Pyranometer Sensor Research Articles

Multivariate Imputation Chained Equation on Solar Radiation in Automatic Weather Station

Solar radiation is one of the crucial weather observation variables Its variable has a role in renewable energy solutions, agriculture, meteorology, and hydrology. AWS is one of instrument that use to observing weather especially solar radiation. AWS has a pyranometer sensor used to measure solar radiation. Unfortunately, the instrument has problem like the igh cost of supplying, installing, maintaining, and calibrating the equipment. Due to this, there is a lot of empty data, and the actual data cannot be properly measured. Imputation of solar radiation data using MICE algorithm can be solution. This study using BLR, NRR and RFR estimator to estimating solar radiation data. AWS Staklim Banten as target and other AWS as input. The period from January 1, 2018 - February 12, 2024. The performance evaluation of the solar radiation imputation estimator is still according to WMO operational requirements for solar radiation measurements, which can be seen from the resulting MAPE value < 8%.

Determining the Irrigation Performance of Solar Panels Operating with a Sun Tracking System

In the study, utilizing the relationship established between plant water consumption and solar radiation, an irrigation system was attempted to be automated through a Programmable Logic Control (PLC) controlled program for tomato plants grown in an open field. The system has obtained its required energy through solar panels, utilizing solar energy as its power source. The performance of the system has been attempted to be evaluated through the yield and quality parameters of the cultivated plants by yield, mean fruit weight and width, titratable acidity, total solids, pH, leaves (fresh+dry) weights, stem (fresh+dry) weights, leaf area, plant height. The PV panels used in the system were equipped with a solar tracking system to pump more water at a lower cost. This has led to an increase in the efficiency of the panels.
 The solar radiation values obtained with a pyranometer sensor during irrigation were processed through the software written in the PLC's memory. The amount of water consumed by the plant the next day was calculated, and it was attempted to be automatically supplied to the plant's root zone at 10:00 am. The system has been made continuous by being controlled with automation and SCADA. The development of the plants, temperature, humidity, and radiation levels were measured, and the system's irrigation performance was determined according to the moisture level change in the soil.

Importance of solar radiation and the need for improved respect to Sun by Agrometeorologists

Solar radiation refers to energy produced by the Sun, some of which reaches the Earth. This is the primary energy source for most processes in the atmosphere, hydrosphere, and biosphere. Solar radiation is of crucial importance inproviding the energy source for photosynthesis. During 1973 to 1977, when I did my Ph.D. in Agroclimatology in the Iowa State University, USA, I conducted the field experiments during 1975 and 1976 on soil-plant-water relations, growth and nutrient uptake patterns of field grown soybeans under water stress at the Western Iowa Experimental Farm, Castana. During these experiments, the solar radiation was measured with a pyranometer sensor mounted on an anodized aluminimum base. Daily solar radiation values were obtained from an LI-500 integrator attached to the pyranometer sensor. The attenuation of photosynthetically active radiation (PAR) and net radiation (NRAD) in the soybean canopy was determined during the growing season by using vertical profiles of radiation and leaf-area-index values. Once I received my Ph.D., I worked at the Headquarters of the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in Hyderabad from 1977 to 1983 and at the ICRISAT Sahelian Center, Niamey, Niger from 1984 to 1996. In several field experiments in ICRISAT, the hourly values of net radiation were obtained through net radiometers mounted above the crop canopies. The growth and interception of PAR in a maize/pigeonpea intercrop and sole maize and sole pigeonpea crops grown in large plots were compared. The productivity of maize, sorghum, pigeonpea and a maize/pigeonpea intercrop in the operational research watersheds was measured in relation to the interception of PAR. In another study, it was shown that different shading ability of the crop canopies was one of the factors which determined the crop/weed competition balance and thus contributed to differential crop productivity observed in different cropping systems. Afterwards, when I worked at the World Meteorological Organization from 1996 to 2016 as the Chief of the Agricultural Meteorology Department, as the Director of the Climate Prediction and Adaptation Branch and as the Acting Secretary of the Intergovernmental Panel on Climate Change, a lot of work was done on Solar Radiation. Given all the above work on Solar Radiation, I emphasized the need for improved respect to Sun Bhagawan by Agrometeorologists at the end of this article.

