Simulation of global solar radiation based on cloud observations

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Simulation of global solar radiation based on cloud observations"

Transcription

1 Solar Energy 78 (25) Simulation of global solar radiation based on cloud observations Jimmy S.G. Ehnberg *, Math H.J. Bollen Department of Electric Power Engineering, Chalmers University of Technology, Göteborg SE , Sweden Received 6 August 23; received in revised form 23 August 24; accepted 23 August 24 Available online 14 October 24 Communicated by: Associate Editor Pierre Ineichen Abstract Astochastic model for simulating global solar radiation on a horizontal surface has been developed for use in power systems reliability calculations. The importance of an appropriate model for global solar radiation has increased with the increased use of photovoltaic power generation. The global solar radiation shows not only regular yearly and daily variations but also a random behaviour. The yearly and daily variations can be described in a deterministic way while the random behaviour has a high correlation with the state of the atmosphere. The astronomic effects can easily be described mathematical with only some minor simplifications but the atmospheric effects are more complicated to describe. The transmittivity of solar radiation in the atmosphere depends on various factors, e.g. humidity, air pressure and cloud type. By using cloud observations as input for the simulations, the local meteorological conditions can be accounted for. The model is usable for any geographical location if cloud observations are available at the location or at locations with similar climatological conditions. This is especially useful for development countries where longterm solar radiation measurement can be hard to obtain. Cloud observations can be performed without any expensive equipment and have been a standard parameter for many years throughout the world. Standard observations are done according to the Oktas-scale. It is the interval between observations that sets the resolution of the simulation: the observations are normally only every hour or every third hour. The model can easily be combined with cloud coverage simulations, has been proposed, for a more general model. For some calculations higher resolution may be needed. This can be obtained by including a stochastic model for the short-term variations and simple model has been proposed. Errors and limitations of the model are estimated and discussed. Ó 24 Elsevier Ltd. All rights reserved. Keywords: Solar power; Markov model; Cloud coverage 1. Introduction * Corresponding author. Tel.: ; fax: address: (J.S.G. Ehnberg). In rural areas of developing countries the interest in electrification has increased over the last few years resulting in an improved standard of living. This is confirmed by many ongoing research programs. The problem of electrification of remote rural areas may be solved by 38-92X/$ - see front matter Ó 24 Elsevier Ltd. All rights reserved. doi:1.116/j.solener

2 158 J.S.G. Ehnberg, M.H.J. Bollen / Solar Energy 78 (25) Nomenclature d s vector of the solar declination angles over a time period determined by d (rad) U r the tilt of the earthõs axis relative the orbital plane of the earth around the sun, U r =.49 rad C C=2p (rad) d vector of days of the year for the time period of the simulation (days) d r the day of the year at summer solstice, 22nd of June for non-leap years (days) d y total number of days in a year (days) w vector of local elevation angle angles over a time period determined by d (rad) t UTC Co-ordinated Universal Time (h) t d hours in a day (h) / latitude of the location, positive north of the equator (rad) k e longitude of the location, positive west of Greenwich (rad) G h vector of global solar radiation (hourlyscale) over a time period determined by d (W/m 2 ) G min global solar radiation (minute-scale) over a time period determined by d (W/m 2 ) N number of Oktas L, a, a i, i =, 1, 3 empirical determined constants (W/m 2 ) e statistically varying term, e N (m,r 2 ) k ij estimated transition probability from i to j f ij number of transitions from state i to j bk estimated transition probability matrix the use of autonomous electric power systems, supplied exclusively by environmental friendly power sources, e.g. solar power. Solar power is a suitable source because of the high solar radiation, available in many developing countries and the low maintenance requirements. The interest for solar power has also increased in other parts of the world because of the need of more environmental friendly power generation to secure both the future power demand and the survival of our planet. Several models have been proposed for generation of global radiation. The random nature of global solar radiation is included in all proposals, but the way of implementing this in a model varies significantly. In (Amato et al., 1986; Albizzati et al., 1997; Balouktsis et al. 1989) they model daily global solar radiation (thus the yearly variations) but a higher resolution of the simulation is needed for photovoltaic power generation in an autonomous electric power system. Such model would be applicable in a system with a storage capability higher than the daily load demand. The models of (Amato et al., 1986; Balouktsis et al., 1989) requires several years of solar radiation measurements, which are for most locations not available. The model proposed by (Albizzati et al., 1997) is adapted for clear sky conditions but the authors mentioned the importance of the cloud coverage. In (Graham and Hollands, 199) hourly radiation has been modelled but the model could be difficult to apply due to the data requirements. Monthly average values of global radiation are needed which can only be obtained from long time measurements. Another model is proposed in (Balouktsis and Tsalides, 1986) but the problem with the input of the model remains. Alocation-dependent factor is used which depends on the probability distribution of the solar radiation. This model can again only be used when a large amount of solar radiation data is available. Outside the atmosphere the solar radiation can accurately be determined (Stull, 1995) and the atmosphere will induce the randomness (Graham and Hollands, 199). The transmittivity of solar radiation in the atmosphere depends on various factors, e.g. humidity, air pressure and cloud type. Afactor that has a great impact on the transmittivity is the cloud coverage (Nielsen et al., 1981; Albizzati et al., 1997). By assuming a deterministic relation between cloud coverage and hourly global solar radiation, the need for measurement of the latter disappears. Cloud observations can be used because of the simplicity of measuring, no expensive equipment is needed. The level of cloudiness is expressed in Oktas, which describes how many eight parts of the sky that are covered with clouds (Jones, 1992). By combining the solar radiation model with a model of simulating cloud coverage the simulation method could be even more suitable. Models for simulating cloud coverage and the solar radiation have been investigated by several authors, e.g. (Gu et al., 21; Badescu, 22). In (Gu et al., 21) the focus is on spectral simulation, which has a great importance for the use of solar panels but requires detailed and extensive knowledge of the atmosphere and its contents. (Badescu, 22) has reviewed some simple models and concluded that even simple or very simple (words used by the author) models can be useful. The author has proposed a new kind of sky model but has lost the simplicity of the model that is needed for use in power system studies.

