June, 2013 Assessment of green power production in Antarctica Christoffer Hallgren (christoff[email protected]) Abstract Traditionally, fossil fuels have been the energy source to power research stations in Antarctica. With increasing awareness of climate change and local environmental effects associated with use of fossil fuels, the demand for replacement green energy power supply have increased rapidly. In this article, the potential for wind and solar power in Antarctica is assessed. The study is based on 34 years of reanalysis data from the Modern-Era Retrospective Analysis for Research and Applications (MERRA) focusing on the location for the experiment ARIANNA (Antarctic Ross Ice-Shelf Antenna Neutrino Array). Results are compared with the stations Mawson and Princess Elisabeth, where wind and solar power already is operational, and with the Amundsen-Scott station. The average wind speed for the ARIANNA site is around 7:5 m=s during winter and 6:0 m=s during summer. Comparing with Princess Elisabeth, the average wind speed is approximately 5 m=s lower. The generally low wind speeds at the ARIANNA site suggest that wind turbines with a low cut-in speed should be used. The strong influence from katabatic winds make wind direction persistent, which is preferable. The potential for solar power production at ARIANNA is expected to be 10% lower comparing with Princess Elisabeth. Keywords: ARIANNA, MERRA, Antarctica, wind power, wind energy, solar energy, katabatic winds 1. Introduction Protocol on Environmental Protection came into force. The restrictions were created with the aim The Antarctic continent, with its remoteness and to safeguard the unique Antarctic biosphere and po- extreme environmental conditions, is ideal for many lar environment (Secretariat of the Antarctic Treaty scientific experiments. As the possibilities to colo- 2013). nize the continent and construct very large experi- During the 1960s, a nuclear power plant supplied mental setups have increased, the question of how the McMurdo station, maintained by the United to supply the research stations with electrical power States, with energy. Due to spill of nuclear waste has become a hot topic. and the public opposition, it only lasted for ten Traditionally, fossil fuels, have been used as the years, and nuclear energy is nowadays prohibited primary energy source in Antarctica. During the by the Antarctic Treaty System (Reid 2005). last decade, the knowledge and general awareness Replacing fossil fuels with wind turbines might about the environmental impact from fossil fuels be the first thing that comes to mind. For exam- has increased rapidly. Thus, the need for green en- ple, the two 300 kW wind turbines deployed at the ergy sources is a burning issue. Australian Mawson station account for 95% of the The original Antarctic Treaty, dating from 1959, energy for electricity, heating and fresh water pro- was formulated to protect the continent from mil- duction. Any excess of energy can be used to gener- itary conflicts and ensure that it would solely be ate hydrogen from water and stored in fuel cells, to used for peaceful and scientific purposes. In 1982, be used when the wind drops (Australian Antarctic the agreement of Conservation of Antarctic Flora Division 2013). and Fauna was added to the treaty and in 1998 the Despite the many benefits of wind turbines, there 1 are several aspects to consider before construction In this article, the wind power potential is re- can begin. Any anthropogenic disturbance affects viewed from a meteorological perspective, describ- the image of Antarctica as an untouched desert. ing the general wind situation and using 34 years Since the landscape generally is open, wind tur- of reanalysis data to compare the wind resource at bines will stand out and be visible from great dis- different research stations in Antarctica in practice. tances. During installation, there is a large impact Extra attention is paid to an area centered on the on the local environment as explosives are used to Ross shelf, the location for the ARIANNA exper- prepare the ground. When wind turbines are run- iment (Antarctic Ross Ice-Shelf Antenna Neutrino ning, wildlife is affected as e.g. the Weddell seals Array). are sensitive to low frequent sounds (Ray & deCamp In addition to this, the preconditions for solar 1969) and birds may accidentally get hit by the ro- power are discussed briefly. tor blades. The remarkable Antarctic climate causes prob- 2. Antarctic wind climate lems unseen elsewhere. Tin et al. (2010) report that wind gusts often exceed 70 m/s at the Mawson sta- For most places on Earth the weather and prevailing tion and that the low temperatures are a problem winds are determined by the movements of synop- when constructing the foundations. Due to snow tic systems. However, Antarctica with its unique accumulation the wind turbines have to