Study of vertical solar irradiance and local scale climate to assess passive cooling potential in Tangerang of Indonesia

Solar radiation information is very important in green building design, namely for the daylighting, solar heat gain prevention as well for solar energy utilization. This study uses solar radiation data from six pyranometer sensors for measuring the horizontal component (global horizontal irradiance (GHI) and infrared irradiance) and the vertical component (pyranometer sensors to the north, south, east, and west) located in Tangerang, Indonesia. Measurements have been filtered for one year from January 2021 to December 2021. The solar radiation observation is complemented with other measurement of climate elements, such as wind speed and direction, dew point temperature, relative humidity, and air temperature. The diurnal and seasonal patterns of solar irradiance and other climatic elements have been observed using the visualization technique of heat maps. The results show that sensors pointing north experience an increase in solar intensity in May, June, July, and August. Meanwhile, sensors that point to the south experience the increases in solar intensity in November, December, January, and February. The increase in radiation intensity towards the east occurs from 07.00 to 10.00 local time (LT), while the increase in sensor intensity towards the west occurs from 14.00 to 16.00 LT. The results of solar radiation analysis in horizontal and vertical surfaces are combined with other climate elements to create a bio-climatic design guideline suitable for buildings in the hot and humid climate.

Analysis of global solar energy dynamics on horizontal module in Minna, Niger state, Nigeria

The availability of solar energy in any location on the earth surface is affected by time of the day and seasonal variations, and in some instances loads vary in accordance with seasons also. Therefore, accurate knowledge of the quantity available at any particular location and time and the dynamics is imperative for solar power system design and installation. In this study, analysis of global solar irradiance on horizontal surface was carried out with the consideration of the prevailing atmospheric conditions and seasons in Minna, Nigeria. Li-200SA MA200 pyranometer sensor, incorporated with CR1000 software-based data logging system with computer interface, placed horizontally at the same test plane and at about three meters of height were employed to measure global solar irradiance. The logger was programmed to measure and log solar irradiance at every 5 minutes intervals from 8:00 am to 7:00 pm local time for the duration of 3 years from 2016 to 2018. Data analysis was carried out to obtain the hourly, daily, monthly and yearly global irradiance dynamics on horizontal surface using Excel spread sheet. The result shows seasonal variations.

A Conversion Efficiency Determination of High Efficiency Solar Cells with the Parabolic Dish Concentrating System

Aims: Field test for the conversion efficiency determination of high concentrating solar cells with the parabolic dish concentrating system in a tropical location. Background: Typical solar cell system using in a tropical location is a fixed panel via commercial grade mono crystalline, poly crystalline or amorphous solar panels. They have low conversion efficiency, so they need a wide area to enhance electrical energy. The consequence is low yielding in terms of economics and unpopular use in an urban zone. Objective: To test for the conversion efficiency determination of high concentrating solar cells with the parabolic dish concentrating system in a tropical location. Methods: The research was conducted at the top of Nakhon Ratchasima Rajabhat University (NRRU) Science Center Building, Nakhon Ratchasima, Thailand. The four multi junction solar cells were connected together to receive the reflecting concentrated sunlight from the parabolic dish. The conversion efficiency of the 160 watts peak mono crystalline solar cell panel for a comparing purpose was also determined. Multi junction solar cells with parabolic dish concentrating and cooling systems, solar cell panel, pyrheliometer, pyranometer and light sensor were set up on the dual axes sun tracker. Data were gathered every 5 minutes all day from January 2018 to February 2019 for all 3 seasons via the automatic data logging system. Results: The results had presented that the average conversion efficiency of high concentrating solar cell module with the parabolic dish concentrating system for 100x and of the 160 watts peak mono crystalline solar cell panel was 15.18% and 9.46% respectively, with the percentage difference of 56.45%. While the average output powers per unit area per year of multi junction solar cells with concentrating system and mono crystalline solar cell panel were 98,544.92watt/m2 and 664.37watt/m2 respectively, with the ratio of 148.33. Conclusion: It is clearly seen that, in terms of conversion efficiency and output power per unit area per year, the multi junction solar cells with the parabolic dish concentrating system have more advantage than the typical mono crystalline solar cell panel. Other: Other: Especially from the economical aspect, the utilization of the parabolic dish concentrating system with MJ solar cells can reduce the land investment cost and also encourage solar cell utilization not only in rural but also in urban for the tropical climate countries.

