Solar Photovoltaic Power: Short Term Volatility and Its Future Under Climate Change

Abstract

Solar power is becoming increasingly important as a source of energy in the United States. While solar represents a low-emission source of energy, integrating it into the electrical grid is challenging. The power output of solar is not controlled by operators, but is instead determined by the weather. Since solar power is not able to be controlled as a typical power station would be, analyzing its behavior is essential. This paper looks at three main points: the significance of short term variability in solar power output, mitigation techniques for short term variability, and how solar resources could change over the 21st century. New England is the geographical focus of the analysis of short term variability as well as the geographical focus of the mitigation analysis. This region was chosen because its climate makes it especially susceptible to short term variability. Additionally, its solar industry is already being affected by policy decisions where short term variability plays a role. This study found that short term variability of solar photovoltaic arrays was significant in both magnitude and frequency. Over the course of a year, panels could be expected to fluctuate over 95% of their rated power output in a 5 minute time interval. Additionally, a strong seasonal correlation was found with short term variability. Variability reached a minimum in the winter, while peaking in the late spring and early autumn. The mitigation analysis found that the addition of a storage system could effectively moderate the effects of short term variability produced by solar panels. The driving factor of the effectiveness of the storage system in mitigating variability was its maximum power output. The Southwestern United States is the focus for the analysis on how solar resources may change in the 21st century. This region was chosen because it currently has the best solar resources in the US, which may lead to expensive and long-lasting infrastructure being installed in the area. Thus, the projected climate of the region becomes important. This study finds that solar resources in the Southwestern United States are projected to remain relatively steady over the coming century. The quality of the solar resources in the Southwest is expected to be maintained even under a medium or high carbon dioxide emissions scenario. Interestingly, the average cloudiness of the region is expected to increase with no effect on the amount of solar radiation the region receives.