be lifted characteristics has a quite special wind pattern. approximately one meter every year. On the other Since there is no heating from incoming solar ra- hand, advantages are the persistent strong winds diation during the Antarctic winter, the surface is and the dry Antarctic atmosphere which eliminates cooled by emitted long wave radiation. The sur- the need of a de-icing system for the turbines (Tin face in turn cools the adjacent air. The cooler air et al. 2010). is heavier and therefore strives to sink, following Other possible renewable energy sources are solar the slope of the terrain downwards. These gravity katabatic winds power, geothermal power and water power. winds are called and are described in more detail in an article by Parish & Cassano Solar power can be used in two ways, either for (2003). direct heating, or by using photovoltaics to convert The katabatic winds converge in narrow valleys the energy to electricity. Both alternatives cause and are channeled towards the coast. This results minimal impact on nature as they can be mounted in a constant wind direction and, as a matter of on existing buildings. However, the drawback is fact, the surface winds in Antarctica are among the that there is no sunlight during the winter months. most persistent on Earth (Parish & Cassano 2003). If the temperature gradient in the ground is During summer, insolation counteracts the cool- large enough, geothermal power is a possible en- ing of the surface, thereby decreasing the strength ergy source. It is available all year round, but the of the katabatic winds. installation has a large impact on the local environ- The Antarctic coastal zone is one of the most ac- ment. Water power in the shape of currents, waves tive cyclogenetic regions on Earth. Thus, in this and tidal elevation are possible energy sources for area surface winds are affected by the wind field as- the coastal stations in the future, when the tech- sociated with the generation of intense low pressure nologies are improved (McKenzie et al. 2010). systems (Parish & Cassano 2003). Besides installing green energy turbines, one of the most effective ways of creating a more environ- 3. The MERRA data set mentally friendly research station is by education of the staff and encouraging a change of attitudes. For To be able to study the Antarctic wind resource example, many australian staff members changed and compare the wind power potential at several their behaviour when informed that the cost of en- scientific stations, reanalysis data from the Modern- ergy in Antarctica is at least five times higher than Era Retrospective Analysis for Research and Ap- the cost to a suburban consumer in Australia (Tin plications (MERRA) (Rienecker et al. 2011) has et al. 2010). been used for the calculations. The data set is pro- Belgium’s Princess Elisabeth station, opened in vided by National Aeronautics and Space Admin- 2009, is in the front line when it comes to using istration (NASA) and covers the modern era, from renewable energy sources. The goal is to run com- 1979 and onwards, during which remote sensing has pletely on green energy with diesel generators as an been dominant when collecting data about the at- emergency backup. Nine 6 kW wind turbines are mosphere. producing 90 MWh each year and 300 m2 of so- The reanalysis data is created by combining dif- lar panels contribute with 50 MWh. On the roof ferent types of measurements (such as surface ob- tops, 24 m2 of thermal solar panels are installed, servations, radio soundings and satellite data) and providing heat for the interior and melting snow for using a numerical model to calculate a gridded data drinking water (Tin et al. 2010). set in a consistent way. 2 Table 1: Summary of the MERRA data that has been used in the calculations. Data product Resolution Averaging Variables Used for IAU 2d atmospheric Native Monthly u; v at 2, 10 and 50 m Antarctic continent single-level diagnostics IAU 2d atmospheric Comparison of Native 1h u; v and T at 10 m, ps single-level diagnostics resarch stations IAU 2d atmospheric u; v at 2, 10 and 50 m, Native 1h ARIANNA area single-level diagnostics T at 10 m, ps IAU 2d surface and Surface incident ARIANNA, top of atmosphere Native 1h shortwave flux Princess Elisabeth radiation fluxes Princess Elisabeth station Table 2: Coordinates for the grid points closest to the research stations studied. Mawson station Station Used grid point ARIANNA 78.5 °S 165.3 °E Amundsen-Scott 90.0 °S 0.0 °E Amundsen-Scott 1 station Mawson 68.0 °S 62.7 °E Princess Elisabeth 71.5 °S 23.3 °E 1 The chosen grid point is positioned south of the Mawson ARIANNA site station, to make sure that it is not located over sea. for the ARIANNA experiment, located on the Ross Figure 1: Map with approximate height contours Shelf approximately 100 km south of the McMurdo showing the location of the four research stations.