Microclimate Condition in the Natural Ventilated Greenhouse

A Greenhouse has a different microclimate compared to the outside field. Climate parameters such as solar radiation and air temperature are important parameters that affect plant growth and productivity. This research aims to understand the relation of climate factors in the inside and outside Greenhouse, the effect of microclimate on evapotranspiration and to predict the amount og evapotranspiration inside the Greenhouse. Microclimate analysis was held in two stages, the firststage was from February 5 to March 21, 2018 and the second stage from March 19 to April 29, 2019 at the Department of Civil and Environmental Engineering, IPB University. Primary data was measured by the Decagon sensor. Solar radiation was collected using the Decagon PYR Pyranometer sensor and air temperature using the Decagon VP-4 sensor. Based on the result, the daily air temperature inside the Greenhouse was higher than that of the outside. The inside solar radiation was lower than that of outside the Greenhouse. The relative humidity fluctuated, and the air pressure was higher inside the Greenhouse. Evapotranspiration inside the Greenhouse was lower than outside and solar radiation was the most determining factor of evapotranspiration.

Using Artificial Intelligence on environmental data from Internet of Things for estimating solar radiation: Comprehensive analysis

Solar radiation measurements are highly important for achieving energy efficiency in smart buildings as well as solar energy production. They are commonly acquired with pyranometer sensor device. However, due to its high initial and maintenance costs it is not densely deployed in the field. Consequently, it provides only limited coverage as a data source for solar radiation. Hence, theoretical, empirical and/or data-driven models are utilized to estimate solar radiation in areas without pyranometers using only data from meteorological sensor stations, which on the other hand are widely available and obtained from sustainable sensor networks. In this paper, end to end process is described for building hybrid models for solar radiation using Artificial Intelligence (AI), or more specifically Machine Learning (ML) methods, after which a detailed analysis is performed on (1) the accuracy of the models regards to their parameters and input features, (2) the sustainability of the models in the real world, and finally (3) their feasibility in (near) real-time monitoring.The results are expressed with relative root mean squared error (RRMSE) and they show that hybrid models outperform model- and data-driven ones, with artificial neural network giving the best results (RRMSE = 0.0393). Additionally, the models can be enhanced by performing an informed feature selection, where a posteriori selection proves to be better than a priori selection (RRMSE = 0.0371). Further investigation shows that randomly selected input data gives faster model convergence as expected. However, sequential input data can match it if model training starts with autumn or spring data when weather exhibits sufficient variety. When applied on different times scales, all models perform best on 3h scale rather than daily, where random forest (RRMSE = 0.0275) outperforms neural network (RRMSE = 0.0315). However, for (near) real time usage the models perform almost the same as for daily, with RRMSE of 0.0469 for 1min scale with neural network. This demonstrates the feasibility of the hybrid models in Internet of Things (IoT) applications, which commonly require at least hourly intervals for solar radiation.

