The interesting concept of introducing hydrogen into natural gas took a step forward this week as new announcements were made regarding clean energy initiatives.
The ‘hydrogen into natural gas’ was one of two initiatives announced for South Australia. The other is a more substantial investment in molten salt technology already in use in the USA.
Adelaide’s Advertiser newspaper this week described the hydrogen mix concept as a “trial that could pave the way to a zero emissions gas network”.
The concept has been bubbling away on the scientific backburner for some years, with sound science, but without an economic solution.
Hydrogen in natural gas (mostly methane) has always been a good concept. Burning methane releases carbon, but burning hydrogen does not. Substituting hydrogen for methane therefore reduces carbon emissions.
However hydrogen is too expensive to make this viable. Breaking water molecules (H20) to release hydrogen takes a lot of energy – too much to make it commercially viable.
Now a joint venture between Adelaide-based company Australian Gas Networks and NSW’s AquaHydrex will aim to convert it to a real commercial proposition for Australian conditions.
A pilot plant will be built at Adelaide’s Kidman Park, thanks to a $5 million grant from the Federal Government body, the Australian Renewable Energy Agency (ARENA).
The main downsides with wind and solar power are that they are unpredictably intermittent and difficult to modulate into a large interconnected power grid. Battery storage is not yet able to store power long enough to provide reliable continuous baseload power to cities.
When wind and solar generators are running they produce cheap power, but storage is problematic.
The key to the economics of the new hydrogen technology is that it can harness the excess cheap power from renewable energy plants to produce the hydrogen, which can then be injected directly into the existing gas network for industries, businesses and consumers.
As ARENA noted last week, there will be an increasing fleet of renewable energy generators in the future. When it is windy and sunny, these plants are likely to generate excess power at very close to nil marginal cost. South Australia already has 40% capacity in wind and solar plants so it is the logical testing ground for the new ‘power to gas’ trial.
ARENA Chief Executive Ivor Frischknecht said the Kidman Park trial would begin by aiming to inject 10% hydrogen into the gas network (in much the same way as ethanol is added to vehicle fuel to make the ‘E10’ product available at petrol stations).
“Some experts recently suggested levels closer to 30 per cent are viable to supplement our gas needs,” Mr Frischknecht said.
Federal Minister for Environment and Energy Josh Frydenberg described the project as a significant leap forward with enormous potential.
“It is the culmination of years of research at Monash University (Victoria) and the University of Wollongong (NSW),” Mr Frydenberg said.
The molten salt concept uses solar energy to heat a form of salt which can store that energy for a period and provide a thermal source to heat a steam turbine to create electricity.
A plant based on this molten salt thermal power concept is in place in the USA, in outback Nevada.
According to Adelaide’s In Daily publication, the same company which has gained Government approvals to build the SA molten salt plant, Solar Reserve, has had difficulties with its Nevada plant.
A structural fault at the $ 1 billion Crescent Dunes facility caused it to go offline for eight months, from last October.
Crescent Dunes is touted by SolarReserve as “the first utility-scale facility in the world to feature advanced molten salt power tower energy storage capabilities”.
The same technology, with a larger output, is planned for a site 30km north of Port Augusta, according to the SA Government. However, the State Opposition says contracts have not yet been concluded.