What is hydrogen?
Hydrogen is the most abundant element in the universe, though it is not found naturally on Earth.
Hydrogen must be extracted from other sources. In its purest form, hydrogen is a non-toxic colorless and odorless gas. Hydrogen (when used as a fuel), like electricity, is an energy carrier rather than an energy resource.
What are some of the uses of hydrogen?
Hydrogen can be produced as a gas or liquid, or made part of other materials, and has many uses such as fuel for transport or heating, a way to store electricity, or a raw material in industrial processes.
When it is produced using renewable energy or processes, hydrogen becomes a way of storing renewable energy.
Hydrogen energy can be stored as a gas and even delivered through existing natural gas pipelines.
When converted to a liquid or another suitable material, hydrogen can also be transported on trucks and in ships. This means hydrogen can also be exported overseas, effectively making it a tradable energy commodity.
How is hydrogen extracted?
Hydrogen is a rare element which means it needs to be manufactured. The energy and materials can be provided by either renewable power and water, or coal and gas.
There are three methods to extract hydrogen. One is electrolysis that uses electricity to 'split' water, which can be powered by renewables in an emissions-free process and is known as 'green hydrogen'.
"Lately electrolysis has attracted a lot of attention because the energy associated with electrolysis is high. If you have a renewable energy source to cover that energy penalty then electrolysis is the best way of doing this," University of Newcastle energy researcher Professor Behdad Moghtaderi said.
Thermochemical reactions drive the other two methods. One uses gas and the other uses coal or gas, and for either to be a clean energy source they require carbon capture and storage to stop the emissions from the fossil fuels entering the atmosphere. These are known as 'blue hydrogen'.
What is the Australian government's hydrogen policy?
The government announced $300 million for the Clean Energy Finance Corporation last year and instructed it to invest in new hydrogen energy projects - including those powered by fossil fuels. In addition, $70 million has been committed for green hydrogen project development through the Australian Renewable Energy Agency.
It has also committed $70 million to help develop a regional hydrogen export hub.
Advantages and disadvantages of hydrogen
Hydrogen is a rich source of energy which is in abundant supply.
- Clean energy source
When we burn hydrogen no harmful byproducts are released into the atmosphere. Once hydrogen has been used as an energy source, it can be converted to drinking water.
Hydrogen does not cause damage to human health unlike nuclear energy or natural gas.
- Hydrogen energy is highly efficient
Hydrogen is incredibly dense in energy and is able to provide a lot of power. It is three times more powerful than most fossil based fuel sources so less hydrogen is required to perform the same tasks. This is why hydrogen is used in space exploration to fuel spaceships, aeroplanes, boats, cars and fuel cells.
Because of its high energy content, hydrogen gas is a highly flammable and volatile substance which makes it a risky fuel to work with.
- Expensive to produce
Both steam-methane reforming and electrolysis are expensive processes which prevents a lot of countries from committing to mass production. Research and trials are in process to try and discover a cheap and sustainable way to produce enough hydrogen without contributing more carbon into the atmosphere.
- Difficult to store
Hydrogen is a much lighter gas than petrol which makes it difficult to store and transport. To be able to store it we need to compress it into a liquid and store it at a low temperature. The high amounts of pressure needed to store hydrogen makes it a difficult fuel to transport in large quantities.
- Can be dangerous
Hydrogen is extremely flammable which makes it a dangerous fuel if not handled correctly. There is also no smell to hydrogen so sensors are required to detect leaks.
"Because of hydrogen's reluctance to ignite mixtures of hydrogen and oxygen are often stored together on space programs. Because there is no catalyst for ignition they are perfectly safe," Professor Moghtaderi said.
Why is the Hunter a good location for a future hydrogen hub?
The Hunter has access to the high quality renewable energy needed to make hydrogen cost effectively. It is the hub of the NSW power grid, and can draw a mix of solar and wind energy from the north, south and west of the state.
"Other regions may say we have land as well but in this region we also have expertise at the CSIRO energy centre, the University of Newcastle and heavy industry. We have a number of energy sinks, such as Tomago Aluminium," Professor Moghtaderi said.
"These advantages combined with very good infrastructure for distributing electricity makes the Hunter a unique region to deploy energy from hydrogen."
What will Australia's energy mix look like in a decade's time?
"I believe in the future we will have a heavy reliance on renewable energy given that we have an abundance of land and solar energy," Professor Moghtaderi said.
"Renewable energy will be a significant part of our energy mix. Especially for the export market we will have hydrogen production. Hydrogen could be dominant in the transport sector, not necessarily in the inner city short distance but for interstate or long distance travel.
"In 20 years we might have solved the problem of using renewable fuels and using hydrogen for air travel."
Future of coal?
"I see the future of coal to be very bright but not in energy production. Coal is a very valuable material, we can do a lot of other things with it," Professor Moghtaderi said.
"In our centre (University of Newcastle Institute for Energy and Resources) we have researchers who are working on producing carbon fibre from coal. I would see the application of coal in the future in this sort of area, advanced materials and chemicals."
"That transition will need an element of carbon capture and sequestration to minimise the emissions.
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