Smart Energy Meter and Data Logger

The paper is aimed at discussing the coming technological trends in smart energy monitoring and tracking and to suggest any possible improvements in the same. The paper showcases an economical Rasberry Pi based model for smart energy metering and automatic data logging. The system under study uses a PQ analyzer for data monitoring, DHT22, pyranometer sensors for data acquisition. The various communication protocols for data transfer like Modbus, I2C, RS485 are studied with regard to the system. The sample size of data is from a 5kW, 302.2 V solar panel system. A three-phase solar inverter provides the electrical power output. A Meco solar analyzer present at University lab has been used to log electrical data. A major drawback of the same is its inability to measure data while the panels are connected to a load. Thus, a smart energy meter that constantly monitors electrical data as well as ambient environmental conditions has been implemented with the help of raspberry pi. Data such as irradiance, temperature, voltage and current are taken. Data is automatically logged into a SQL database. The aim of this paper is to study the current technological trends and propose possible areas of improvement in the current technology.

A Green Energy Application in Energy Management Systems by an Artificial Intelligence-Based Solar Radiation Forecasting Model

The photovoltaic (PV) systems generate green energy from the sunlight without any pollution or noise. The PV systems are simple, convenient to install, and seldom malfunction. Unfortunately, the energy generated by PV systems depends on climatic conditions, location, and system design. The solar radiation forecasting is important to the smooth operation of PV systems. However, solar radiation detected by a pyranometer sensor is strongly nonlinear and highly unstable. The PV energy generation makes a considerable contribution to the smart grids via a large number of relatively small PV systems. In this paper, a high-precision deep convolutional neural network model (SolarNet) is proposed to facilitate the solar radiation forecasting. The proposed model is verified by experiments. The experimental results demonstrate that SolarNet outperforms other benchmark models in forecasting accuracy as well as in predicting complex time series with a high degree of volatility and irregularity.

Evaluation of Clearness and Diffuse Index at a Semi-Arid Station (Anantapur) using Estimated Global and Diffuse Solar Radiation

In the present study, collocated and simultaneous measurements on meteorological parameters and solar radiation on horizontal surface were obtained from different meteorological sensors and pyranometer sensor over a semi-arid station, Anantapur (14.62° N, 77.65° E and 331 m asl) during January–December 2013. The temperature is usually lower at midnight, decreasing in the early hours of the morning around 08:00 LT (Local Time) (24.71 ± 2.7 °C), and then increasing rapidly until just after midday at 15:00 LT (31.88 ± 3.2 °C). It decreases to 26.70 ± 2.9 °C during the night around 23:00 LT. The relative humidity ranges from 30–76%, 20–65%, 46–80% and 48–90% during winter, summer, monsoon, and post-monsoon seasons respectively. The diurnal variation of soil moisture exhibits slight variations at different depths over the region. The diurnal and monthly variations of solar radiation as well as clearness index (k t ), diffusion index (k d ) were studied in the present study. In diurnal variation, it shows a steady rise in solar radiation received at the surface after 7:30 LT and attains a maximum solar radiation between 12:00 – 13:00 LT. The amount of solar radiation also varies depending on the time of day and the season. The annual mean of daily global, extraterrestrial and diffuse radiation at Anantapur is found to be 202.43 ± 40.45, 408.15 ± 61.63 and 49.33 ± 11.26 W/m 2 . The high global and diffuse solar radiations were observed during March-May (257.67 ± 34.18 W/m 2 , 65.07 ± 11.20 W/m 2 ) whereas low global and diffuse solar radiations during monsoon months (137.66 ± 12.41, 33.47 ± 7.44 W/m 2 ). In the case of extraterrestrial solar radiation was high in the month of December (472.92 ± 0.67 W/m 2 ) and low in the month of June (312.87 ± 2.58 W/m 2 ).

