دانلود رایگان مقاله انگلیسی انرژی خورشیدی در فلات تبت: تاثیرات جوی - الزویر 2018

ABSTRACT

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 3–6%, 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−2 , which is 85% of the corresponding annual irradiation at the TOA.

Conclusions

Four sites in Tibet were chosen for measurements of GHI. The measurements indicate a large solar energy potential on the Tibetan Plateau, with GHI values approaching 1300 W m−2 at summer noon under cloud-free sky condition, which are comparable with the values at TOA (1368 W m−2 ). A small portion of GHI values even exceeded the TOA GHI in situations with blue sky and with neighboring clouds that did not obstruct the line of sight. Tingri had the largest solar energy potential among the four study sites, and Nyingchi had the lowest. Lhasa had a larger solar energy potential than Nagchu. Within the time frame of a year, Lhasa was found to have a higher annual irradiation (7.6 GJ m−2 ) than Nagchu (6.8 GJ m−2 ). Spectral transmittances were estimated by use of a radiative transfer model (AccuRT). The atmosphere above the two sites in Tibet was much more transparent than above the two sites investigated in mainland China (Beijing and Chengdu), making the solar energy potential on the Tibetan Plateau promising for use of solar energy devices. The solar energy potential on the Tibetan Plateau is affected by cloud and aerosol, AccuRT was used to quantify the influence of each of these factors. The cloud and aerosol free sky annual irradiation was estimated to be reduced by aerosols by 3–6% for a typical range of AOD values in Tibet (0.17–0.27 at 588 nm). Clouds and aerosols were found to reduce the annual irradiation by 15% (1.3 GJ m−2 ) in Lhasa and 23% (2.0 GJ m−2 ) in Nagchu.