Energy sources of the future need to be low or zero carbon if they are to be used in a world that has greenhouse gas emissions set to zero* to limit global warming.
It is this constraint that has seen the future of thermal coal brought into question because, as with all fossil fuels, the burning of coal for power generation releases lots of greenhouse gases into the atmosphere.
But there was good news last week from Australia’s Chief Scientist, Dr Alan Finkel, who told the Energy Ministers of the Council of Australian Governments (COAG) last week that Victorian brown coal could be a cost-competitive feedstock for the production of hydrogen gas.
Hydrogen is an energy source that is zero emission in use. It can be used in various ways – notably in fuel cell technology. In fuel cells in cars and trucks it does what coal could never do – be a viable transport sector fuel.
For the production of hydrogen from coal to itself be low or zero emission, the processing would require carbon capture and storage – with a carbon dioxide pipeline from the Latrobe Valley to the depleted oil and gas field of the Bass Strait, where it could be stored indefinitely.
A critical problem for hydrogen use has been that it is a low-energy gas and therefore costly to transport. But in a major breakthrough by the CSIRO also announced last week, that problem has been solved by the use of membrane technology to efficiently transform hydrogen into ammonia and vice versa. Ammonia is far more cost-effective to transport to markets around the world.
This means that Latrobe Valley brown coal – only ever used for domestic power generation because of its low energy content – could be the basis of a new export industry sending ammonia around the world that can be converted to hydrogen for emission-free energy in transport and many other sectors. This could provide an alternative large industry for the Latrobe Valley as brown coal power stations close.
The CSIRO announcement also claimed that the ammonia could be produced from nitrogen in the atmosphere using renewable energy. But if the Chief Scientist is correct, using brown coal with CCS will be more economic as well as low to zero emission.
* the term used is actually “net zero”, which means that low levels of emission can be offset with measures that absorb carbon to create an overall or “net” zero outcome.