Can efforts to make Antarctic research stations energy self-sufficient work? E&T puts on a polar coat to find out.
The arguments that are usually made to support the use of clean, renewable energy sources in more 'normal' continents apply also to Antarctica. In fact, when it comes to the coldest, windiest, highest, driest and remotest continent on Earth, the same arguments are considerably amplified.
If locally sourced renewable energy can help bring down the cost of power generation in areas where fossil fuel is easily accessible, in Antarctica (where diesel can only be delivered during the summer, typically once a year via long and tricky icebreaker journeys), the cost advantages of going green are all the more evident.
Similarly, reducing greenhouse gas emissions may seem like the responsible thing to do anywhere on Earth. But in pristine Antarctica, where pollution of any kind is heavily discouraged by the Antarctic Treaty that all nations operating in the continent are subscribed to, reducing your carbon footprint is a matter of principles.
Who would want to be accused of contaminating a continent that holds not only 70 per cent of the planet's fresh water but also probably the key to understanding climate change?
Refuelling Antarctic bases is not only logistically challenging; in many cases it's also a hazardous operation that can lead - and, on occasions, has led - to fuel spills.
In that context, it's hardly surprising that a number of countries running scientific research stations across Antarctica have recently been studying, testing and deploying alternative energy systems to supplement - and, in some cases, to completely replace - their diesel-burning generators.
The first major step was taken by Australia. In the 2002/03 austral summer, the Mawson station, operated by the Australian Antarctic Division, was equipped with two wind turbines supplied by German manufacturer Enercon.
Earlier studies had suggested that Mawson was strategically located to take advantage of the katabatic winds that blow from the inland of the continent. After seven years of consistent operation of the wind farm, it is fair to say such predictions have been proven right.
Under ideal wind conditions, the two 300kW turbines are able to supply up to 95 per cent of the outpost's power load. More typically, on a good month the station will on average derive up to 55 per cent of its power requirement from the wind generators. Figures for September 2009, for example, show the wind farm produced 142,172 kWh of power, which meant the station saved over 17,000 litres of diesel and avoided emitting 45 tonnes of carbon dioxide during that month alone.
Wind is the most obvious, but by no means the only force of nature that Antarctic bases have at their disposal for energy generation. On places like King George Island and Deception Island, there is potential to tap into geothermal resources.
Solar power can be surprisingly efficient in Antarctica, too. According to William Ray, the sustainable energy engineer with the British Antarctic Survey (BAS), there are areas in Antarctica that can receive more solar radiation over a six-month period than you would get anywhere in the UK over a full year.
"The Antarctic Peninsula, which is where Argentina, Chile and the British have a lot of their bases, is not as far south as people think: it's only 64° south," says Ray. "There, you tend to find that the atmosphere is very dry, so you don't get as much water vapour in the air. And water vapour tends to absorb solar radiation."
There are three other factors that help explain the high yield of solar panels in certain areas of the Antarctic Peninsula: a highly reflective, snow-covered ground surrounded by a vast ocean; predominantly clear skies; and extended summer daylight hours coinciding with the season when human activity is most intense.
The BAS has recently installed solar panels at three of its research stations: Rothera (located in Adelaide Island), Bird Island (South Georgia) and Signy (South Orkney Islands).
In the largest Rothera installation, 36 solar panels (each containing 16 evacuated tubes) are used to heat cold fresh air going into Bransfield House. In the two other stations, the vacuum tube solar panels are used to pre-heat hot water.
"They've been reasonably successful at achieving some savings," Ray says of the solar panels. "Unfortunately, it's not a perfect solution for Antarctica because you do lose the sun for quite a while."
In order to generate clean electricity, the BAS is considering the use of wind turbines at Rothera and Signy. But both potential deployments face considerable challenges.
"Unlike the bases of some other countries, our bases are located on sites where it's quite difficult to locate the turbines," says Ray. "You'd think that you've got a lot of space in Antarctica but you really don't - a lot of it is quite inaccessible. Rothera, for example, is on a very small peninsula on Adelaide Island and there's not a lot of land around there; it's very narrow and constricted.
"We've also got rocks and it's quite steep. On top of that, we've got an airstrip that runs right through the middle of the base, so we need to be clear of the aircraft in order to meet [aviation] regulations."
Another potential obstacle at Rothera is the presence of scientific instruments (particularly radar equipment), which nearby wind turbines could interfere with.
As for Signy, the fact that this was conceived as a biological research station tasked with studying local flora and fauna meant that the base was purposely situated in an area rich in bird colonies. "It's a very delicate balance to get the wind turbines in the right spot," Ray admits. "We want to do an environmental impact study there before we install any turbines."
One of the most ambitious green projects in Antarctica at the moment is that taking place on Ross Island. Home to New Zealand's Scott Base and the United State's McMurdo Station (by far the largest in Antarctica, capable of supporting more than 1,200 residents), this volcanic island is about to experience a sharp reduction in its heavy dependence on fossil fuels.
At Crater Hill, an elevated area sitting nearly halfway between the two bases, three new wind turbines will be erected by Christmas - effectively turning the spot into the world's southernmost wind farm.
Like in the Mawson installation, the machines have been supplied by Enercon, but they are slightly higher-spec models offering 330 kW each (990 kW in total).
The wind farm is being built by Meridian Energy (the largest state-owned electricity generator in New Zealand, which generates exclusively from renewable sources) in an alliance with Antarctica New Zealand, while the US National Science Foundation provides key logistics support.
Interestingly, the three turbines will supply power to both stations, whose 60Hz and 50Hz power grids were linked earlier this year in preparation for the imminent launch of the wind farm.
