Solar energy radiation measurement with a low–power solar energy harvester

Abstract

Solar energy radiation measurements are essential in precision agriculture and forest monitoring and can be readily performed by attaching commercial pyranometers to autonomous sensor nodes. However this solution significantly increases power consumption up to tens of milliwatts and can cost hundreds of euros. Since many autonomous sensor nodes are supplied from photovoltaic (PV) panels which currents depend on solar irradiance, we propose to double PV panels as solar energy sensors. In this paper, the inherent operation of the low-power solar energy harvester of a sensor node is also used to measure the open circuit voltage and the current at the maximum power point (I MPP), which allows us to determine solar irradiance and compensate for its temperature drift. The power consumption and cost added to the original solar energy harvester are minimal. Experimental results show that the relation between the measured I MPP and solar irradiance is linear for radiation above 50 W/m 2 , and the relative uncertainty limit achieved for the slope is ±2.4% due the light spectra variation. The relative uncertainty limit of daily solar insolation is below ±3.6% and is hardly affected by the so called cosine error, i.e. the error caused by reflection and absorption of light in PV panel surface.

A Novel Distributed CDS Algorithm for Extending Lifetime of WSNs With Solar Energy Harvester Nodes for Smart Agriculture Applications

“…The network consists of temperature and soil moisture sensors placed in plant roots and a gateway. López-Lapeña and Pallas-Areny [45] developed a novel solar energy radiation measurement method with decreasing power consumption in WSNs having solar energy harvester nodes in agriculture. Zou et al [46] extended the lifetime of WSN with energy harvesting nodes using shadow detection.…”

Development of a Utility Model for the Measurement of Global Radiation in Photovoltaic Applications in the Internet of Things (IoT)

“…It is considered that the measurement of global solar irradiation incident on a flat surface through a pyranometer in the field of photovoltaic applications is the most reliable [29,30], since the desired physical magnitude is directly measured, and not estimated from other observations. Although it is important to note that the use of a pyranometer for the measurement of global solar radiation outside the field of research is not widespread, due to its high cost.…”

Heat Pipe Thermal Management Based on High-Rate Discharge and Pulse Cycle Tests for Lithium-Ion Batteries

“…Rising energy demands have led to a series of problems, such as increased fossil fuel consumption, depletion of non-renewable resources, environmental pollution problems, and political impacts [1][2][3]. Many scholars have studied clean energy, including wind [4,5], solar [6][7][8], geothermal [9,10], and tidal [11]. The use of batteries in electric vehicles (EVs) [12,13] to replace traditional fossil fuels can effectively reduce the global use of fossil fuels as automotive batteries provided good conversion and storage capabilities.…”