The background: In many ways this is about far more than Toyota's new Mirai hydrogen fuel cell saloon. Of course, the car is worthy of serious note in itself - after all it only emits water. But the true import of its existence is how it adds fresh impetus and direction for future motoring.

The Mirai is Toyota's shop window, another starting point on how we can use hydrogen to fuel cars, trucks and vans.

The concept and technology have been evolving for decades - it is many years since I first drove a hydrogen-powered Merc. But the technology is being refined continuously by Toyota and others.

Yet before we drive one in Ireland, people - politicians and business chiefs especially - will have to create an environment and infrastructure to accommodate it. Therein lies the rub.

Yes, there is a legitimate question to be asked: Is it worth it? Spending millions on hydrogen stations (more than €1m each) doesn't seem to make sense, initially, at least. The same could be said, I suppose, about our electric-vehicle infrastructure for now but not for the future. So we have to look beyond 2020 to 2030, 2050 even.

To drive a hydrogen Fuel Cell car - as I did the Mirai around Hamburg recently - is to not just glimpse the potential of that future focus. It is to see how we could - stress could - radically change how we think about what will power our vehicles over the next two or three decades.

It probably struck me most forcibly as I topped up the tank at a hydrogen station. Could I see myself doing so in Tullamore in 2020? I don't know. One half of me asked: why not?' The other half asked: 'Who will make it happen?'

Toyota say it hopes to have hydrogen vehicles here - in small numbers and on lease - within five years. As of now, one would cost upwards of €85,000, but leasing would be around €1,000 a month.

Ultimately we are not going to be able to depend on any one mode of propulsion. Diesel, petrol, electric, hybrids and plug-in hybrids all have big roles to play. But with the emission-regulation noose tightening by the year we will have to find complementary alternatives too.

Hydrogen Fuel Cell Vehicles (FCVs) are likely to be only one of several recourses. Yet if we don't start plotting and planning now for the likes of the Mirai and the use of hydrogen in trucks, vans and buses, we could find ourselves with even heftier emissions and pollution difficulties in the years to come. Merely cutting dependency on fossil fuels through lower consumption will not be enough.

In an ideal world, perhaps, electric vehicles hold a key solution but until battery technology erases range anxiety it is hard to see mega growth for low-cost examples. And there is the question of the pollution caused by generating the electricity in the first place.

The thing about hydrogen is it can be a by-product of many things - and is especially suitable for storing excess electricity.

We have to be careful about seeing it as a panacea. Toyota executives in Hamburg made it clear this is for the long haul and is part of an overall solution. But only by starting and refining will there be progress. The Mirai is one of several new-world hydrogen fuel cell vehicles that run on electricity generated by the chemical reaction between hydrogen and oxygen (the only residue is water - not NOx or CO2).

Unlike electric cars, however, Fuel Cells have much the same range as a petrol or diesel and you can re-fuel quickly (3-5 mins); no long waits for charging up. If I can do it, and I did, then anyone can.

The only drawback is you need an infrastructure of (for now costly) hydrogen stations. They are already building these in places such as Denmark, Germany and the UK. In Denmark they have sold/leased eight cars already. There is no purchase tax on them - which compares with the 180pc they shovel onto 'ordinary' cars. That shows how seriously some governments are taking it.

The thing about hydrogen is you can make it from nearly anything - from sewage sludge to wind power. When it is compressed it is fairly easy to store - and is claimed to be as safe as any other fuel. They have gone to great rounds to make sure of that in the Mirai.

As of now, hydrogen is mostly made from natural gas or biomass - which involves using energy to make it. So there is an environmental impact. You get nothing for nothing. But depending on how it is produced, you can cut overall CO2 by 40pc-70pc compared with a conventionally powered vehicle. And if you use renewable energy, the footprint recedes further.

ON THE ROAD Ours was a silent drive, except for a whirr when going fast. But there was no road/tyre noise which is testament to body parts being sealed, use of acoustic glass in the windshield, windows, and body frames stuffed with sound-insulating materials also used around the bonnet.

Top speed in the Mirai is 178kmh. You get full-on torque from the start - as with all electrically-powered vehicles. You also get 0-100kmh in 9.6 seconds. It felt sharp. The car's low centre of gravity is helped by the motor, two hydrogen tanks and battery all being slotted underneath.

The seats were seriously comfortable (front electrically adjustable with lumbar support).

Driving was as simple as pushing a lever into D. Two triangular window slots in the rear corners were a big help for visibility.

They were right to have just two seats in the back and there was plenty of room all round in a nicely spacious cabin.

There is a long list of safety elements - eight airbags, Pre-Collision System, Adaptive Cruise Control, parking assist sensor system and rear-view monitor. Especially handy in parking lots are the automatically retractable outer mirrors. There is a smartphone charging area in the centre console box, though it didn't work for my Samsung.

The hydrogen is stored in two high pressure (700 bar) tanks. In the event of a leak, sensors that detect minute amounts of hydrogen immediately shut down the safety valves and the vehicle itself. We spoke at length with Yozisahabe Takana, the chief engineer of the Mirai. He emphasised safety in great detail. Heck, as part of the safety brief in construction they fired a bullet at a tank to no avail.

And the cabin is separated from the hydrogen compartment to prevent penetration of any leaks. There are extensive precautions to make sure refuelling is safe too.

THE ROAD AHEAD They are making 700 Mirais this year, 2,000 next, 3,000 in 2017 and 30,000 globally by 2020.

Chief engineer Tanaka warned that oil prices won't always be so low. In the long run prices will rise, he forecast. Electricity prices are rising too. "The journey starts from here," he told us.

Hamburg was chosen because it has one of the most advanced hydrogen cities in Europe. They want to cut emissions by 40pc by 2020. The already have six FCV buses. Significantly there is big political support.

Without it in Hamburg or Ireland, nothing can happen.

It is now over to the car companies, industry and politicians to map the road ahead.

Indo Motoring