Site analysis in the Argentinean Andean region for the placement of astrophysical observatories and solar photovoltaic power plants: The case of the “Leoncito 2” site

Abstract

After a detailed search for possible sites where to place astrophysical facilities in Argentinean Andean region, a location labeled as LEO 2 (31°24′22″ S, 69°29′32″ W, 1630 masl) is proposed. It is placed near the largest Astronomical Observatory of Argentina: Complejo AStronómico El LEOncito (CASLEO). Its advantages are: a good altitude to detect the maximum development of cosmic ray showers, high spectral transmittance to UV and visible ranges, very low aerosol content (mean particle concentration measured at ground with an optical particle counter PM2.5 = 1.52 µg m−3 and PM>2.5 = 6.83 µg m−3, mean Aerosol Optical Depth at 550 nm = 0.027 (measured from space using the SeaWiFS instrument on board of the SeaStar NASA satellite). A local meteorological analysis was done, using data measured in situ, which shows a typical desertic site with the following mean annual (std. dev.) values:mean annual temperature 18.93 (7.66) °C, mean annual relative humidity 28.76 (20.55)%, low/ moderate mean annual average wind speed 11.63 (8.78) km/h, low mean water content (0.73 cm) and rather low mean cloud coverage fraction (cloud coverage fraction): 0.29 (0.02) (for the period 2003–2016 from Aqua/NASA satellite MODIS device) and 0.25 (0.01) (for the period 2000–2016, Terra/NASA satellite MODIS device). Concerning the conditions for the placement of photovoltaic solar power plants, some positive aspects that can be remarked are a large rather flat available surface (336 km2) with very good levels of annual mean horizontal solar irradiation: Global (2334 kWh m−2 per year), Direct (3127 kWh m−2 per year) and Diffuse (394 kWh m−2 per year). Optimum angle to place solar panels at this site is determined and the global tilted solar irradiation is calculated (2689 kWh m−2 per year). In comparison with an African (Ouarzazate, Morocco) and Asian (Dubai) sites, the analysed site present better annual irradiation levels being the Global horizontal irradiation at the Argentinean site 8.1% and 10.3% higher than those calculated for the African and Asian site respectively. Also, a comparison is made of different solar cells (monocrystalline Si, polycrystalline Si and perovskite), through the calculation of the generated photocurrent (mean produced solar photovoltaic current per unit cell surface), considering the atmospheric and solar radiation parameters found for the studied site. We thus conclude that the proposed site in the Andes range is well suited for the placement of Astrophysical facilities, as well as Photovoltaic solar power plants.