مقاله انگلیسی رایگان در مورد انرژی خورشیدی در فلات تبت – الزویر ۲۰۱۸

Solar energy utilization is expected to be increasingly important in order to meet future energy needs and limit CO2 emissions to the atmosphere. To quantify the solar energy potential on the Tibetan Plateau, we have analyzed global horizontal irradiance (GHI) measurements for a three-year period at four sites with different aerosol and cloud conditions. The measurements indicate a very large solar energy potential on the Tibetan Plateau, with a small portion of GHI values even exceeding the corresponding top-of-the-atmosphere (TOA) value. Compared to a hypothetical sky condition without aerosols and clouds all year, aerosols were found to reduce the annual irradiation by about 3–۶%, and the combined reduction by aerosols and clouds was found to be at most 23%. This reduction is very low compared to that at other sites around the world. For example, the west coast of Norway has a cloud/aerosol reduction effect of almost 50%, and Beijing has an estimated aerosol reduction effect of 35%. In Lhasa, Tibet the annual irradiation was found to be 7.6 GJ m−۲ , which is 85% of the corresponding annual irradiation at the TOA.

Introduction

In recent years, solar energy has played a major role in the global energy transformation trend. Solar photovoltaic (PV) system has become one of the top three electricity sources in Europe. Since 2011, the global total installed solar PV capacity has increased more than three times from 69 GW to 229.3 GW by the end of 2015. In 229.3 GW, China shares 43.3 GW, which is 18.9% of total installed capacity. Germany occupies 39.6 GW (17.3%) and Japan takes 34.3 GW (15.0%). China now is leading global PV market with largest share of total installed capacity (Europe, 2016). In a recent study of hourly solar irradiance in the period from 2001 to 2010 of about 200 sites in China, Tibet was found to have the highest annual PV capacity factor, which indicates highest annual solar power resources. The next provinces were Yunnan, Hainan, West Inner Mongolia, Gansu and Ningxia (He and Kammen, 2016). The PV industry requires realistic statistics of solar resource during the development period (plant location) and also anticipation for possible variations of this resource during exploitation stage (energy storage). The most common parameter used to express solar resource is the global horizontal irradiance (GHI) [W m−۲ ], which is the total amount of solar energy falling on a horizontal surface per unit area per unit time integrated over the solar spectrum. The GHI is the sum of the direct normal irradiance (DNI) and the diffuse horizontal irradiance (DIF). In spite of the importance of solar statistics, ground-based solar irradiance observation sites are not widely spread around the world. Most solar irradiance data are based on satellite-observations combined with modeling and have large spatial coverage. Such estimates need to be complemented with accurate ground measurements to improve their local accuracy, since satellite algorithms do not take into account local effects due to e.g. high mountains, desert, and snow (Suri and Cebecauer, 2014; Cebecauer and Suri, 2016; Polo et al., 2016). China has 130 observation sites for measuring the solar irradiance, but this number is only 6% of the number of widely distributed meteorological stations (Chen et al., 2014; CMA, 2017). In the US and globally, only 1% and 0.2%, respectively, of the meteorological stations have solar energy observations (Thornton and Running, 1999; Wilcox, 2012). According to information from Bureau of Meteorology (BOM, 2017) (last updated 16 Nov 2017), Australia has one-minute solar irradiance measurements at 21 stations, but only 9 of these stations are running long-term with data available at World Radiation Data Centre (WRDC) (WRDC, 2016). The main reason of this shortage of solar irradiance measurements is due to the high cost associated with operation and maintenance of ground-based instruments (Sengupta et al., 2017).