The rising demand for sustainable energy requires to identify the sites for photovoltaic systems with the best performance. This paper tackles the question of feasibility of photovoltaic power plants at high altitude. A direct comparison between an alpine and an urban area site is conducted in the south of Austria. Two low-cost automatic photovoltaic power measurement devices with dual-axis sun tracking and maximum power point tracking are deployed at two test sites. The system periodically performs a scan over the southern semihemisphere and executes maximum power point adjustment in order to assess the performance for a given direction. The gathered data shows a higher photovoltaic power yield in the higher altitude test site. Furthermore, the high altitude photovoltaic power as a function of azimuth and elevation angle appears to be not only higher but also more flat than in lower altitudes. This indicates a lower power loss in case of deviation from the optimal solar angles. The results show that even on low-cost hardware a difference in photovoltaic power can be observed, even though in this experiment it amounts to less than 5% increase of peak power in higher altitudes. However, the measured peak powers on the mountain are more stable and therefore closer to a constant level than the heavily fluctuating peak power values at the low altitude site. Additionally, a slight shift in optimal elevation angles between altitudes can be observed, as the optimum angle turns out to be lower on the high altitude site. This angle shift could be caused by snow reflections on the mountainous test site.

中文翻译：

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使用移动双轴跟踪系统比较高山地区的太阳能功率

对可持续能源的需求不断增长，需要确定性能最佳的光伏系统用地。本文解决了高海拔地区光伏电站的可行性问题。在奥地利南部，对高山和市区进行了直接比较。两个测试地点部署了两个具有双轴太阳跟踪和最大功率点跟踪功能的低成本自动光伏功率测量设备。该系统定期在南半球进行扫描，并执行最大功率点调整，以评估给定方向的性能。收集的数据显示，在较高海拔的测试地点，光伏发电量更高。此外，与低海拔高度相比，高海拔光伏发电作为方位角和仰角的函数似乎不仅更高而且更平坦。这表明在偏离最佳太阳角度的情况下，功率损耗较低。结果表明，即使在低成本硬件上，也可以观察到光伏功率的差异，即使在此实验中，光伏功率的差异在较高海拔下的峰值功率增加不到5％。但是，与低海拔站点上剧烈波动的峰值功率值相比，山上测得的峰值功率更稳定，因此更接近恒定水平。另外，可以观察到海拔之间的最佳仰角略有偏移，因为最佳角度在高海拔地点变小了。