Control for solar research project

Researchers at the Australian National University in Canberra have developed breakthrough technology that makes large-scale, solar thermal power generation commercially viable. And a Yokogawa PLC is playing a critical role.
The university has been involved in solar thermal power research for decades and is now conducting the final testing of its innovative, second-generation Big Dish solar thermal concentrator. The device has been built in the university grounds with support from corporate partner Wizard Power.

To work efficiently, the mirror-covered dish needs to rotate and change angle during the day as the sun changes position, and for that a small control system is needed. Yokogawa successfully presented the case for its FA-M3 programmable controller and won the order.

The dish concentrates the sun’s rays onto a receiver mounted at its focal point, providing sufficient heat to split ammonia into hydrogen and nitrogen gases. These gases can be stored indefinitely at ambient temperature until required for use. When power is needed, the gases are recombined in an exothermic reaction, which produces enough heat to generate electricity through a steam turbine.

Because the Big Dish technology stores energy before generating electricity, it is capable of delivering multi-megawatt base load electricity and meeting peak loads on demand 24 hours a day in the same way that coal, nuclear or gas-fired power stations do. It’s emission-free power generation on a large scale.

Once the technology has been fully tested, it will be utilised in a pilot baseload solar thermal power plant in Whyalla, South Australia.

The Whyalla plant will initially have four dishes, each of which will have its own control system and be capable of producing up to 100 kW of electricity. The federal government has supported the project with a $7m grant as part of its efforts to tackle climate change.

There is also interest in the technology because the high temperatures that the Big Dish can achieve - up to 1200 degrees Celsius - make an array of other conversion opportunities possible. These include solar gasification of coal and biomass to produce distillates that can be used as clean transport fuels.

“It’s very exciting for everyone at Yokogawa that our equipment is contributing to a technology that will have such a positive impact on the planet,” Yokogawa Australia Managing Director John Hewitt said.