25 Nov 2017

Powering Japan: mining undersea 'fire ice'

From This Way Up, 12:50 pm on 25 November 2017

How can one of the world's leading industrial nations become energy self-sufficient, and avoid paying so much for the fuel imports that cost the economy tens of billions of dollars every year?

Structure of a gas hydrate (methane clathrate) block embedded in the sediment of hydrate ridge, off Oregon, USA.

Structure of a gas hydrate (methane clathrate) block embedded in the sediment of hydrate ridge, off Oregon, USA. Photo: (By Wusel007 - Own work, CC BY-SA 3.0)

With meagre energy reserves of its own and only a fledgeling interest in renewable power, Japan must import the bulk of its oil, coal and gas from overseas.

But now attention - and government investment - is turning to an untapped natural resource buried deep beneath the seabed.

So-called flammable ice (aka fire ice or methane hydrate) is a mix of water and methane locked away under high pressures and low temperatures in the Arctic permafrost and deep down under the ocean floor.

According to NIWA, there's a huge stash off the East Coast of New Zealand, too.

A 3D image of one section of East Coast seafloor mapped in 3D, complete with methane deposits and flares.

A 3D image of one section of East Coast seafloor mapped in 3D, complete with methane deposits and flares. Photo: [NIWA]

These methane hydrate reserves have been called the world's largest source of untapped fossil energy, storing more energy than all remaining fossil fuel reserves combined.

But recovering them in a cost-effective way that won't harm the planet is no easy task.

For CNN, Sarah Lazarus has been looking at the prospects and possibilities of flammable ice as an energy source.

"These ice crystals hold a remarkable quantity of natural methane gas. It is estimated that one cubic meter of frozen gas hydrate contains 164 cubic meters of methane. Hold a match to the ice and the gas ignites so that instead of melting, it burns" Sarah Lazarus

"If natural gas could be extracted economically from gas hydrates, it would reshape the energy world. The implications are astounding. The price of natural gas, throughout the world, would be pegged to the price of extracting the hydrates." Professor Christopher Knittel of MIT's Sloan School of Management quoted by Sarah Lazarus

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