Why Hydrogen Engines Face a Narrowing Window of Adoption in the Commercial World

(AZO CleanTech) In 2025, Europe's second-largest truck OEM, MAN Truck & Bus, will deliver 200 hydrogen trucks powered by its in-house H45 hydrogen combustion engine. These trucks will emit less than 1 g of CO2/tonne-km (drastically lower than a comparable diesel), with ranges up to 600 km and 15-minute refueling. They also require no heavy and expensive lithium-ion batteries, yet according to MAN will meet the EU's criteria for a zero-emissions vehicle. How is this achieved, and with such strong credentials, why are more in the industry not moving towards hydrogen internal combustion (H2ICE) as a zero-emissions solution?

IDTechEx report examines the energetic pathways involved in BEV, FECV, and H2ICE powertrains. H2ICE has the lowest overall energy conversion rate, with extensive losses in both hydrogen production, distribution, and combustion. Image Credit: IDTechEx

As covered by IDTechEx in its in-depth review of the subject, "Hydrogen Internal Combustion Engines 2025-2045: Applications, Technologies, Market Status and Forecasts", H2ICE is being explored as a solution for hard-to-abate transport sectors by a variety of OEMs. IDTechEx research indicates that while hydrogen chemical properties result in slightly different combustion characteristics to conventional gasoline/diesel engines, a suitable performance can be achieved with the right engine operation (lean burn spark-ignition with a λ > 2.2)

As reported by IDTechEx, as of July 2024, there were 1063 hydrogen refueling stations (HRSs) globally. This compares with some 4 million EV chargers available globally in 2023, an order of magnitude larger. HRSs are also highly regionally focused, particularly in China, Korea, Japan, and California. Although the general trend has been an increase in HRSs available, this is not the case in some regions.

Germany has the largest rollout of hydrogen refueling infrastructure in Europe. The period up to 2022 saw strong growth in the number of H2 stations however, the past two years have seen stagnation at around 80 stations. Some HRS have even closed, such as the several stations Everfuel announced closing in September 2023. It cited "immature hydrogen mobility market and technology".

California has also seen closures. In early 2024, Shell announced the permanent closure of its 5 HRS in the state. This came after earlier plans for 48 new Shell-built HRS were canceled, before 3 of the 5 stations were temporarily closed in September 2023. Finally, in February 2024, Shell announced that these closures would become permanent and apply to all of their stations, marking a major blow to the rollout of hydrogen infrastructure across the state. Shell cited "political and economic uncertainty in the initial stages of market deployment". READ MORE

Excerpt from EnerDynamics: Losses in generation, transmission, and distribution
First, let’s consider the primary energy that enters the electric delivery system at the input to the generator and examine how much of the primary energy is delivered to the customer. According to the Energy Information Administration (EIA), the answer is 34%. In other words, 66% of the primary energy used to create electricity is wasted by the time the electricity arrives at the customer meter.

Where does all this waste go? It is primary energy that is converted to heat and then lost as waste heat. Here is where losses occur:

Generation
It is estimated that of the 66% lost, 59% of it is lost in the generation process. This includes:

Transmission and distribution grid
Another 5 to 7% of the original primary energy is lost during the delivery of electricity through the T&D system. The energy becomes waste heat released in the air due to line losses and conversion losses in transformers and other line equipment. READ MORE

Excerpt from Yale Climate Connections: Traditional electricity generation has a thermodynamics problem: Burning fuel to generate electricity creates waste heat that siphons off most of the energy. By the time electricity reaches your outlet, around two-thirds of the original energy has been lost in the process.

This is true only for “thermal generation” of electricity, which includes coal, natural gas, and nuclear power. Renewables like wind, solar, and hydroelectricity don’t need to convert heat into motion, so they don’t lose energy.

Transmission and distribution cause a small loss of electricity, around 5% on average in the U.S., according to the EIA. The longer the distance traveled, the more the loss of electricity from transmission lines, and this energy loss is the same no matter what type of energy feeds into the grid.

Energy storage is an increasingly common part of the electricity supply, and storage is an essential element of decarbonizing the electricity grid. How much energy do batteries lose? The round-trip efficiency of large-scale, lithium-ion batteries used by utilities was around 82% in 2019, meaning 18% of the original energy was lost in the process of storing and releasing it. Batteries are getting more efficient over time, and the Department of Energy’s grid storage research uses a battery efficiency of 86% in its estimates. READ MORE