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A number of people have contacted me after the remarks of Saul Griffith on television and in print media that have been reported as an attack on green hydrogen. I have responded individually but thought that it might be good to also do so publicly. By Paul Hodgson.
The bottom line is that I agree with Dr Griffith: let’s electrify everything! Now, I know that media wants to simplify things and make it into a fight. I have close experience of the so-called ‘Climate Wars’, particularly in my roles as Senior Adviser to the Australian Climate Change, Industry and Innovation Minister, as General Manager for National Energy Resources Australia (NERA) and as Interim CEO of the Scaling Green Hydrogen CRC over the past decade.
However, the opportunity for Australia is so great and so easily squandered by faux division. According to Geoscience Australia, “Australia receives an average of 58 million petajoules of solar radiation per year, approximately 10,000 times larger than its total energy consumption.“
Australia leads the world in residential rooftop solar with more than one in four households fitted with a rooftop photovoltaic (PV) system. A 2019 report, How much rooftop solar can be installed in Australia?, commissioned by the Clean Energy Finance Corporation and Property Council of Australia, and prepared by the UTS Institute for Sustainable Futures, APVI – Australian PV Institute and UNSW, found that Australian rooftops could support 179 gigawatts (GW) of solar PV, with an annual output of 245 terawatt hours (TWh), more than the current consumption in Australia’s national electricity market (NEM).
A combination of new storage, transmission, grid management technology, business models and other innovations can make this happen along with the mining, minerals processing, manufacturing, installation, operations and recycling required, much of which can also be undertaken in Australia. According to the International Energy Agency (IEA) in 2021, $US 27 trillion of new solar panels, wind towers, battery packs, electrolysers and fuel cells will be required between now and 2050. In the same year, the International Renewable Energy Agency (IRENA) estimated that 43 million jobs will be created in renewables by 2050. Clearly there are great opportunities for Australia in generating renewables.
I haven’t even mentioned Australia’s other world-leading renewable energy assets such as wind (both onshore and offshore), tidal, wave, bioenergy and geothermal but it is fair to say that we have world-leading potential when it comes to renewable sources of energy.
CSIRO and the Australian Energy Market Operator (AEMO) also keep confirming that wind and solar are the cheapest electricity, even when considering additional integration costs arising due to the variable output of renewables, such as energy storage and transmission. So, so far so good.
However, let’s see Australia’s current energy resource production and consumption. In Australia, in 2020-21 we produced about 20,000 petajoules (PJ) of energy resources, mainly coal and gas, and export three-quarters of it. We import about 1,500 PJ of mainly refined oil products. Exporting this much makes us a 400% energy economy.
If we wanted to replace all of this fossil fuel production and consumption in Australia, it might take about 5,500 TWh of renewable electricity. Certainly doable in Australia but about thirty times the size of our existing NEM. The Net Zero Australia draft report suggest we may need forty times the capacity of our existing electricity grid in Australia by 2050. With our vast energy resources, Australia has a responsibility to continue to export energy to existing trading partners and our vast renewable potential means that we can help the world decarbonise beyond our own shores.
So where does green hydrogen come in? Green hydrogen is produced by passing renewable electricity through water (H2O) to separate the hydrogen from the oxygen. This process is called electrolysis and Australia’s largest current operating electrolyser is a 1.25 MW Siemens PEM unit installed for Australian Gas Infrastructure Group (AGIG) at Tonsley in South Australia. Once burnt as energy, the hydrogen releases only water vapour, making it a potential zero emission fuel source (assuming zero emissions throughout the supply chain).
In a country like Australia, with vast access to renewables (predominantly solar and wind), hydrogen and its derivatives may play a smaller part in the electrification story than in other parts of the world. For many applications now energised by coal, oil or gas, renewable electricity will likely be the cheapest alternative.
However, direct electrification won’t be able to replace fossil fuels in all applications, regions and even seasons. In Australia, it may be somewhere between twenty and thirty percent of final energy demand. In other parts of the world it could be much higher.
Here are a few examples:
1. Some countries do not have sufficient access to their own renewables and will want to import at least some to meet their needs. While high voltage direct current (HVDC) cables may link renewables between countries, it is likely that a gas or liquid carrier of green electrons will be required. Geopolitical and energy security considerations may also play a part in favouring shipments arriving regularly from various sources rather than putting ‘all your eggs’ in one HVDC connection. Green hydrogen will be the initial chemical carrier of green electrons but may be converted into green ammonia, green methanol, methocyclohexane (MCH) or other liquid organic hydrogen carriers (LOHCs).
2. Some mobility applications may be too long and require too much load to be battery-driven, think long haul aviation, shipping and to a more varied extent, rail, trucks and buses. It is worth noting that battery electric (BEV) and hydrogen fuel cell electric vehicles (FCEVs) are both based on electricity.
3. About 80-100 million tonnes of hydrogen is currently produced each year, predominantly using natural gas in a process called SMR and for input into ammonia production and petrochemical refining. Ammonia-based products such as agricultural fertilisers will still be required, requiring green hydrogen to decarbonise. Green hydrogen will be required to refine metals and biofuels, even in the absence of the refining of fossil fuels.
4. As we see a reduction in oil production, there are a lot of plastics, polymers and other oil-based products that are going to disappear from our supply chains. Electricity-derived chemicals may be needed as a base to replace the production of a range of chemicals and materials that we use today.
Now we are doing all of this with one predominant goal in mind – the quickest and least cost global reduction of carbon emissions into the Earth’s atmosphere. I tend to think that there are four main tools at our disposal:
1. Energy efficiency
2. Renewable electrification
3. Green chemicals and fuels
4. Carbon capture, utilisation and storage
Once you have made your process as energy efficient as possible, you use direct renewables and then, if needed, you look to green hydrogen as a carrier of that renewable energy into chemicals and fuels. Each storage, conversion and transmission stage of renewables adds financial and material costs and involves energy losses. It will make little sense to add those costs and losses if they are not necessary.
In the Scaling Green Hydrogen CRC, we are bringing together a diverse group of leading organisations to build a strong foundation for the role that green hydrogen can play in extending electrification into the remaining areas of the economy we need to decarbonise. Our estimate is that one terawatt of electrolysis will be needed in Australia by 2040, which is 800,000 times the size of the existing operational unit at Tonsley.
The sun keeps shining, the wind keeps blowing and the water keeps moving. We need to capture as much of this consistent flow of renewable energy as we can, on rooftops, on ground and offshore for Australia to reach its potential. Green hydrogen is part of electrification, helping renewables finish the job of decarbonisation.
By: Paul Hodgson ACEcD, Interim Chief Executive Officer, Scaling Green Hydrogen Cooperative Research Centre
This article originally appeared at Paul Hodgson’s Linkedin page, and has been republished with permission.
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