Ancient engineering, modern LNG and the possibility of turning Europe’s railways into a rolling energy network
The Ancient Art of Moving Heavy Things
Who invented railways? Easy, you say. The Brits, when the Industrial Revolution began to gather serious momentum. And yes, they revolutionised land transport.
For the first time, moving large and exceptionally heavy objects became part of ordinary life, without requiring extraordinary means.
Right?
Wrong.
The idea that a track could make the transport of very heavy goods practical is more than 2,500 years old. More than 2,000 years before the first iron horse ever wheezed its way into history.
Introducing: the Diolkos.
Can we trust historical archives and archaeology? If we can, this six-kilometre trackway crossing the Isthmus of Corinth was the first true railway.
Yes, we are in ancient Greece. And a glance at the map tells you that this particular corner of the world comes with a rather wild and dangerous coastline.
To the south, the almost-island of the Peloponnese thrusts itself into the Mediterranean. A wild sea, once teeming with pirates, made travelling from the Adriatic Sea to the Aegean islands a long and distinctly perilous undertaking.
The Peloponnese is connected to mainland Greece by the Isthmus of Corinth. Whoever could cross it possessed an enormous advantage over anyone who could not — in war, and in commerce.
The purpose of the Diolkos was to drag entire ships across the Isthmus. It was a paved way with grooves cut into the stone, providing a smooth surface on which large wheels could roll. Carts drawn by beasts of burden helped haul the ships across.
Why, you may reasonably ask, is this interesting information for an energy blog?
Because the ancient Greeks already understood something rather fundamental: if you want to transport something large and heavy, you need smooth rolling. As smooth as possible. Every bump in the track produces friction. And friction is invariably bad when you are trying to move large, heavy things.
Or when you are moving a lot of things, even if each individual thing is quite small.
The Diolkos did not provide for unloading the ships, transporting their cargo across the Isthmus, and reloading everything onto another ship. They dragged the entire ship across because, quite sensibly, they had concluded that doing so was cheaper.
A remarkably modern piece of thinking, really.
From Iron Horses to LNG
Let us fast-forward more than two and a half millennia.
Today, railways are something of an oddity. They had their heyday during the nineteenth century, before the triumph of the automobile.
Before petroleum, coal was the fuel of choice. Automobiles were not large enough to carry enough fuel. The great steam engines powered by coal fitted rather comfortably on great things.
They did not fit particularly well into small cars.
And here we get to LNG.
LNG remains something of an oddity in the transport world. Even more so in the railway business. But it is hardly unheard of. LNG has been used as a railway fuel for decades, albeit mainly in the form of exotic laboratory exercises. It never quite made it into the mainstream.
That is now changing.
Some countries are beginning to walk new paths by combining LNG with rail.
Russia is trying to use more gas as a transport fuel and is building new LNG-fuelled locomotives. As a rather useful side benefit, they do not need to heat the fuel in the far north as they have to with diesel. Even the coldest day in Siberia would feel positively balmy to LNG.
Countries as diverse as India and Spain are experimenting with both LNG as a fuel and LNG transport by rail.
And, as so often happens, the United States is once again the tip of the spear, in a sense.
Copious shale gas and massive overproduction of methane are driving a powerful push towards greater use of LNG. This LNG is best produced at central locations and distributed to many parts of the country.
And let us not forget the route south, towards Mexico, which is a substantial market in its own right.
The volumes possible are astonishing.
A single Chart LNG carriage holds about 100 m³ of LNG. A super-long block train with 100 carriages therefore holds 10,000 m³ of LNG.
That means that one such block train per day would deliver more than 1.5 million tonnes of LNG, or roughly 2 bcm of gas, per year.
We are entering pipeline territory.
Large cities need that kind of gas.
The Rolling Pipeline
Today, building pipelines is difficult because of activists and populist politicians. LNG trains could provide rapid relief when matters eventually come to a head.
And they will, if activists succeed in blocking conventional pipeline development for long enough.
Yes, New Yorkers and Californians might be among the first recipients of such LNG trains. One day, they may decide that the efficiency and reasonable economics they have surrendered should perhaps be invited back into their lives.
But the most exciting territory might be Europe.
I know. That sounds counterintuitive.
Europe is hardly innovative in any meaningful sense. Except, perhaps, when it comes to implementing pie-in-the-sky energy solutions with extraordinary determination.
