# Estimation of Direct Normal Irradiance at Antarctica for Concentrated Solar Technology
## 1 Introduction  
Since 1985, with the National Program of Research in Antarctica (PNRA) Italy has been engaged in missions in Antarctica; ENEA, the Italian National Agency for New Technologies, Energy and Sustainable Economic Development, is entrusted with the task of implementation and logistics, as well as organizational responsibility in the operational areas. Due to its geographical position, physical characteristics, distance from pollution sources and the almost total absence of anthropogenic disturbances, Antarctica is one of the most privileged places for the global observation of the planet. The climatic history of the last 10,000 years is recorded both in sediments and in continental ice. The answers and the causes of past climate change and variations in the sea level are the basis for understanding the causes of very short-term climatic variations and the influence of anthropogenic effects on the global environment. Italy (ENEA) maintains two permanent scientific bases in Antarctica: Mario Zucchelli Station (MZS, coordinates 74\({}^{\circ}\)41\({}^{\prime}\) S and 164\({}^{\circ}\)05\({}^{\prime}\) E) in the bay of Terra Nova overlooking the Ross Sea in the portion of the continent attributed to New Zealand and Concordia (DC, coordinates 75\({}^{\circ}\) S and 123\({}^{\circ}\) E) in the interior of the continent about 1200 km from MZS. MZS (Figure 1) is the reference point for all the Italian scientific activities in Antarctica. The management of meteo-climatological observations establishes one Italian activity conducted in Antarctica. The first installed automatic meteorological station was Eneide, at MZS. The purpose of Antarctic observations is to contribute to the monitoring of global climate change in an environment considered by the international scientific community to be very sensitive to changes in the climate. The Automatic Weather Station project (AWS) counts among several National Antarctic Programs in order to produce a vast observational network created specifically for the polar environment [2]. Today the Italian observation network includes 23 stations inside the AWS project [1] that have been positioned in the Antarctic territory during the different expeditions carried out so far. Sixteen of the AWSs are operational year round, while five are seasonal and dedicated to the flying activities near the scientific bases of MZS and DC, one is mounted on the survival modules of the crossbar of the International Trans Antarctic Scientific Expedition (ITASE) and another one is positioned on board the Italica oceanographic ship. The AWS are all based on VAISALA acquisition systems. The physical quantities sampled are generally temperature, humidity, pressure, wind speed and direction and in some stations global solar irradiance [1; 3]. All observational stations are calibrated regularly inside the AWS program conditions. In the austral summer months (September to February), when the permanent meteorological base Mario Zucchelli is mostly crowded with scientific staff, electrical demand grows. Unfortunately, in this privileged place for climatic and global warming studies, the scientific observatory still uses fossil fuels and low efficiency engines for heating and electricity demand that increase the carbon footprint in the atmosphere. In order to reduce carbon production in this protected area, we propose a renewable power plant that uses Concentrated Solar (CS) technology that could satisfy to some degree the electricity requirements in summer months. ENEA, since 2001, has been studying CS plants and has developed an innovative CS technology. Mentioned technology needs evaluation of solar radiation potential. To investigate the possibility and feasibility of the specific location for a possible CS plant, the application starts from the site characterization, not only in terms of basic meteorological parameters but also in the characterization of the solar radiation component, and specifically direct normal irradiation (DNI).