| With the rapid development of global economy,people' s requirement for energy is increasingly rise as well.Considering of the limit of regular energy reserves and pollutions caused by emissions,many countries have determined to develop and utilize solar resource as the most important clean energy to reach the sustainable development of national economy and the improvement of environment quality.The assessment can serve as significant preliminary work and basis for the utilization of solar energy resources. For the solar radiation observation stations are rare,which cannot meet the requirement of scientific research and engineering application,it will remain important to study the model of solar radiation and deduction of solar radiation capacity.At present,climatological equation for total solar radiation is a unitary linear regression equation based on total solar radiation and percentage of sunshine.Many academicians set up various equations for calculating the value of total solar radiation,making use of meteorological and geographical parameters including temperature,precipitation,relative humidity, cloudage,latitude and local altitude.The relative error between the calculated value based on the total solar radiation and percentage of sunshine and the measured value is lower and of higher accuracy,which can easily satisfy the application.However,it is a task deserving more research on to work out the model based on astronomical total radiation and percentage of sunshine,which can provide a calculated value with even lower relative error and higher accuracy.This paper develops the research on such issues in this senario.Firstly,this paper analyzes the climatological features of total solar radiation in Shandong Province.The results indicate that the change of total solar radiation in Jinan area shows an obvious downward trend with a range of 20.3MJ/m2.Before 1990,the total solar radiation in Fushan changed steadily while after then it has been keeping the level of 5000MJ/m2 for most of years.Although the values of total solar radiation in Juxian for the past years are higher than those in Jinan,the trends of change in both of the two regions are the same.According to the datas from three observation stations in Shandong,the monthly values of total solar radiation always reach the summit and the bottom in May and December respectively.It can be seen from the scatter diagram that there is an obvious positive correlation between total solar radiation rate and percentage of sunshine.Based on the datas of total solar radiation and percentage of sunshine from observation stations in Shangdong covering the period from the year when stations were built up to 2003,this paper sets up series of regression equations including unitary linear,quadratic polynomial,cubic polynomial, logarithmic,exponential,power exponential regression equations.Through analyzing multiple correlation coefficients of these equations,the regression equation for monthly total solar radiation with better fitted effect can be selected as the certain fitted equation of total solar radiation for the local area.The regression equations for monthly total solar radiation in Jinan,Fushan and Juxian are mainly cubic polynomial equations with only several exponential equations for specific months.The measured data of monthly total solar radiation in 2004 and 2005 for these three locations are chose for the analysis on relative error of fitted equations respectively. The results indicate that these fitted equations have a favorable fitted effect for the monthly total solar radiation in the local area.Except for some specific months with the relative error over 10%,the values for most of other months are all around 5%.In addition,these nonlinear equations have a better fitted effect than traditional linear equations,which show a better correspondence with the characteristics of the actual local total solar radiation.In use of those nonlinear equations,the characteristics of the change of monthly and annual total solar radiation in Shandong can be obtained,which can provide basis data for the distribution diagrams of monthly and annual total solar radiation.According to these diagrams,the values of total solar radiation in various regions of Shandong province are between 4542.61MJ/m2 and 5527.32MJ/m2.Among those values,Chengwu gets the minimum which is 4542.61MJ/m2 while Penglai gets the maximum with the value of 5527.32MJ/m2. There are big differences among the values of total solar radiation in various regions of Shandong.Compared to North Penglai and Longkou,total solar radiation in Jiaodong Penisula is lower,showing the characteristic of lower in South and higher in North in the province.Additionally,Kenli and Hekou in North Shandong have higher values of tatal solar radiation than the southwest and the east of Shandong.There is one point needed to pay more attention on.For the datas of total solar radiation in Juxian started to be kept from 1990,the datas of the past years before then are absent.This leads to a higher average annual total solar radiation with the value of 5300MJ/m2 in the region.Eventually,a higher result would be obtained by the regression equation of total solar radiation based on this higher value. The characteristics on distribution of solar energy resources and total solar radiation in Shandong are similar.The solar energy resources are relatively rich in North Jiaodong Penisula,the southeast and the north of Shandong. In those areas,the solar energy which can be used reaches or even exceeds 1400KW·h/(m2·a).The maximum capacity in Penglai region reaches 1536.59KW·h/(m2·a).By contrast,the solar energy resources in the middle, the west and the southwest of Shandong are relatively insufficient.The annual available capacity is less than 1400KW·h/(m2·a) in the Southwestern Shandong and with the minimum of 1262.85KW·h/(m2·a) in Chengwu.
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