But it is precisely for this reason that LNG trains might become a feature here.
It is at least as difficult to build a pipeline in Europe as it is in the United States. The compliance requirements and administrative long tail can kill projects long before they ever get properly underway.
Europe, however, also has a remarkably dense network of railway tracks.
Many of those tracks date back to a time when railways were a much more important feature of everyday life. Those lines often reach into some of the remotest corners of the continent.
In some regions, such as the Balkans, gas pipelines are scarce. Gasifying the region is difficult because new infrastructure is difficult to build and requires a great deal of capital upfront.
Investments that, rather conveniently, cannot always be backed by public money.
But those same regions have a fairly dense rail network.
Sending LNG block trains from coastal terminals would provide a way of connecting many island communities and cities to the gas world.
In gas terms, if you are not connected to the grid, you are an island community.
The Problem of the Peak
But even cities that are already well integrated into the continental gas grid might become interested in LNG trains.
Cities that use large quantities of gas for domestic customers have to deal with violent swings in consumption.
The seasonal swing is the more famous one.
In Europe, most cities use considerably more gas in winter than in summer.
Heating is the culprit.
Depleted gas fields are used as underground storage. During the low season, gas from long-term deliveries is injected into storage. Those volumes can then be returned to the grid during winter, on top of the volumes being delivered at the time.
It is a slow process, but the swing is also very long. The two therefore fit together rather nicely.
What is much harder to deal with are the hourly swings.
Take mornings, for example. They usually produce very large peaks in gas consumption. People wake up, make breakfast and take a shower at roughly the same time.
Human civilisation has built an extraordinarily complicated energy system around this daily ritual.
Utilities prepare for those peaks with various countermeasures. In some cases, the peak is so strong that a fast, short-term buffer is required.
This is often a very high-pressure tube that is filled with gas overnight. That gas is then released into the grid when it is needed.
This is very costly.
Another measure is to liquefy gas into a holding tank and regasify it when required.
Again, not cheap.
But the most expensive part of that exercise is the liquefaction itself.
Let that sink in for a moment.
Some countries receive LNG at coastal terminals. They regasify that LNG and put it into the gas grid, only to liquefy it again later when they need it for a short-term buffer.
How wasteful.
Would it not be easier and cheaper simply to keep the LNG as a liquid and bring it to wherever it is needed?
Of course it would.
If only transport were not so expensive.
LNG on Rails
Most onshore transport of LNG in Europe takes place using truck trailers.
One such truck can transport roughly 45 m³ of LNG at a time. That is perfectly adequate for fuelling vehicles, but a city’s requirements are rather larger.
And truck transport is expensive.
Rail would change the equation.
It would be a true rolling pipeline.
How would it work?
Each block train is a lump of gas. Each carriage within the block is a sub-lump of gas.
A user with regasification capacity already in place would model its demand peaks over a certain period. It might discover that it needs a particular amount of LNG to shave those peaks every weekday for a certain length of time.
A recurring pattern of sorts.
To reduce its LNG storage requirements, it could arrange for carriage deliveries to arrive and be dropped off at defined intervals.
The customer would maintain a certain safety volume of LNG in a fixed tank because there must always be enough capacity to play with if something goes wrong.
But the right choreography of carriages could keep that tank relatively small.
And tanks are expensive.
Besides, boil-off in small tanks is higher than in large ones.
If the customer anticipates an extraordinary spike in consumption, it could try to line up additional carriages for faster delivery.
It could pack the line.
Those are games, of course, and I would not recommend that anyone immediately embark upon the sharper versions of these models.
But once one becomes comfortable with the fundamentals, more exotic possibilities begin to present themselves.
The Gas Internet
Imagine this happening on a network basis.
Every single carriage has instant communication capability. A SIM card could tie it into the mobile phone network, allowing for real-time monitoring, “just in time” delivery and scenario simulation.
All consumption points, their consumption patterns and all rolling stock could be rearranged by intelligent algorithms, ad infinitum.
The railway network would cease to be merely a collection of tracks carrying trains from A to B.
It would become a distributed energy system.
A physical network carrying liquid gas, coordinated by a digital network capable of continuously matching supply, storage, transport and demand.
The ancient Greeks understood that moving heavy things requires smooth rolling.
Two and a half thousand years later, perhaps we are finally ready to take the idea to its logical extreme.
The European rail network could become the continent’s clean energy internet.