Detecting drift bias and exposure errors in solar and photosynthetically active radiation data

All-black thermopile pyranometers are commonly used to measure solar radiation. Ensuring that the sensors are stable and free of drift is critical to accurately measure small variations in global solar irradiance at the Earth’s surface (K↓), which is a potential driver of changes in surface temperature. We demonstrate that the decreased responsivities of Eppley PSP pyranometers of −1.5%y−1, or −0.38% (GJm−2)−1, were accompanied by a change in its spectral response owing to a discoloration of the sensing element. These observations motivated further work to develop routines to detect probable pyranometer drift in historical time-series. The temporal trends in the following ratios were used to detect pyranometer sensor drift: photosynthetically active radiation (PAR) to K↓, K↓ to KEX (extraterrestrial radiation at the top of the atmosphere) and PAR to KEX. Data from 8 AmeriFlux sites spanning latitudes from ∼32 to 54°N were examined in this analysis. Probable drift in either a pyranometer or PAR sensor was identified at 5 of the 8 sites. The magnitude of the drift represented changes of 0.15–0.85%y−1, which is sufficient to obscure actual trends in K↓, although these should be considered conservative low end drift estimates, given that we were not making comparisons to co-located higher grade instruments. Deployment exposure errors caused by sensor shading were also discovered by comparing the daily correlations between (i) K↓ and KEX and (ii) PAR and KEX. Sensors drifting at rates similar to our defective PSP over a 5 year period would contribute to an underestimation of available energy of ∼70Wm−2, which is non-trivial in the context of assessing eddy covariance energy balance closure, employing Penman-Monteith or Bowen ratio methods or calculating albedo radiative forcings. Given that probable drift was identified at multiple AmeriFlux sites, we recommend enhancing network access to calibration services that are traceable to a high quality gold standard.

Effects of cloud, atmospheric water vapor, and dust on photosynthetically active radiation and total solar ra-diation in a Mongolian grassland

Photosynthetically active radiation (PAR) is an important input parameter for estimating plant produc- tivity due to its key role in the growth and development of plants. However, a worldwide routine network for sys- tematic PAR measurements is not yet established, and PAR is often calculated as a constant fraction of total solar radiation (SR). Although the ratio of PAR to SR (PAR/SR) has been reported from many places, few studies have been performed for dry regions. The present study was therefore carried out in an arid region of Mongolia to obtain PAR/SR and examine its dependency on sky clearness (the clearness index), water vapor in the atmosphere and aeolian dust. Continuous measurements of PAR and SR were taken every one second using quantum and pyranometer sensors, respectively, and the readings were averaged and recorded at intervals of 30 minutes for a period of 12 months. The lowest monthly mean daily PAR/SR occurred in April (0.420), while the highest ratio was observed in July (0.459). Mean daily PAR/SR during plant growing season (May−August) was estimated to be 0.442, which could be useful for modeling plant productivity in the study area. The annual mean daily PAR/SR (0.435) was lower than the values reported in many previous studies. This difference could be explained with the regional variation in climate: i.e. drier climatic condition in the study area. PAR/SR was negatively correlated with the clearness index (r= -0.36, P<0.001), but positively with atmospheric water vapor pressure (r=0.47, P<0.001). The average PAR/SR was significantly lower (P=0.02) on the dusty days compared to the non-dust days. Water vapor in the atmosphere was shown to be the strongest factor in the variation of PAR/SR. This is the first study examining PAR/SR under a semi-arid condition in Mongolia.

Developing a Device to Quantify Light Penetration in Turfgrass Canopies

Light penetration measurements have not been possible in turfgrass environments due to the large size of commercial light bars relative to the low height of the turfgrass canopy. A light bar was designed and constructed for use in turfgrass canopies mowed as short as 1.3 cm. The instrument uses four miniature solar cells connected in parallel and mounted to a high density polyethylene (HDPE) bar measuring 3.5‐mm wide, 6‐mm tall, and 200‐mm long. The constructed light bar was calibrated against a Li‐Cor (Li‐Cor, Lincoln, NE) pyranometer sensor and obtained a relationship of Y = 1.0293e16.039x with an R2 value of 0.96. Data demonstrate measured differences in light penetration through an annual ryegrass (Lolium multiflorum Lam.) canopy maintained at three mowing heights. Light penetration measured at the base of annual ryegrass canopies maintained at cutting heights of 3.2, 5.7. and 8.3 cm amounted to 5.36 to 7.48%, 1.21 to 3.43%, and 0.10 to 0.40%, of full sunlight, respectively. This device should allow researchers the ability to assess canopy light penetration in low‐growing vegetation including turfgrasses.

