energy generating whatever power you need, that's a good question.

One answer is that hydrogen provides another energy storage option that helps ensure 24/7 power for wind and solar.

Transportation is another angle. Hydrogen can transported with existing pipelines, which could help reduce or eliminate the need for new pipelines and power lines.

It can also be packed into containers and shipped by road. That expands the use options into remote areas where the construction of new pipelines and power lines is not feasible.

Finally, hydrogen fuel cells may provide greater range and more muscle when used in vehicles, compared to batteries. That's why fuel cells have been popping up in buses and trains as well as military vehicles, long haul trucks and SUVs.

Buses...

Hawaii is one of several US states with comprehensive programs aimed at growing the hydrogen economy. The Air Force has been exploring fuel cells there in support of the state's 100% renewable energy goals.

In the latest news, the Air Force is using a fuel cell electric bus to ferry up to 25 passengers around Joint Base Pearl Harbor-Hickam. The demonstration-scale project is designed to showcase how hydrogen and fuel cell technology can be applied to the Department of Defense.

The project actually dates back to 2006, when it began with a focus on demonstrating hydrogen compression, storage and dispensing. In 2010 it was revamped to focus more strongly on vehicles, including the use of hydrogen in internal combustion engines as well as fuel cells (fuel cells produce generate electricity through a reaction between hydrogen and oxygen).

Among the hydrogen vehicles involved in the project are an MJ-1E fighter weapons loader and a U-30 aircraft tug.

Here's the Air Force explaining the benefits of hydrogen in terms of wind and solar grid integration:

In a hydrogen electrolysis unit, water is separated into hydrogen and oxygen using electricity. This hydrogen is collected, compressed and stored for fuel while the oxygen is either released into the air or can be collected and used in other applications. In many cases, excess electricity created during peak production by other renewable sources, such as wind and solar, can be used in this process to reduce cost and provide nearly emission-free fuel for the fuel cells. The collected hydrogen can then be used in hydrogen fuel cells to create electricity as needed...

Trains...

Transportation planners have been taking a close look at fuel cells to replace diesel locomotives, and it seems that Canada may be positioning itself for a front-running position in that race.

Last week, Ontario announced that has engaged the global firms Alstom and Siemens in a new fuel cell initiative aimed at a major expansion and electrification of its GO Transit service. Both companies are already involved in fuel cell train projects elsewhere on the globe.

The use of fuel cells would enable the system to grow without the need for conventional overhead wires. That represents an infrastructure savings in areas that could be wired, and it would also enable transit to reach areas where overhead wires are not feasible.

As with the Air Force, Ontario officials are interested in developing the new "hydrail" system in tandem with renewable hydrogen produced by water-splitting, preferably with wind or solar energy.

Speaking of feasible, right now the initiative is in the study phase. That would seem to put Ontario behind the pack in the race to put the first fuel cell locomotives in service globally. However, the next-most advanced project is an initiative in Germany that involves much smaller trains. If all goes well, Go Transit could still lay claim to the first hydrogen fuel cell double-decker carriages.

...and automobiles

In the passenger car sector, fuel cell electric vehicles have been slow to catch on. High costs and the lack of hydrogen fuel stations are two factors turning off consumers. However, similar factors -- high cost and lack of charging stations -- were once cited frequently by critics of battery electric vehicles. Auto manufacturers have not been deterred by the nay-saying over battery EVs, and it seems they are similarly committed to developing fuel cell EVs.

Hyundai's new fuel cell Nexo represents another big step forward. Rather than jury-rigging fuel cell technology onto a conventional design, Hyundai invested some big bucks in developing its own dedicated fuel cell platform.

So far it looks like the gamble has paid off, as it seems that the fuel cell car has been well received by auto enthusiasts. Here's a sample from Car Magazine:

...hydrogen electric probably is the power source of the future. It makes a great case for itself in the Nexo, with zero tailpipe emissions (though we’re not quite there with well-to-wheel sustainable energy part yet…), a theoretical maximum range of 370 miles between trips to those admittedly hen’s-teeth hydrogen filling stations, and the facility to scrub particulates from the air as you drive.

That’s right. The Nexo actually cleans the ambient environment around the car, removing dust and other minute airborne pollution along the way. It emits just clean air. But then so did the ix35… just nowhere near as efficiently. And Hyundai has crammed this latest fuel cell arrangement into roughly the same size and weight as a larger internal combustion engine, so it’s scaleable too...

The NEXO model will spearhead Hyundai Motor’s plans to accelerate development of low emission vehicles. Hyundai Motor Group plans to introduce 38 eco-friendly models by 2025 and Hyundai Motor Company plans to introduce 18 models by 2025. This new development roadmap also represents the next step for Hyundai Motor toward realizing the ultimate ambition of creating a cleaner environment through eco-friendly vehicles.

Trucks and airplanes, too

Triple Pundit has been covering fuel cell EVs for the past several years, and this is the first time someone has introduced the idea that a car could actually clean the air as it goes. Car Magazine hammers home that point:Hyundai seems is already counting on Nexo to represent its entire lineup of low and zero-emission vehicles as its "technological flagship." Here's the company enthusing over its new low carbon identification:Nexo goes on sale in the US later this year, so now would be a good time to check out the location of hydrogen fuel stations in your area.Last week's hydrogen fuel cell news was pretty impressive, and that's not all. Fuel cells are also beginning to make inroads into other transportation modes.

The electric truck startup Nikola, for example, seems confident that its new fuel cell electric long-haul semi truck can go head to head against Elon Musk's new Tesla battery-powered truck.

In the logistics arena, fuel cell forklifts are already beginning to compete against their battery-powered cousins for zero emission operations. That's a critical need for warehouses and seaports, where reducing carbon emissions is a priority.

UPS is also looking to introduce fuel cells into the delivery truck field, with an eye toward improving its carbon footprint in key urban areas.

Photo (cropped): Nexo via Hyundai.