Once fully operational, some 460,000 litres of fuel (of the over four million litres that the combined stations currently use for power generation every year) are expected to be offset. This should reduce Ross Island's carbon footprint by 11 per cent, from 11,300 t/CO2 a year to just over 10,000 t/CO2.
"This is a proof-of-concept project to demonstrate that it's a good, reliable solution," says Scott Bennett, the Ross Island Wind Energy - Stage 1 project manager with Meridian Energy. "A successful outcome from this will lead into a larger development down there."
Investigations carried out by the company suggest that as much as 50 per cent of the combined energy requirements of the American and NZ bases could be met by an expanded (Stage 2) network of wind turbines located in either of two other potential sites on the island.
In the meantime, Stage 1 will be enough to switch off the diesel generators of the smaller, Scott base. "When the wind is blowing, we'll end up with Scott Base being fed from the wind farm itself, and the remainder of the energy going into McMurdo," Bennett says. "When it's not blowing, Scott Base will get its energy from the McMurdo diesel generators."
The particular challenges involved in designing and building a wind farm in Antarctica are manifold. Bennett says that, in their case, they have included a very tight work programme, logistics issues, project resources and the sheer freezing environment.
Starting with the design of the foundations of the turbines, the company had no choice but to resort to some inventive engineering.
"We had to move away from the traditional gravity pad type of wind turbine foundation due to the fact that you've got extremely low temperatures at Antarctica [so it's very difficult for concrete to cure], there's no batching plant down there, we haven't got the aggregates for the concrete and - one of the key drawbacks that a lot of people don't appreciate - all fresh water down there is made from sea water," Bennett explains.
A New Zealand company came up with a prefabricated, anchored structural steel foundation design that was entirely built in Christchurch and transported to Ross Island in 40ft containers on the annual supply ship.
"The ship arrives there pretty much towards the end of the season. So, if you're going to do any work in the current season, you need to have all the stuff shipped down there the previous season," says Bennett. "We've had to have everything planned and programmed down to the last nut and bolt. If you forget something, you've got no hardware shop down there…"
Belgians show how it's done
The closest any nation has got to producing a truly zero-emission scientific station in Antarctica is Belgium.
The brainchild of the International Polar Foundation's founding president Alain Hubert, the Princess Elisabeth Station has been designed from the outset to operate entirely on a combination of wind and solar power.
Like some of the British bases, thermal solar panels will be used to heat hot water. But the Belgian station will also incorporate 408 photovoltaic solar panels for power generation. Their total peak power output will be 50.6 kW.
The rest of the electricity will be generated by nine wind turbines (of which eight have already been installed; the ninth one was on its way to Antarctica at the time of writing) sitting atop the nearby Utsteinen mountain ridge. They will add another 54 kW of peak power.
The area on Dronning Maud Land where the station has been built is pounded by gusts of over 250km/h during the winter. At these sorts of speeds, most regular wind turbines would normally stop generating power in order to protect themselves. But the Belgian station's turbines, which were supplied by a Scottish company called Proven Energy, are 'reversed', meaning that their rotating structure is located behind (or downwind) the support mast.
"When faced with higher rotation speeds, the geometry of the turbine blades automatically collapses to reduce their aerodynamic efficiency," explains Johan Berte, project coordinator of the Princess Elisabeth Station. "This slows down the wind turbine without actually stopping it. So, even when you have very high wind speeds, the turbine will continue to produce energy."
Sustainable development was the driving force behind every aspect of the station's design. This includes everything from the materials used in the construction of the passive building to the intelligent central unit that ensures maximum efficiency in the use and conservation of energy and water.
The station's source of drinking water is snow, which is collected and melted by a device powered by solar thermal energy. "All water is treated, and approximately 70 per cent of the water in the water loop is recycled," says Berte.
Water treatment systems tend to be among the heaviest energy consumers at polar stations. The one at Princess Elisabeth has been designed for optimal use instead of for worst-case scenario (as is normally the case), which makes it much more energy-friendly.
Although the station was officially inaugurated in February 2009, there remain a few final components to install and process tests to be carried out during the current austral summer season.
Come February 2010, this will become the first Antarctic station to run almost entirely on renewable energy. Why almost? "The station has some backup generators installed for safety," says Berte. "This is a very hostile environment and we can't take too much risk."
If everything goes according to plan, the generators should only be on for a number of hours every year, mainly to check their functionality and for maintenance. Their consumption is expected to be in the order of a few hundred litres of diesel per year. In comparison, Berte estimates that a similar station running on pure fossil fuel would require 60,000 to 80,000 litres of diesel annually - just for heating and electricity.
"What you tend to find with those bases is that they're only occupied during the summer period, when it's sunny," says the BAS' William Ray. "It's much harder to think about a base that powers itself purely from renewable energy 365 days of the year. No one's really done that yet."
Asked about this point, Berte replies: "When we decided that the station was going to be a zero-emission building, it became very clear that, if you design a low-energy building, it becomes much easier to run it through the winter, too. This is especially true with the wind regime we have: we have excess energy during the winter, so we have a lot of dump loads because there's no way of getting rid of this energy."
Unlike conventional summer stations, the Belgian facility was designed for full-year occupation with 'close-down capability' during the winter. "When nobody is at the station and therefore the only energy consumption comes from the scientific equipment and satellite data transmission system, you're using a very limited amount of energy," Berte explains. "There're no bioreactors running, no kitchen use, etc, so the energy consumption is very low while your production is quite high. We can store some of that energy in the batteries, but once the batteries are full, they are full…"
The Princess Elisabeth programme is about to mark a new era of sustainable Antarctic research by demonstrating that a zero-emission station can stay 'open for business' for four months of the year. Could it one day raise the stakes again by doing it during the other eight? Watch this wind.