A major role for green gas in sustainability

The government’s climate plans predict 2 billion m3 of green gas by 2030. In 2018, this was only 100 million m3. Network company Alliander is one of the companies that ensures that the green gas is fed into the natural gas network. Innovation manager Pieter Mans sees a role for green gas parti­cularly in cities like Amsterdam, where alternatives to natural gas are very expensive.

Green gas is sustainable because it is pro­duced from the fermentation of organic waste, such as prunings, food waste and manure, but also from wastewater from paper mills (see box). The gas released during fermentation is not yet suitable to replace natural gas. To do this, it first needs to be ‘reprocessed’. In this process, the compo­sition is adjusted so that it is the same as natural gas. This is necessary to prevent the boiler from playing up.

Huge potential

Green gas has not been around for that long. Alliander introduced green gas into the natural gas network for the first time in 2012. Since then, the market has grown steadily. In February 2019, Alliander connected its fifteenth supplier to the grid. In 2018, some 100 million m3 of green gas found its way to the consumer. The share of the total gas consump­tion of approximately 40 billion m3 is still very modest. But accor­ding to Mans, the potential of green gas is enormous.

One of the suppliers is Groen Gas Gelderland in Bemmel. This company produces 9.5 million m3 of green gas annually. It pro­cesses 72,000 tonnes of biomass, mainly manure from farms, but also roadside grass and residual products from agriculture and the food industry. The gas is supplied to the normal gas network.

Supply and demand

Such an additional supplier does impose requirements on the gas network, says Mans. “The pipelines were once laid with winter peak demand as the starting point. They can handle it. But you also have to deal with supply and demand. The Groen Gas Gelderland factory delivers continuously, day and night, all year round. In the summer, that was more than gas consumed in the area of the network, the immediate vicinity of the factory.

To resolve the bottleneck, Alliander connected the gas network to that of the city of Arnhem, just north of the factory. This solved the problem, because the gas consumption of such a large city is also much greater on summer days than the production of the plant.

Groen Gas Gelderland receives a subsidy from the Ministry of Economic Affairs. This scheme is still essential for green gas, because production is more expensive than Slochteren’s gas, which is almost free of charge. Green gas also produces a little more, because consumers are prepared to pay more for a green alternative. But that is not enough to cover the costs.

Strong growth providers

Green gas can play an important role in the energy transition, says Mans. The Climate Agreement assumes that production will grow to 2 billion m3 by 2030. The number of suppliers will have to grow substantially, by about three to four hundred. “How the govern­ment will achieve this is a policy question. I can imagine that subsidies will be used and that the procedures for permits will be accelerated.”

Alliander’s challenge is to ensure that these new suppliers have flexible access to the gas network. The joint network managers will have to invest around € 300 million in the coming years to make this possible. The government has announced that a ‘Roadmap’ will be drawn up this year to stimulate innovation, production and use of green gas.

Wrong kind of water

Industriewaer Eerbeek purifies the water of Paper mill ‘Coldenhove’ BV, SCA Packaging De Hoop and Mayr-Melnhof Eerbeek BV. This involves anaerobic treat-ment that produces biogas. This generates approximately 10 GWh of electricity annually. IW Eerbeek uses a third of this for its own operation processes; the rest of the electricity is fed back into the grid by the water treatment company.

The water treatment plant treats the water that is contaminated with solids (fibres, chalk and clay) and dissolved substances (organic material and salts). This involves 4 million m3 of wastewater and 9,000 tonnes of sludge per year. This is comparable to the wastewater from a city like Utrecht. The purification process produces 4 million m3 biogas annually, which produces around 10 GWh of electricity per year.

Gasless more often

Two billion m3 may not sound very much out a total consumption of 40 billion m3. But the use of natural gas will decline in the coming years. The importance of green gas will then increase. New homes are already gas-free and existing homes are also increasingly using technologies that make the gas redundant or at least significantly reduce gas consumption.

“Many buildings in the city centre of Amsterdam, in particular, are difficult or impossible to electrify, or only at very high costs,” says Mans. “Moreover, many buildings have monument status, you can’t just start altering them. And there is no room for the construction of a heat grid. Then green gas is the perfect solution to make it more sustainable.”