Byron McCormick, a pioneer of the hydrogen fuel cell at General Motors, invented the term ‘energy security’ in 1999, noting, “There may even be war and peace difficulties.” How accurate he was, and if there was ever a moment to bring attention to the essential need for renewable energy, now is it.
Aside from fuel cells, a modest but steady development is creating hydrogen combustion engines. With its work on hydrogen-fueled combustion engines, JCB is demonstrating this, while Toyota is researching the same principle with automobile engines.
Of course, port-injection petrol engines had been tried before, but the poor volumetric efficiency of burning hydrogen gas in an engine built for atomized liquid fuel resulted in significantly lower specific output (bhp per liter) and higher pollutants. Direct injection and high compression ratios in specially constructed combustion chambers have changed that, which is why JCB and Toyota have been successful with their latest engine and electrical hardware.
However, many leading engineers and scientists in the field of sustainable energy believe that batteries are a superior alternative for storing electricity than hydrogen. They argue that the process of producing electricity sustainably, then converting it to hydrogen, compressing it, and finally delivering it to a vehicle is considerably less efficient than simply producing power and storing it in a battery.
However, instead of using a mechanical pump, it may be able to optimize the energy equation in one leg of that process by compressing the hydrogen as it is created using high-differential electrolysis. Conventional electrolyzers create hydrogen at low pressures, but Honda’s ‘high output pressure’ version (first tested in 2010) has now been utilized to fill the compressed hydrogen tanks of fuel cell automobiles at 300 bar. It can now fill them at 700 bar, the pressure required to obtain a range comparable to that of conventional automobiles with a hydrogen fuel cell.
There are operational benefits in addition to improved energy efficiency. Mechanical compressors account for 13% of the time spent on maintenance in present retail hydrogen filling stations, which is an expense that might be eliminated.
Interest in hydrogen as a home gas is growing, and testing in the United Kingdom is underway to see if diluting natural gas with 20% hydrogen is feasible. The Whitelee project in Glasgow, which will create and store enough green hydrogen to power 225 buses from Glasgow to Edinburgh on a daily basis, was revealed at Cop 26. The hydrogen will be produced by the Scottish Power Whitelee Windfarm and transformed to hydrogen by the UK’s biggest electrolyzer to date, which will be built by ITM Power.
Given that one of hydrogen’s primary advantages is its ability to store energy generated off-peak by converting it to hydrogen, the Whitelee project should demonstrate a sustainable energy solution that has been discussed for two decades but has lacked a meaningful motivation to become a practical reality. Today’s acute need for energy security might be it.
Ford is collaborating with a Purdue University research team to create a cooled quick charger cable that will enable charging times to match the time it takes to fill up with gasoline or diesel. Rather than merely cooling with liquid, the cable coolant ‘changes phase’ from liquid to vapor, removing substantially more heat. However, the project is still in its early phases, and prototype testing will not begin for another two years or more.
