The challenges facing the national energy market highlight the need for new, sustainable solutions and the engineering ingenuity required to bring new ideas to market.

Despite a wealth of natural resources, particularly fossil fuels, come Winter 2022, Australia is amid an energy crisis. Electricity generation prices are at a staggering $300 per megawatt hour – triple the price at the start of the year.

Citing crippling costs and reduced profits after the Australian Energy Market Operator (AEMO) placed a cap on wholesale prices, some power generators have been withdrawing power supply from the grid. AEMO can direct generators to increase supply with compensation for their losses, but it didn’t prevent the issuing of notices flagging potential blackouts in Victoria, Queensland, NSW, and South Australia.

While Australia’s energy market is notoriously complex, two key drivers of the price hikes are exposure to volatile fossil fuel prices, particularly with sanctions on Russian thermal coal, and ageing coal-fired plants are nearing the end of their service life. In addition, up to 25% of coal generation is offline for maintenance or unplanned outages.

While wind, solar, and hydro electricity generation, coupled with large-scale battery storage projects, get the headlines, SOTO engineers have been lending their expertise to projects exploring innovative ways of harnessing renewable energy.

Making waves in energy generation

Just off the shoreline at the town of Grassy on Tasmania’s King Island sits an unusually shaped object. Its oblique shape and little to no hull make it look like some experimental naval vessel that ran aground, and only its bridge pokes above the waterline. Yet, watch long enough, and you can see the vessel is floating, gently bobbing with the back and forth of the swell. The mysterious craft is a 200kW wave-powered turbine generator owned and operated by Wave Swell Energy (WSE).

The unit started supplying power to the grid in June 2021, enough power from more than 200 homes, a significant achievement and world-first for this type of energy generation. WSE has pioneered a form of energy generation from wave energy based on a technology called oscillating water columns. The technology is based on the concept of a blowhole, where the generator captures waves in the chamber, forcing air upwards, which then spins a turbine to produce clean, renewable energy.

The lack of moving parts makes this concept different from other forms of wave energy technology. Moving parts break and require regular maintenance, which is difficult and costly in deep-water environments. With no moving parts in the water column, there are also no oils or other water contamination. The blowhole design means the turbine spins only when the wave forces air up the chamber and rotates in one direction only. The chamber design gathers maximum energy from each wave intake, while a single-direction turbine rotation reduces complexity and improves reliability. Therein lay the engineering challenges that SOTO was enlisted to help solve.

Design challenges

“A turbine for a specific purpose is easy to get off the shelf, but for something bespoke like we have with the Wave Swell turbine, this hasn’t been done before,” says Project Engineer Frank Soto Jr, who worked with Wave Swell to solve the challenge of a unidirectional turbine. “The main parts of a turbine, the generator, the rotor, and the stator, are standard, but to get the specific results based on the required functionality for this design, we had to come in and help provide that level of detail.”

A secondary challenge that has been making headlines in Australia for some time is skills and capabilities in the domestic manufacturing industry. With decades of decline, critical skills have been lost, increasing Australia’s reliance on imports, and reducing capacity for innovation. Some parts of the design required rethinking because no one in Australia had the expertise and tools to fabricate the parts.

“In particular, the nose cone design was intended to dissipate the air through the turbine. The client’s desired solution was using metal spinning, but very few people do that in this country, and not to the size we needed. The only option would have been to offshore it to somewhere like Germany or the US, but instead, we designed a fibreglass cone, which any boat manufacturer could do with the right moulds.”

World recognition, local achievement

Known as UniWave200, Wave Swell’s unit is working swimmingly well, consistently supplying power to the Tasmanian grid. The project’s success has not gone unnoticed, winning the Fire (Energy Generation) category in the 2021 Energy Globe Awards. Mr Soto says the project highlights the need for people to take calculated risks on innovative ideas and enlist the people with the vision to turn ideas into reality.

“When something unique like this comes along, it’s the excitement of what it represents and the challenge of solving problems. Engineers are problem solvers by nature,” he says. “It’s really an achievement for the region. Much of it was manufactured right here in the Illawarra. The only parts that weren’t were the turbine rotor itself and the stator. However, we partnered with a local business, Lucchini Engineering, who are specialist machinists. They worked in collaboration to assist with the fabrication and assembly of it in Melbourne.

“Having that expertise within the Illawarra and achieving the final assembly and shipping the turbine from here, that’s where the achievement is in this project. The region has the capability and the skills to deliver on game-changing technology like this.”