Vetyajoneuvot saattavat edustaa tulevaisuuden liikennettä – Onko niissä turvallisuushuolia?

Vetyajoneuvot tai vetyvoimalla toimivat polttokennoajoneuvot ovat nousseet ilmiöksi vuodesta 2015 lähtien. Vaikka on liian aikaista ennustaa vetyajoneuvojen tulevaisuutta, on kiistaton, että kiinnostus niihin on ollut havaittavaa, mutta vaihtelevaa. 

Vuosina 2022–2023 vetyvoimalla toimivien polttokenno‑sähköajoneuvojen määrä laski 20 704:sta 14 451:een. Vuosittainen lasku ei riitä muodostamaan trendiä kuluttajien kiinnostuksessa vetyajoneuvoihin. Keskustelua on kuitenkin molemmilla puolilla. Vaikka vetyajoneuvoilla on monia etuja, niiden turvallisuudesta käydään myös runsaasti keskustelua. Seuraavissa osioissa tarkastelemme näitä kahta vetyajoneuvojen näkökulmaa. 

Vetyajoneuvojen ainutlaatuisuus

Vaikka ne ovat sähköajoneuvoja, vetyajoneuvoille ei tarvita sisäänrakennettuja akkuja. Niissä on oma voimalaitos, joka pystyy muuntamaan polttoainesäiliön vedyn sähköksi. Vetyautot kulkevat nollapäästöisillä paikallisilla päästöillä. 

Kuitenkin suurin tähän mennessä tarjottava etu on lyhyt tankkausaika. Toisin kuin muut sähköajoneuvot, vetyajoneuvojen tankkaus ei riipu ajoneuvon mallista tai infrastruktuurista. Niillä on pitkä energian varastointikapasiteetti, eikä niiden toimintasäde ole riippuvainen ulkolämpötilasta, mikä poistaa kylmässä säässä tapahtuvan suorituskyvyn heikkenemisen. 

Vety on myös erittäin tehokas tapa varastoida ja kuljettaa uusiutuvaa energiaa, ja sen käyttöönotto auttaa vähentämään kustannuksia pitkällä aikavälillä. 

Vaikka hyödyt ovat kaikille nähtävissä, jotkut tutkimukset osoittavat myös vetyajoneuvojen riskin ja vahinkopotentiaalin. Tarkastelemme tänään tapausta, jossa TU Grazin tiimi on analysoinut vetyajoneuvojen riskin ja vahinkopotentiaalin tunneleissa. Tutkimus on myös esittänyt suosituksia. 

Vetyajoneuvojen riskit ja vahinkopotentiaali: Kuinka minimoida riskit

Under its HyTRA project, the Graz University of Technology has investigated several aspects that could prove risky. The study assessed possible incident types, dangers to people, and the tunnel structure and recommended measures that could be taken to minimize these risks.

While researchers have determined that the probability of accidents involving hydrogen-powered vehicles in a tunnel is low, the high energy density of hydrogen and its substantial storage pressure render these FCEVs powered by hydrogen a significant risk for extensive damage.

The storage of hydrogen in car tanks at a pressure of 700 bar could lead to the rapid release of a great deal of energy. If ignited, the hydrogen might burn at temperatures over 2000 degrees Celsius. Manufacturers design the fuel tanks to be sturdy and well-protected against mechanical impact; however, they fall short in situations such as rear-end collisions with large trucks.

There are broadly three hazardous scenarios that might evolve as the outcome of such a collision.

In the first case, the thermal pressure relief device (TPRD) might activate when pressure increases due to a thermal impact, releasing hydrogen from the tank in a controlled jet. This mechanism helps sustain the pressure at a safe level, preventing the tank from rupturing. However, this can still pose a danger if the discharged hydrogen mixes with air and ignites. Nonetheless, the danger zone would remain confined.

This scenario worsens if the Thermal Pressure Relief Device fails, potentially leading to the tank exploding. The resulting blast wave could spread throughout the entire channel. The risk of death would extend up to approximately 30 meters, while the likelihood of serious internal injuries extends up to 300 meters. Further away, there still exists the risk of ruptured eardrums.

