What does the hydrogen plant consist of?
The hydrogen plant consists of a dedicated 704kW solar farm, 348kW electrolyser, hydrogen compression and storage, and 100kW fuel cell.

Where is the plant be located?
The hydrogen equipment is located at the existing Denham power station on Dampier Road and will fit into approximately 400m2. The dedicated solar farm is located on a new site adjacent to the wind farm and Monkey Mia Road.

How does the plant work?
The process starts with the electrolysis of water, where electricity that is generated from the dedicated solar farm is used to “split” water into oxygen and hydrogen gas.

The produced hydrogen, which is a low density gas, will be pressurised and stored.

To create electricity, the hydrogen gas is passed through a fuel cell and combined with oxygen. The reaction between hydrogen (H2) and oxygen (O2) in the fuel cell produces electricity and water vapour.

Does the electrolysis process use ocean water? If not, what water source will be used?
Mains water will be used as the base water source, not ocean water.

Electrolysis requires purified clean water. To achieve the required standard, mains water will pass through a reverse osmosis system before supplying the electrolyser.

How much water is used in the process?
The process to convert water to electricity uses an average of 1,370 litres per day, which is just above the average daily household consumption of water in Western Australia.

Water will also be utilised for cooling the hydrogen equipment, but the overall daily consumption of water will not exceed the average consumption of four households.

Will the hydrogen be produced onsite in Denham or will it be transported in?
Hydrogen will be produced, stored and converted into electricity via a fuel cell at Denham’s existing power station site.

Why did you choose to build the plant in Denham?
Denham was chosen as a site for the demonstration plant due to a number of factors, including the existing wind farm, the Horizon Power-owned power station and good site access.

Why is Horizon Power refurbishing the power station rather than replacing or relocating it?
Horizon Power has committed to achieving grid-based renewables across 100% of our systems by 2030. This means that building a new diesel-generated power station in Denham would be an expensive short-term solution for delivering power to Denham, and would further delay opportunities to increase renewable power generation options for the town.

Will the hydrogen demonstration plant provide a more reliable power supply than the existing power station?
No. However, the project will test if the plant provides a more reliable power supply than the current intermittent renewable power supply options (like wind and solar). If it does, this will allow renewable energy to replace baseload diesel generation in the future and reduce carbon emissions by 335 tonnes per year.

Why does the power station upgrade still rely on diesel?
Solar and wind power currently need to be stored for when the sun isn’t shining or the wind isn’t blowing, and to cover the intermittency of this power.

At this point in time, it would not be economically viable to power Denham solely from renewable energy.

However, the hydrogen demonstration plant will provide valuable information on whether this technology can use excess renewable power to provide baseload power.

In addition, we recognise the community’s interest in renewable energy and commit to reducing the carbon emissions and increasing the amount of renewable energy generated in the region over time.

What is the future of the wind farm?
Horizon Power has recently taken ownership of these assets and intends to run them until their end-of-life, with future refurbishment or replacement options to be investigated.

What are the advantages of using hydrogen in electricity generation?
Hydrogen is the most abundant element in the universe. It is lighter than air, colourless, odourless and non-toxic.

Hydrogen can be safely produced from water using a process called electrolysis, and is a clean carbon-free fuel, which only produces water when used to generate electricity.

Is hydrogen a safe fuel?
Like natural gas, hydrogen is a combustible fuel, but it is lighter and more easily ignited.

In WA, hydrogen was used in town gas supplies for many years before the introduction of natural gas in the 1970s. Hydrogen has also been used safely for energy in countries such as Japan, and in the space industry, the electronics industry, chemical manufacturing and metallurgical applications.

The safe use of hydrogen today is supported by decades of use and the development of safe practices shared among the global community.

How will safety be managed on the plant?

The project will implement a safety framework appropriate for hydrogen production and storage, including:

• Rigorous application of Australian standards, international standards and best practice guidelines developed for high pressure hydrogen.
• Completion of hazard and risk analysis reviews of design, construction, commissioning and operation.
• Project personnel and suppliers experienced in implementing renewable hydrogen projects.
• Monitoring of plant operating conditions, hydrogen detection and emergency fail safe shutdown systems.

Will I be able to hear or smell the hydrogen plant?
The hydrogen plant will be located on the existing power station site and is not expected to increase the noise levels from the site.

There will also be no smell associated with the plant as hydrogen is odourless.

Why can Horizon Power install a solar farm but we cannot put solar on our roofs?
Too much unmanaged solar output in the power system can cause power system instability and create issues with power supply quality and reliability.

When our solar farm is installed, it will be integrated into the power station control system so that its output can be turned down when there is too much solar output in the system. A large battery system will also be installed to minimise the impacts of the solar power intermittency during cloud events.

We do not currently have the ability to control the output of small customer solar systems. Hosting capacity limits are set to safeguard the quality of electricity supply within each community and work by setting a limit on how much rooftop solar the local electricity systems can safely accommodate.

Will more renewable energy reduce our power bills?
No. The tariffs paid by Denham’s customers are the same as those paid across the state under the Uniform Tariff Policy. This is much lower than the actual cost of generating, distributing and retailing electricity.

The State makes this possible by subsidising the price of electricity to ensure no customer in regional or remote Western Australia pays more than a customer in the Perth metropolitan area.

The increase of renewables will assist Horizon Power to reduce the overall subsidy required from the government, thereby lessening the burden on taxpayers and the State.