Projects
Hydrogen
Significant potential exists for the nascent hydrogen industry to be a major contributor to the Western Australian economy and to the wellbeing of all Western Australians, providing essential energy and jobs as we transition to a carbon free future.
Hydrogen is recognised as a key component for decarbonisation globally. Hydrogen storage is of vital importance to underpin the hydrogen supply chain. Whilst much research is being undertaken on hydrogen storage as compressed gas, liquid form, and metal materials or solids, there has been little research into large-scale storage of hydrogen.
SHEA are also researching other options and projects including carbon storage and capture.
underground hydrogen storage
The Drivers
Although in its infancy, underground hydrogen storage in depleted oil and gasfields and in saline aquifers (geological storage – UGHS) is anticipated to be no more difficult than existing gas storage or CO2 storage in a practical sense. Although pure hydrogen storage in salt caverns is practiced in some international locations, hydrogen storage in depleted gas or oil fields has not been done anywhere in the world. Some preliminary studies are indeed promising regarding the possibility of using the depleted fields for hydrogen storage, but further research and experimentation is required.
The increasing contribution from the uptake of residential solar, industrial solar and wind energy (variable renewable energy - VRE) in the electricity grid in Western Australia, is following a similar path to that seen in California, and is creating a substantial mismatch between supply and demand. In addition, hydrogen generated from methane-reforming, and consequential carbon capture and underground storage (CCUS) , can also be stored. Synergystic development of UGHS and CCUS is possible in some circumstances.
International studies have identified the following advantages for large scale hydrogen underground geological storage:
- Hydrogen energy storage is an ideal match for renewables of all scales, especially large-scale wind.
- Hydrogen with renewables is effective for reducing greenhouse gases from power generation.
- Underground storage offers opportunities to store H2 because of large capacity and competitive cost.
- Stationary hydrogen and fuel cell applications complement the electric system across a spectrum of sizes, from residential and communities, distributed generation and load and source - leveling .
Underground Hydrogen Storage
The Economics
In their 2018 paper, Kharel and Shaban[1] presented ‘a case study of using hydrogen for large-scale long-term storage application to support the then existing electricity generation mix of South Australia, which primarily included gas, wind and solar. They found that a Hybrid battery-hydrogen storage system was more cost competitive with unit cost of electricity at US$0.626/kWh compared to battery-only energy storage systems with a US$2.68/kWh unit cost of electricity.’ Kharel and Shaban’s research further found that ‘the excess stored hydrogen can be further utilised to generate extra electricity.
Further utilisation of generated electricity can be incorporated to meet the load demand by either decreasing the base load supply from gas in the present scenario or exporting it to neighbouring states to enhance economic viability of the system. The use of excess stored hydrogen to generate extra electricity further reduced the cost to US$0.494/kWh.’
However, the Kharel and Shaban study considered hydrogen storage in vessels and not underground geological storage. It is anticipated that UGHS in depleted fields and saline aquifers will be even cheaper.
[1] Kharel, S.; Shabani, B. Hydrogen as a Long-Term Large-Scale Energy Storage Solution to Support Renewables. Energies 2018, 11, 2825. https://doi.org/10.3390/en11102825
Underground Hydrogen Storage
Electricity from Renewable Sources
With the uptake of residential solar power, industrial scale solar power, and wind farms in Western Australia and around the world, a new phenomenon is emerging. This occurrence is being caused by the shifting energy demands of the population in the way electricity is generated and consumed through the grid.
As the sun goes down (and much of the population returns home from work), a sudden spike in the need for grid electricity occurs. This is best illustrated in the graph right. The graph of power production over the course of a day that shows the timing imbalance between peak demand and renewable energy production. The large part of the curve shown in ‘orange’, and which has been falling during the middle of the day, is due to the uptake of residential solar. Whilst the example in from California, the same effect is occurring in WA. Used in utility-scale electricity generation, the term ‘Duck Curve’ was coined in 2012 by Karen Edson of the California Independent System Operator[1].
[1] Wikipedia https://en.wikipedia.org › wiki › Duck_curve
A weekly snapshot of the WA electricity supply/demand is shown above. The ‘Duck Curve’ is readily evidenced in WA. ([1] opennem.org.au)
The regulator responsible for managing the Wholesale Electricity Market (WEM) for the connected system in WA is really only considering punitive mechanisms to manage the load. It is SHEA’s contention that there is a remarkable opportunity here to manage the system to incorporate hydrogen generation throughout the day by running the entire system at maximum capacity, and generating and storing hydrogen from electrolysis.
In principle, UGHS could offer several services to the power system:
- By storing surplus electricity from intermittent renewables such as solar and wind, or indeed allowing the system to balance such that the system ran at full capacity for much of the time, UGHS could provide periodic and seasonal storage, which would enable adjusting the output of generation facilities to the demand of grid operators and ultimate consumers.
- For renewable energy sources connected to the transmission network, UGHS can potentially balance the grid by minimizing the need to curtail excess generation that would normally result in an overloaded and unstable grid. Instead, surplus power could be stored for later conversion back to electricity when the transmission system is available, or exported to eith domestic or international markets.
- UGHS could facilitate grid integration of stranded renewables. Indeed, when the extension of the power grid is not possible for technical and/or economic reasons, stored hydrogen could be delivered to the end user through trucking or pipelines.
- Stored hydrogen does not suffer from conversion losses suffered by other methods of storage, such as ammonia.
[1] Source: https://opennem.org.au/energy/wem/?range=7d&interval=30m