Long-Range Distributed Solar Irradiance Sensing Using Optical Fibers

Abstract

Until recently, the amount of solar irradiance reaching the Earth surface was considered to be a steady value over the years. However, there is increasing observational evidence showing that this quantity undergoes substantial variations over time, which need to be addressed in different scenarios ranging from climate change to solar energy applications. With the growing interest in developing solar energy technology with enhanced efficiency and optimized management, the monitoring of solar irradiance at the ground level is now considered to be a fundamental input in the pursuit of that goal. Here, we propose the first fiber-based distributed sensor able of monitoring ground solar irradiance in real time, with meter scale spatial resolutions over distances of several tens of kilometers (up to 100 km). The technique is based on an optical fiber reflectometry technique (CP-ϕOTDR), which enables real time and long-range high-sensitivity bolometric measurements of solar radiance with a single optical fiber cable and a single interrogator unit. The method is explained and analyzed theoretically. A validation of the method is proposed using a solar simulator irradiating standard optical fibers, where we demonstrate the ability to detect and quantify solar irradiance with less than a 0.1 W/m2 resolution.

Reaching Long-Term Stability in CP-ϕOTDR

“…MHz was observed at the end of the 30-days measurement, which corresponds to a total temperature error of ~3 mK (standard deviation across all fiber positions). Given the 1-2 higher orders of magnitude in deviations reported in the literature over daily CP-φOTDR temperature measurements (~20 mK standard deviations after a period of 24 h) [26], these results demonstrate that we were able to minimize those errors and achieve an unpreceded long-term stability in CP-φOTDR systems, and DAS in general.…”

A complex wireless sensors model (CWSM) for real time monitoring of dam temperature

“…The sun radiations are absorbed by the sensor and sensor produces the readable electric signals. The fabrication of sensor can be seen in following references [ [50] , [51] , [52] ].

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Advances in phase-sensitive optical time-domain reflectometry

“…With appropriate optical configurations, Φ-OTDR is capable of measuring vibration 23 , strain or temperature distribution 36,37,175 at high spatial resolution (~m) over long distance (~km). Such ability makes Φ-OTDR a promising tool in various scenarios, including geological exploration , perimeter monitoring [102][103][104][105][106][107][108][109][110][111][112] , traffic sensing 73,[113][114][115][116][117][118] , partial discharge monitoring 78,[119][120][121] , and other novel applications 94,95,[176][177][178][179][180][181][182][183] . This section reviews the recent progress of advancing Φ-OTDR applications in separate fields.…”

“…By translating the solar irradiance to temperature change of the sensing fiber, distributed solar irradiance sensing system was proposed based on chirped-pulse Φ-OTDR 179,183 . One black-painted fiber with high solar irradiance absorption rate was adopted as the sensing fiber, while another standard fiber with low absorption rate was used as reference, as shown in Fig.…”