In the third scenario, the least likely of all, hydrogen is first released without igniting. Being the lightest element in the periodic table, the gas rises and accumulates as a cloud under the tunnel ceiling. If an ignition source, such as hot lamps or an electrical impulse, is present, it might trigger a hydrogen cloud explosion, generating a significant blast wave.

The risk scenario investigators proposed a host of mitigating strategies. The team suggested implementing stricter speed limits, monitored through section control. They also advised precise distance control strategies, supported by a robust signaling mechanism to alert drivers when they were following too closely.

While discussing the risks and damage potential of hydrogen vehicles, the TU Graz team did not forget to mention the context in which they operate and how their risk and damage potential are measured.

“Modernit vety‑säiliöt on rakennettu niin turvallisesti, että paljon on mentävä pieleen, jotta vety pääsee karkuun.”

– Daniel Fruhwirt, Termodynamiikan ja kestävien propulsiojärjestelmien instituutti, TU Graz

Vetyajoneuvojen edistäminen

Researchers predict a significant uptick in adoption of Hydrogen Vehicles in the coming years. Industry researchers and analysts estimate that the number of hydrogen vehicles in service globally will exceed one million in 2027, up from just over 60,000 in 2022, representing a surge of more than 1,500%. The consumer market is expected to be the leading segment in the Hydrogen Vehicles space, accounting for more than 60% by 2027.

There are government initiatives in place that promote fuel‑cell vehicles. For instance, the Office of Energy Efficiency and Renewable Energy, a unit under the Department of Energy, launched H2USA in 2013. In their official statement, the government authorities had the following to say about H2USA’s mission: 

“H2USA’s mission is to promote the introduction and widespread adoption of fuel cell electric vehicles across America. Members include federal agencies, the fuel cell trade association, automakers, hydrogen providers, fuel cell developers, national laboratories, and additional stakeholders. The collaboration provides a platform for the United States similar to the public‑private collaborations in other countries focused on hydrogen, particularly Germany, Japan, and the UK.”

Reportedly, H2USA has more than 30 participants now. 

Apart from government initiatives, there are many performance‑enhancement research underway that help build interest and trust among potential consumers for hydrogen fuel cell vehicles. 

For instance, a recent study conducted by a team of researchers from Harvard and Incheon National University devised an approach to build fuel cells that score high in both the aspects of durability and lifespan. The study revolved around developing a category of fatigue‑resistant electrolyte membranes consisting of an interpenetrating network of Nafion and perfluoropolyether (PFPE). The team noted a slight degradation in the fuel cell’s performance in exchange for a ‘hämmästyttävä parannus kestävyydessä/käyttöiässä.’

Another exciting development that has been particularly encouraging for the manufacturers is the introduction of specialized enzymes into depleted oil wells. These enzymes break down lingering hydrocarbons into various components, including hydrogen. This advancement might result in countless depleted and abandoned oil wells across the world turning into sources of a more sustainable fuel from their depths—hydrogen.

The push for hydrogen vehicles is in line with the vision of creating more sustainable transport alternatives for the future, potentially even more sustainable than electric vehicles (EVs). This is because EVs do not fully achieve sustainability; their emission potential depends on how the electricity is generated.

Many companies are developing hydrogen vehicle solutions, anticipating that governments and transport authorities will increasingly favor hydrogen vehicles over EVs in the future. In the following segments, we discuss a couple of such companies.

#1. Ultium-alusta ja HYDROTEC-polttokenno‑tehopalat General Motorsilta

The GM Hydrotec Fuel Cell Technology claims to be an affordable fuel cell power solution for land, air, and marine applications. In 2021, Wabtec Corporation (NYSE: WAB) and General Motors (GM ) (NYSE: GM) announced to collaborate on developing and commercializing GM’s Ultium battery technology and HYDROTEC hydrogen fuel cell systems for Wabtec locomotives.

While speaking about the value‑add GM’s solutions were to bring for Wabtec, the CEO and President of Wabtec, Rafael Santana, had the following to say:

“Our FLXdrive locomotive, the world’s first 100‑per cent battery‑powered locomotive, has proven its potential to slash carbon emissions by up to 30 percent when operating at 6 MWh. But we can’t stop there. By working with GM on Ultium battery and HYDROTEC hydrogen fuel cell technologies, we can accelerate the rail industry’s path to decarbonization and pathway to zero‑emission locomotives by leveraging these two important propulsion technologies.”

