Guest essay by Eric Worrall
The Australian Federal Government has expedited approval for a $53 billion project and the devastation of 78 Sq KM of wilderness, to produce green hydrogen for an export market which does not exist. All to save the planet.
Green giants: the massive projects that could make Australia a clean energy superpower
Sat 14 Nov 2020 06.00 AEDT
The Asian Renewable Energy Hub would have an energy content equivalent to 40% of Australia’s overall electricity generation
by Adam Morton
Sat 14 Nov 2020 06.00 AEDT
Called the Asian Renewable Energy Hub, its size is difficult to conceptualise. If built in full, there will be 1,600 giant wind turbines and a 78 sq km array of solar panels a couple of hundred kilometres east of Port Hedland in the Pilbara.
This solar-wind hybrid power plant would have a capacity of 26 gigawatts, more than Australia’s entire coal power fleet. The hub’s backers say the daytime sun and nightly winds blowing in from the Indian Ocean are perfectly calibrated to provide a near constant source of emissions-free energy around the clock.
Most of it will be used to run 14GW of electrolysers that will convert desalinated seawater into “green hydrogen” – a form of energy that analysts expect to be in increasing demand as a replacement for fossil fuels in the years and decades ahead.
Though still five years away from construction, the hub vaulted closer to reality in recent weeks after the federal government granted it major project status – a designation that should smooth the approval processes – and the Western Australian government greenlit its first stage.
But most of the energy created will be exported. Because hydrogen condenses from a gas into a liquid only at very low temperatures (about -250C), it will be shipped as green ammonia, which is safer to transport and created by blending hydrogen with nitrogen.
One of the questions hanging over the project will be its cost, but Star of the South maintains it makes economic sense – that the technology is becoming cheaper and the generation patterns of offshore wind will complement, rather than compete with, onshore renewables. It is seeking environmental approval from the Victorian government and waiting on the commonwealth to complete a legal framework for offshore clean energy developments, but has a goal of starting to generate by 2025.
My question – if the “technology is becoming cheaper”, and the market is not expected to exist until 2035, why jump the gun? Why not wait a few years, until the costs come down even further?
The Asian Renewable Energy Hub plan has undergone several radical transformations since its inception. The original idea was an undersea cable to Asia, but this idea seems to have quietly died. Then it briefly morphed into a green hydrogen export facility but now seems to have evolved into a green ammonia production and export facility.
A 2017 CSIRO study suggested round trip efficiency for green electricity to hydrogen to ammonia and back to electricity is 25 – 39%, which means up to 75% of the already hideously expensive renewable electricity is lost just in the conversion process, without even considering shipping and distribution costs.
Ammonia production from fossil fuel sourced hydrogen is a mature industrial process, so you would have to be pretty optimistic to expect significant performance gains from that part of the process.
Any dramatic cost savings will have to come from cost savings in the manufacturing of the solar panels and wind turbines, but there is a limit to how far the price can fall. Wind turbine and solar panel production are very energy intensive industrial processes.
A final straw, somehow the project will need to source vast quantities of water, for washing the solar panels. The dust buildup in the Australian desert has to be seen to be believed. In the dry desert environment static charges build quickly, causing the dust to stick to surfaces. You can’t use unprocessed sea water to wash the panels, because heated brine is corrosive, leaves a residue, and is a very good electrical conductor – short circuits, light obstruction and corroded wiring in one easy package. You can’t use compressed air to clean the panels, because the dust particles are abrasive; compressed air would sand blast the panels. While there is ongoing research into using electrostatic methods to remove the dust, or gently brushing the dust away without water, Chemically pure water remains one of the least damaging cleaning agents.
But in the desert, clean water is a highly constrained resource.
So in addition to desalinating water for hydrogen and ammonia production, the project will need to desalinate vast quantities of water to keep the 78 sq KM of solar panels clean, by giving them a regular wash.
This content was originally published here.