The wind turbines of Scott Base

By Rebecca Priestley In Science

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7th January, 2012 Leave a Comment

Photo Antarctica New Zealand

“Fuel is life in Antarctica,” Jonathan Leitch told me at Scott Base last month. Leitch is in charge of asset management at the permanent New Zealand station that sits near the end of Hut Point Peninsula on Ross Island. This volcanic island, dominated by Mt Erebus, is the most populated part of the frozen continent: Scott Base can sleep up to 85 people, and at the American McMurdo Station, just over the hill, the summer population can reach more than 1200.

For decades, it’s been fossil fuel that has provided the heat to keep people alive here at latitude 77° 51′, where temperatures hover around freezing point in summer and drop to minus 50°C in winter. It powers the aeroplanes, helicopters, Hägglunds and skidoos that take scientists and their gear into remote field camps.

It has powered the reverse-osmosis plants that turn seawater into drinking water, the waste water plants that treat the sewage, and the hitching rails that keep vehicles warm in the cold air. No wonder, then, that most of the freight (by weight) that is shipped to Ross Island is fuel for generators, space heaters and vehicles.

But things are changing. In a new project initiated by Antarctica New Zealand, up to 60% of Ross Island’s electrical energy is now provided by wind power. In early 2010, Meridian Energy installed three 330kW wind turbines – locally referred to as “the three sisters” – on Crater Hill behind Scott Base. Now they sit on the horizon between Scott Base and McMurdo, their gentle whirr adding to the soundscape of helicopters, monster trucks and the occasional seal roar.

“It’s been a huge success,” says Leitch. When the wind is blowing, the turbines provide all Scott Base’s electrical energy, with excess sent to McMurdo Station. When the wind stops, McMurdo’s generators provide electrical energy to Scott Base. “There’s been a change in thinking,” says Leitch. “Scott Base and McMurdo Station used to be run separately, but for generation and consumption of power we’re now one.” It’s no longer the New Zealand network and the United States network: it’s the Ross Island network.

Ross Island has the same issues with fossil fuel as New Zealand – it’s expensive, it has to be shipped from the northern hemisphere, and it releases CO2 into the atmosphere. But because of Antarctica’s remote location and pristine environment, these problems are compounded. In the heroic age, before the Antarctic Treaty protected the continent’s wildlife, explorers supplemented imported fuel by burning seal or penguin blubber. When Sir Edmund Hillary drove from Scott Base to the South Pole in 1958, he cooked food and heated his tent with paraffin and kerosene and powered his Massey Ferguson tractor with petrol.

These days, aviation fuel, which does not begin to congeal until minus 50°C, is used for Ross Island’s main generators and aircraft. Portable field generators and vehicles run on Mogas, a low octane unleaded petrol. By allowing Scott Base to shut down its main generators, the wind farm has so far resulted in collective United States and New Zealand fuel savings of more than 450,000 litres a year. But it’s not Ross Island’s first attempt at an alternative energy source.

In the summer of 1962, the Americans installed a 1.8MW nuclear power station, run on a mix of uranium-235 and uranium-238, at McMurdo. But the McMurdo reactor – dubbed “nukey-poo” by its New Zealand neighbours – was plagued with problems and in 1967 plans to add nuclear power stations at the American bases at Byrd Station and the South Pole were shelved. After a 1972 inspection revealed a crack in a water tank used to provide radiation shielding, the McMurdo reactor was decommissioned.

The dismantled reactor, along with more than 70 tonnes of soil contaminated with radioactive isotopes such as caesium-137, was removed and shipped back to the United States via Lyttelton.

That was Antarctica’s only foray into nuclear power, but Ross Island’s wind turbines are not the first on the continent. At Australia’s Mawson Station, in East Antarctica, two wind turbines supply up to 70% of the station’s electrical energy. Small wind turbines power some remote field stations. And in the Antarctic summer, solar power provides energy to some field camps and monitoring stations.

Mogas generators are still used in most short-term field camps, but Leitch says Antarctica New Zealand’s plan is to make the portable field units more energy-efficient. The new generation of huts will have better insulation, glass doors to capture the solar gain of the 24-hour summer sunshine, and either more efficient diesel generators or solar or wind power generators.

Fossil fuel still plays a big role in Antarctica. The fuel tanker is expected to arrive at McMurdo this month. An icebreaker will travel ahead of it, cutting a channel through the sea ice to let the tanker through to the ice pier at McMurdo. Once it arrives it will take two days to pump the fuel from the ship to the tanks at the base of Observation Hill above McMurdo.

But dependence on fossil fuel is changing. With some more turbines, along with new plant to store water and energy when the wind farm is operating at full capacity, and a switch to electrical boilers and cookers, wind could one day soon supply all the island’s electrical needs.

Rebecca Priestley travelled to Scott Base on Antarctica New Zealand’s media programme. www.antarcticanz.govt.nz.

SCIENCE Q&A

Question: David Smith of Auckland is curious about the flow of bath water down a plug hole. “More than three-quarters of a century ago my mother told me that in the Southern Hemisphere water spirals out of the bath in the opposite direction to that in the Northern Hemisphere. Is this true? Why? What does it do at the equator or at either pole?”

Answer: I knew this had something to do with the Coriolis force, so I asked Erick Brenstrum, severe weather forecaster with MetService, to answer the question. “The short answer is yes, but,” says Brenstrum. “And the but is that to demonstrate this effect you need to have a circular bathtub several metres in diameter. The water has to be left standing for a day or more so any movement left over from filling the bathtub has died away. You need a plug in the centre, one that can be removed from underneath so that you don’t introduce any movement by sticking your hand in. Then, as the water goes down the plug hole, it will eventually start to rotate clockwise in the Southern Hemisphere and anticlockwise in the Northern Hemisphere.

“So why? Because the water on the side of the bath nearest the equator is moving eastwards faster than water on the other side. As that water is drawn into the centre of the bath, this initial rotation accelerates. The place that’s hardest to make it happen is at the equator. If you move 100m either side of the equator, you get less than a millimetre closer to the axis of rotation of the Earth. But if you’re at the South Pole, and you’ve got a bathtub 2m wide, when you move 1m away you’ve actually moved almost the whole metre away from the axis of rotation. So the effect should work really well near the poles.”

7th January, 2012 Leave a Comment

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