Coal seam gas (CSG)

Coal seam gas is one of the highest quality and cleanest forms of thermal energy in the world, typically comprising less than 2% CO₂ and about 95% methane. Because of this, it produces less greenhouse gas emissions than conventional natural gas, which can contain up to 50% CO₂ when brought to the surface. CSG’s significant potential is being recognised around the world – it already provides 15% of the USA’s gas supply and close to 90% in Queensland, Australia.

Why CSG?

It is another form of indigenous natural gas that can offset the declining production of New Zealand’s Maui gas field.
The small wells do not disrupt existing land use, making it easy for farmers to supplement their business income with CSG royalties.
It creates fewer greenhouse emissions than any other thermal energy.
It supports distributed generation by contributing electricity to the national grid from multiple points around the country, potentially avoiding expensive transmission upgrades.
Electricity from CSG would provide base load generation to support further renewable electricity generation projects.

How does it work?

When coal forms in the ground, the associated chemical and biological processes produce methane gasses. This methane adsorbs onto the surface of the coal and stays in place because of the high underground pressure within the coal seam. By pumping water out of the coal seam, we can lower that pressure so the gas is released and then channel it to the surface for electricity generation or heating.

What are we doing?

Solid Energy is exploring for CSG in the Waikato, Taranaki and the West Coast of the South Island. Exploration is most advanced in the Waikato, where test wells have yielded high quality gas containing 98% methane and just 1% CO₂. Exploration is continuing across all three sites.

Click here to learn about the difference between coal seam gas and underground coal gasification.

Some of our New Energy research projects include:

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