GM’s Hydrotec solution offers compact and easy‑to‑package fuel cell power cubes for a wide range of applications, including locomotives. Ultium is the battery technology that adds to the flexibility, efficiency, power, and reliability that rails need.

In 2021, General Motors also struck a collaboration with Liebherr‑Aerospace to develop a hydrogen fuel cell power generation demonstrator system for aircraft. Next year, GM decided to go beyond the space of vehicles and automotive transport with its Hydrotec solution.

The company declared its plans to develop multiple HYDROTEC‑based power generators powered by GM’s Generation 2 HYDROTEC fuel cell power cubes. These include:

• A Mobile Power Generator (MPG) that offers fast‑charge capabilities for EVs without installing permanent charge points.
• The EMPOWER rapid charger that allows retail fuel stations to add affordable DC fast charging without expanding the grid.
• A Palletized MPG to quietly and efficiently power military camps and installations.

Vuodelle 2023, GM raportoi liikevaihdoksi 171,8 miljardia dollaria, osakkeenomistajille kohdistuva nettotulos ylitti 10 miljardia dollaria ja EBIT‑säädetty 12 miljardia dollaria.

#2. Cellcentric: tasavertainen yhteistyö Daimlerin ja Volvon välillä

Cellcentric, a 50:50 joint venture between Volvo Group and Daimler Truck (DTG.DE ) AG, is aimed at becoming a leading global manufacturer of fuel cells to help the world achieve its target of introducing neutral and sustainable transportation by 2050.

In toukokuu 2024, Cellcentric announced its NextGen fuel cell system, a solution customized for long‑haul trucks in Europe and North America. The system is a highly integrated, compact, and low‑weight single‑system package solution that can deliver power above 350 kW at its peak performance.

According to Cellcentric’s estimates, the solution is expected to offer consumption savings of 20 percent compared to the BZA150 generation. The NextGen system also boasts of a power density increase of 30 percent compared to the current generation and a 40 percent reduction in waste heat at peak load, owing to its sophisticated system design and optimal performance. The solution also lowers the cooling requirement, improving the levels of product fitness. 

Koko vuodelle 2023, Volvo nosti nettomyynninsä lähes 80 miljardia SEK:stä 553 miljardiin SEK:ä ja säädetyn liiketuloksen 77,6 miljardiin SEK (50,5), jolloin säädetty liiketulosprosentti oli 14,0 % (10,7). Daimler‑konsernin liikevaihto kasvoi 10 % saavuttaen ennätystason 55,9 miljardia euroa vuonna 2023.

Vety‑polttokennoajoneuvojen tulevaisuus

Kaiken kaikkiaan vetyajoneuvojen tulevaisuus näyttää lupaavalta, sillä globaali tarve kestäville liikenne­ratkaisuille on kasvussa. Kuitenkin valmistajien ja teknologiatutkijoiden on työstettävä vety‑polttokenno‑sähköauton kaikkia osa‑alueita, mukaan lukien solukasa, polttoaineen täyttö, polttoainesäiliö, ohjain ja lämpöjärjestelmä. 

Nämä ajoneuvot tarjoavat useita etuja, kuten välittömän väännön ja tasaisen, jatkuvan tehon, alhaiset huoltovaatimukset, nopean tankkauksen, nollapäästöt ja muuta. Kuitenkin valmistajien on kiinnitettävä enemmän huomiota kustannuksiin.

Polttokenno‑auton hankinta voi maksaa enemmän kuin vastaavan kokoiset perinteiset autot. Kuitenkin kehittyneissä talouksissa on saatavilla useita kannustimia, kuten Kalifornian Clean Vehicle Rebate Projectin tarjoama 4 500 $ alennus (7 500 $ tulo‑kelpoisille ostajille) ja muita. Vaikka nämä kannustimet lisäisivät omaksumista ja näkyvyyttä lyhyellä aikavälillä, pitkän aikavälin menestys riippuu ainoastaan tarjotuista turvallisuus‑ ja suorituskykystandardeista.

Klikkaa tästä oppiaksesi, mikä teki vedystä jälleen houkuttelevan energialähteen.