As transit agencies move away from fossil fuels, they are figuring out which environmentally friendly option is right for them.
Public transit agencies are often among the first customers for vehicles that run on new types of fuel, whether it was cleaner-burning diesel in the 1990s or natural gas more recently.
Today, eco-conscious agencies looking to switch to electric fleets face a big choice: power them with rechargeable batteries or with hydrogen fuel cells?
There isn’t an obvious answer. Both are more environmentally friendly than fossil-fuel buses, and both can be cost-effective options.
Hydrogen vehicles are more expensive to buy and run than battery electric vehicles but have a far greater range.Vivarail trains battery class 230 60 mile range,hydrogen class 230 650 miles.UK train leasing company Porterbrook investigated what it calls alternative fuels battery,supercapacitor and flywheels and judged none of the technologies could provide the 500 mile range it needs so it is converting 1980s ex Thameslink class 319 diesel trains to hydrogen.
On the subject of buses,£200,000 diesel,£250,000 diesel hybrid,£350,000 battery and £500,0000 hydrogen London double decker buses so the new battery double decker buses are cheaper than hydrogen but the new hydrogen buses can run on longer routes.Another problem is night buses which are in service 23 hours a day,1 hour isn`t enough time to charge batteries for 23 hours but the new hydrogen buses refill in 5 mins which can power the buses all day.
Unlike hydrogen cars which compete with electric cars I think that the more costly hydrogen buses,trains,trams,ships and ferries as well as in future planes will be used only for long distance routes with less expensive battery versions for short routes.
Mayor Sadiq Khan and TfL want to replace the new Routemaster buses which were only made in 2011-17 with new electric buses,one Aberdeen Council`s refuse lorry was converted to hydrogen (watch Fully Charged Show youtube episode Alternative Fuel Trucks and Vans)and a Greenwich Borough,London refuse lorry was converted to battery power saving £300,000 over 14 years so I think it will be much cheaper and quicker to convert new Routemaster buses and other newish diesel and hybrid buses to hydrogen and/or battery power and greener,reduce,reuse and recycle,the new Routemaster is a hybrid so it will be even less costly to convert as the bus already has a battery pack for regen and an electric motor.
Nearly all hydrogen today is made by steam methane reformation. Because of energy losses in conversion, you need substantially more methane than if you burned it in the vehicle directly. So as things stand, using hydrogen to power a vehicle has a greater carbon output than running it on fossil fuel.
If you make your hydrogen by electrolysis, because of energy losses in conversion, it takes about 3 times as much energy to power your vehicle than by battery. The CCC has said that it is impractical to make hydrogen on a large scale by electrolysis. Even if you did, you would only get a carbon saving relative to burning fossil fuel directly once the fossil fuel intensity of the grid is sufficiently low. And the grid expansion requirement would be much larger if very many vehicles ran on electrolysed hydrogen rather than on batteries.
The CCC has said that hydrogen has a role in future because we will make it by steam methane reformation and then use carbon capture and storage (CCS) to make that a low carbon fuel. We do not have a practical demonstration of CCS at a sensible cost yet, having cancelled the demonstration projects due to overspends. Nevertheless CCC says CCS must be made operational because it is the only viable strategy for a fully decarbonised grid. Methane generators are needed when light and wind are low. If instead, we used battery storage, pumped storage, or equivalent, to cover such temporary energy shortfalls, that would be vastly expensive. The country would need energy storage on the scale of hundreds of Dinorwigs, one of the largest pumped storage schemes in the world. Dinorwig has a storage capacity of 9GWh. The largest present day battery schemes store on a scale of tens of MWh.
Some people have suggested that this runaround makes no sense. Just run your vehicle on fossil fuel and carry out direct air capture of the relevant quantity of carbon dioxide, paid for by a levy on the fuel.
It doesn’t help that there have been two hydrogen explosions so far this month, one in California where a tanker was being loaded, and one at a car refuelling station in Norway. Norway has form. In 1985 an explosion at a steam methane reformation plant demolished a brick-built building 100m long, and broke all windows in a radius of 700m. The quantity of hydrogen which exploded was assessed to be about 3 to 7kg, and it exploded less than 30 seconds after the leak commenced. 2 people died.
For trains, sensible countries will cover the greater part of the requirement by extension of the wires. Most countries can electrify railways at a fraction of the cost we require in Britain. Britain could learn to copy them, which would involve a major culture change. Whether we succeed in doing that or not, it can also be made cheaper by having gaps in awkward locations, eg where bridges would have to be raised at enormous cost, and modest battery power to get over the gaps. There are technical difficulties in discontinuous electrification, but we have to get good at it, the money to be saved is large. The batteries can be recharged while travelling under the wires.