One of the first things that immediately captures the eye when arriving at Mawson station are the two Enercon E-30 turbines that make up the skyline.
Each turbine is capable of producing 300 kW of power. They were installed in 2003 and now make a significant contribution to the station’s power requirements.
Due to the changing sea ice conditions around Mawson station, this year the Aurora Australis was unable to reach Horseshoe Harbour to deliver the full 450 000 litres of fuel required to run Mawson station for the year. This forced the AAD to fly in a limited amount of fuel to see us through our season, which means there will be a greater reliance than ever on these machines to provide station power and conserve the fuel for the year ahead.
Since installation the wind turbines have produced a combined 17 010 megawatt hours of electricity, saving the AAD approximately 5 million litres in diesel, making it one of the most environmentally friendly bases on the continent.
The Mawson wind turbine system ranks among the world’s most innovative and is capable of providing 600 kW of renewable power. The AAD worked closely with German turbine manufacturer Enercon and the Australian company PowerCorp to install these turbines and the associated computerised powerhouse control system. It is a design that was so successful that it was selected for the Ross Island wind farm installation of Scott base and McMurdo Station when they were looking for wind power alternatives in 2008.
The Enercon E-30 turbine is a variable speed, 300 kW machine without gearboxes, mounted on a steel tower 30 m above the ground. The PowerCorp station management system (SMS) controller is vital to the efficient operation of the Mawson wind farm and optimises the instantaneous wind resource and diesel generator outputs to that of the station load.
One diesel generator is required to run at all times to aid the frequency control and provide “spinning reserve” if there is a sudden lull in the wind. In addition to this control, Mawson station makes use of a boiler grid interface (BGI) where the electric boiler power electronics acts as a regulator to absorb the power fluctuations common on small wind turbine grids. This is a system unique to Mawson station.
Another common term when assessing the effectiveness of a wind farm is “wind penetration” (the ratio of wind-provided power to diesel power), which is usually between 55–60% for the year at Mawson station and has the ability to save in excess of 200 000 litres of diesel in that time. It is the goal of the current Mawson engineering team to make this percentage as high as possible for this season. We hope to achieve this through a mixture of Kingston-introduced power saving initiatives, running tighter power controls and responding to turbine breakdowns in the quickest possible manner.
Since we have been at station we have recorded wind penetration of 81%, 62% and 57% for the months of April, May and June respectively. This highlights the need for the correct wind conditions for optimal performance, because while the wind turbines have a reduced capacity at low winds they also ramp down power output in higher wind conditions, having an optimum working range between 16–25 m per second. These are conditions that have been eluding us for the last two months but we wait and hope for better conditions (and fuel savings) in the months to come.
Aidan Heather — Electrician and proud Kiwi