Solar radiation measurements are not easily available, especially for the diffuse solar radiation. In this study, two models for estimating the diffuse solar radiation are proposed based on multiple predictors including the clearness index, relative sunshine duration, ambient temperature and...

Two models based on Li et al. (2011) are developed for general application in estimating the monthly average daily diffuse solar radiation in China. The validation of these models is performed by comparing with four existing empirical models against the measured data. It is found that the...

Eight models using only the sunshine duration for estimating the global solar radiation on a horizontal surface are evaluated at Changdu, Geer, Lasa and Naqu stations in Tibet, China against the measured meteorological data during 1994–2008. Based on statistical error tests, results show that...

The objective of this study is to demonstrate the feasibility of acquiring geothermal energy from existing abandoned oil and gas wells. The equations describing the heat exchange between fluid and rocks are developed, and parametric studies are conducted in order to specify the optimum values of...