Solar and wind are currently at the fore of the renewable energy race in Australia, but a fierce contender lurks in its oceans.

Australia boasts the world’s biggest wave energy resource, which stands at about 1,800 terawatt hours. The southern half of the continent—Brisbane and Geraldton is said to hold most of it. In context, Australia utilised 248 terawatt hours of energy in 2013-14.

In addition to waves, the daily movement of the tides also works to shift a huge amount of water across the Australian coast, with the technology used to convert tidal renewable energy to electricity considered more mature than other wave converters.

Oceanic renewable power also includes oceanic thermal energy conversion, and energy harvested from large oceanic currents (like the East Australian Current). These two represent the insignificant and less mature technologies with less if any chances in Australia.

Australia is well endowed with abundant energy resources –both clean energy and fossil fuels. So, how do we capture and direct oceanic energy into our homes?

The Current Target

The existing Paris Agreement, and to which Australia became a signatory, focuses on limiting global warming to below 2℃. This calls fordecarbonisation of virtually the entire global electricity systems by 2050.

About 17 terawatt hours of the 248 terawatt hours of power consumed in Australia is generated from large-scale renewable energy technologies, which can be equated to about half of Australia’s ambitious Renewable Energy Target of 33 terawatt hours by year 2020.

To ensure we are on the right track towards meeting the country’s international commitments, a new target of 65% by year 2030 was recently proposed by members of Australia’s Climate Change Authority. This will need a rapid, large-scale transition to the abundant alternative green energy systems.

Solar and wind are emission-free renewable energy technologies that are currently more reliable although other technologies will be required to boost the energy capacity. This will not only enhance the lower emissions energy supply, but will also help overcome the intermittency problem caused by the natural variability of energy resources (such as during winter when the sun doesn’t shine, or when the wind is calm)

Tapping into the sea

Oceanic clean energy technologies such as tidal and wave are promising and poised to contribute immensely to Australia’s future energy mix, and with huge benefits over other energy sources.

Both the tidal and wave energy devices can be deployed offshore (i.e. doesn’t require the limited land space), and are generally out of sight (meaning placed under the surface, adequately offshore and maintains low profile as it can’t be noticeable by the casual observer).

Just like solar and wind, oceanic energy resources also change on a daily basis, although wave energy is only made up of a third of the wind power’s variability. It can also be predicted three times ahead when compared to wind. On the other hand tidal energy can be forecasted over extended time-frames.

These features add to the many advantages of the clean energy technologies portfolio, hence leading to notable investments by the Australian government and other institutions in oceanic renewable energy technologies.

Oceanic energy in Australia

To date, the Australian Renewable Energy Agency (ARENA) has used over AU$44.3 million  to fund about nine oceanic renewable energy projects (two were shut even before completion due to technical and financial challenges). In total, Australia has spent over AD$122 million on oceanic energy.

All the approved oceanic projects in Australia are expected to have an installed capacity of about 3.5 megawatts. The world’s total installed capacity of wave energy projects are actually less than 5 megawatts.

The EU has also invested significantly in wave energy projects, and to date around €185 million (around A$275 million) has been pumped to these projects, which are expected to produce an installed capacity of 26 megawatts by 2018.

Notably, besides tidal energy converters being the most available oceanic renewables in Australia, a top quality assessment of the country’s tidal energy resource is yet to happen.

Nonetheless, there are prospective sites near Tasmania and in northern Australia that have attracted both national and international attention for possible development due to their fascinating resource.

Falling costs

Currently, oceanic energy technologies have high lifetime costs. Until when 10 megawatts of wave energy capacity are installed globally, costs are expected to remain all high at approximately A$500-900 per megawatt hour.

Today, there are about 500 gigawatts of wind energy installed in Australia, and the cost of onshore wind is estimated at A$110 per megawatt hour, the same as coal.

This means that wave energy costs will drop to between A$170-340 per megawatt hour when its installed capacity hits 2 gigawatts. However, the cost shouldn’t be the only performance indicator when it comes to oceanic renewables.

There are several options being pursued in order to combine and integrate design of given infrastructure (like recreational amenities,powering offshore aquaculture, or wave energy capture to be used as a coastal protection mechanism, all poised to reduce relative costs.

Support for a promising industry

Putting oceanic energy generators in our seas, operators, planners and financiers will need more understanding of the amount of energy that is available and where.

Thankfully, ARENA and CSIRO have created the Australian Wave Energy Atlas to provide wave energy resource information as well as all necessary details about the available spatial constraints and electricity infrastructure for deployment. This enables users to identify sites that are more viable for wave energy projects, and eventually simplify the process of acquiring capital and negotiating the approving process.

Even with the attractive qualities of oceanic renewable energy, several challenges still exist. The main advantage of predictability and consistency of ocean energy is likely to diminish if costs remain above those of solar and wind integrated with storage, which can offer similar advantages.

The technological innovations required to manufacture effective energy generation devices at cheaper costs; existing policy and regulatory barriers to future project development; lack of awareness of oceanic renewables and the possibilities they carry; lack of knowledge on the environmental impact of large-scale deployments; as well as the finance mechanisms needed to support this emerging industry.

All these challenges can be overcome only if researchers, decision-makers, manufacturers, and businesses can come together to unlock the great potential of Australia’s oceans.