How OGE is mastering the market area conversion.

From L to H in 18 years.


There are places that almost nobody outside the natural gas industry has heard of, but within it almost everybody has. Slochteren is one of these –a rural community in Groningen in the Netherlands. Here there are more cows (180,000) than people (14,780), and until 1959 there was no industry. That was the year that Slochteren appeared on the global energy map, because in 1959 the EU’s biggest natural gas reservoir was discovered here. With original reserves of 2,800 billion cubic metres, it is the ninth biggest in the world. Natural gas was to be extracted in Slochteren right up until 2050 — with large proportions of it exported to Germany. Or so we thought.

Since the early 1990s there have repeatedly been earth tremors in the Groningen region, including stronger shocks measuring more than 3.0 on the Richter scale. For this reason, the Dutch government decided to gradually scale down natural gas production: from an original 50 billion cubic metres a year to 30 in 2015 and then to fewer than 20 in 2019.

The Netherlands is phasing out natural gas production — ahead of time.

The Dutch parliament resolved to end exploration of natural gas completely in 2018, whereby the plan was for the last natural gas to be extracted from Dutch earth in 2029. In May 2019, however, this plan was torn up and on 10 September the Dutch Minister of Economic Affairs Eric Wiebes announced that in a normal year (a year with average temperatures) production could be suspended as early as mid-2022. The field could then be closed down completely as early as 2026.

A story resonating further than the Netherlands.

Germany, as one of the most important recipients of Dutch natural gas, is also affected by this decision. Here, millions of households as well as industrial and commercial users rely on Dutch gas for heating. The gas used is L-gas, which differs from high-calorific H-gas coming from Norway, Russia and the UK in its low calorific value.

OGE is observing the situation closely, but without concern.

Current planning for the gradual market area conversion from L-gas to H-gas is unaffected, since the Dutch have said they will stick to their contractual obligations. In order to ensure this, special measures are being taken in the Netherlands, most notably the increased use of conversion plants. This means that the Dutch are using admixing facilities to turn H-gas into L-gas, which is then shipped to the German recipients.


L-gas on the way out.

Aside from the events in the Netherlands, L-gas is becoming obsolete in any case. In future, the whole of Europe will be supplied with H-gas, so the patchwork maps of L- and H-gas regions supplied by different pipeline networks, distribution centres and delivery points and with differently calibrated end user appliances will be a thing of the past.

Germany is itself divided in terms of natural gas provision: There is a large H-gas area stretching primarily over the south and the east, and an L-gas area that comprises Lower Saxony, North Rhine-Westphalia, Hesse, Rhineland Palatinate, Bremen and Saxony-Anhalt.

Inspecting, adapting and re-checking appliances: 5 million times.

Around 5 million gas appliances and plants will have to be converted to H-gas by the year 2030. Installation engineers will have to make more than 10 million visits to the end appliances: In the first step the appliances are recorded or surveyed and then modified in a second step, generally involving a change of nozzle. It’s a huge project and an enormous organisational challenge. And at the start of the process chain is one of Europe’s biggest gas network operators.

The first preliminary planning began in 2012. All the transmission system operators in Germany grouped together in committees, with the essential coordination taking place by means of the Gas Network Development Plan. After all, for the conversion to go smoothly the entire supply chain has to run like clockwork. That means from the gas field in Groningen to the installation engineer who ultimately modifies the gas boilers.

Four to five years in advance.

With this broad horizon of time, OGE reached an agreement with its customers — the distribution system operators and industrial gas users — concerning the conditions of the conversion. The long lead times are necessary because the customers have their own long-term planning processes, and because OGE has to expand and adapt its own pipeline network. The H-gas has to reach all areas currently supplied with L-gas. Hence, bit by bit OGE is developing new transmission routes and in the process is investing around € 1.5 billion in its pipeline network for the L-/H-gas conversion.

Step by step, the distribution grids are being converted. This is typically done in parcels of between 20 and 30,000 appliances with few delivery points to the distribution system operators. These parcels are dealt with according to a meticulous plan, with L-gas being gradually displaced by H-gas.

What does a project need to succeed? Communication!

Everything is planned and calculated jointly with the distribution system operators. How big are the conversion areas? How should the network be divided up? How many specialists are required when and where? OGE sees itself as a pacesetter, initiating processes, organising industry gatherings and communication platforms, advising and coordinating. At the same time, those responsible are ensuring that the pipeline structures in their own transportation network are also being adapted.

OGE’s communication and coordination is working: There has been much positive feedback from distribution system operators, who are happy with the support they are getting.

Delays? Not likely.

The best-laid plans go to waste, they say, but this does not apply when it comes to the market area conversion. Delays or other deviations from the basic plan are not foreseen, and year by year up to 550,000 appliances in the distribution grids are being converted. The resources for the necessary work have been planned and contractually agreed for years. The same goes for the network expansion work, which of course has to be completed on time.

And, in fact, everything has gone smoothly so far.

After H comes G.

H-gas is more efficient than L-gas. It is, however, still a fossil fuel, so in the not too distant future, H-gas will be phased out in favour of so-called green gas, which is gas obtained through renewable energy such as wind power and hydrogen. With its 12,000-km pipeline network, OGE is ready for the change.