The assessment of four different correction models applied to the diffuse radiation measured with a shadow ring using global and normal beam radiation measurements for Beer Sheva, Israel

The measurement of the diffuse radiation incident on a horizontal surface, a priori a straightforward task, is fraught with difficulties. It is possible to measure the diffuse radiation by three different techniques: two of which measure it directly and the third indirectly. The most accurate is the indirect one, which is based upon the concurrent measurements of the horizontal global and the normal incidence beam radiation. The disadvantage of this being the relatively expensive tracking system required for measuring the latter. The diffuse radiation can be measured directly with a pyranometer outfitted with either an occulting disk or shadow ring, which prevent the beam radiation from impinging on the pyranometer sensor. The occulting disk can provide accurate measurements of the diffuse radiation but it requires a relatively expensive sun tracking system in the east–west axis. The shadow ring is a stationary device with regard to the east–west axis and blocks the beam radiation component by creating a permanent shadow on the pyranometer sensor. The major disadvantage of the shadow ring is that it also blocks that portion of the diffuse radiation obscured by the shadow ring. This introduces a measurement error that must be corrected to account for that portion of the sky obscured by the shadow band. In addition to this geometric correction factor there is a need to correct for anisotropic sky conditions. Four correction models have been applied to the data for Beer Sheva, Israel and the results have been evaluated both graphically and statistically. An attempt has been made to score the relative performance of the models under different sky conditions.

Sources of errors in measurements of PAR

Due to optical processes in the atmosphere the spectral distribution of global, direct solar and diffuse radiation is different and depends on solar elevation, atmosphere transparency etc. Because of various optical properties of phytoelements, the spectral distribution of penetrated and reflected radiation differs from that of incoming radiation. Owing to radiative transfer processes, photosynthetically active radiation (PAR) and its proportion in integral solar radiation is not constant. The aim of the paper is to study theoretically these changes and to estimate systematic errors caused by deviation of the spectral sensitivity of pyranometers and PAR sensors from the spectral sensitivity of ideal sensors. The spectral distribution of radiation was estimated by combining different literature data and the spectral sensitivity of a typical pyranometer using available data for spectral transparency of glass domes and spectral reflectivity of black paints. Simultaneous use of energetic and quantum treatments of radiation in biogeophysics and subsequent existence of different definitions of PAR is a source of uncertainties and misunderstanding. The basic concepts, units and conversion factors between integral radiation and PAR, as well PAR efficiency for different kinds of solar radiation, and spectral corrections for some radiation sensors will be discussed below. Our calculations show that the conversion factor U PAR is 1–3% higher for penetrated radiation and about 6% higher for reflected radiation compared with U PAR Q=0.219 W s μmol −1 for global radiation under a cloudless sky. Due to the different spectral sensitivity of ideal energetic and ideal quantum sensors for PAR, the radiation measured through them differs 3–13% depending on the kind of radiation. Hence PAR quantum efficiency is 3–13% higher when PAR is defined as measured by the ideal energetic PAR sensor than when it is estimated by the ideal quantum PAR sensor. Their quantum efficiency depends essentially on the kind of radiation: for diffuse radiation it is increased by 13% but for reflected radiation it is decreased to about one fourth compared with global and direct solar radiation. For penetrated global radiation, quantum efficiency decreases rapidly with canopy depth, being 8–9 times lower at the bottom of a dense canopy than above it. For the LI-COR LI-190SA Quantum Sensor, systematic spectral errors do not exceed 1%. For the Kipp and Zonen PAR LITE sensor, errors are between 1 and 8% depending on the kind of radiation. For the LI-COR LI-200SA Pyranometer Sensor, systematic spectral errors for the global radiation reflected or penetrated by the canopy are high (20–40%), and this instrument cannot be recommended for measurements inside the canopy as is warned also by the manufacturers.