3 J.S.G. Ehnberg, M.H.J. Bollen / Solar Energy 78 (25) The solar radiation distribution is expected to be similar in areas with similar climatological conditions (Balouktsis and Tsalides, 1986). That means that this method could be used when cloud observations are available for an area with similar climatological conditions. In reliability simulations for power systems without storage capacity, simulation data with higher resolution than one hour is needed in some cases. This is the case when short-duration interruptions (less than one half hour) are a concern. In this paper a model for simulating six minutes values of global solar radiation without any geographical restrictions is proposed and discussed. The method uses cloud coverage observations as input. Amethod of generating cloud coverage by using a discrete Markov model is also proposed. 2. Astronomical part of the model Astronomical effects are due to the earth rotation around the sun and the rotation of the earth around its axis. The seasonal and daily variations can be described by Eqs. (1) and (2) (Stull, 1995). The equation for the seasonal effects (1) is an approximation under the assumption of circular orbit of the earth around the sun. This assumption is allowed because the excentricity is only.7 and the results are only used in stochastic ways. Eq. (2) describes the daily effects and is dependent on the geographical location through latitude and longitude. Eq. (2) contains time dependence. Correlation is needed with local time to be used in power systems studies where comparisons with often time depended load are of importance. d s ¼ U r cos Cðd d rþ ð1þ d y sin w ¼ sin / sin d s cos / cos d s cos C t UTC t d 3. Atmospherical part of the model k e ð2þ The randomness in this simulation model for global solar radiation is introduced in this section. The importance of the randomness in the atmosphere is also discussed in (Graham and Hollands, 199). An empirically determined relationship between the global solar radiation and the cloud coverage, Eq. (3) was obtained by (Nielsen et al., 1981), after many years of cloud observations, solar elevation measurements and global solar radiation measurements. The obtained relationship reads as follows: G ¼ a ðnþþa 1 ðnþ sin w þ a 3 ðnþsin 3 w LðNÞ ð3þ aðnþ The values of the constants L(N), a(n) and a i, i =,1,3, in Eq. (3) are given in Table 1 and the elevation angle from Eq. (2) can be used. In Fig. 1 the global solar radiation is presented as a function of the solar elevation angle for the nine possible values of cloud coverage in the Oktas-scale. Note that even for a fully clouded sky, a non-negligible part of the solar radiation reaches the solar panel (about 25 %). In (Nielsen et al., 1981) it was found that the standard error of the estimation was less then 8 W/m 2 and has a square correlation coefficient of approx..9 when compared with other sites. The model does not include extreme values. However, this has low influence when using time average values. If the global radiation is below zero in Eq. (3) it should be set to zero according to Eq. (4). If the radiation is negative it is from the surface of the earth upwards. This radiation has another frequency spectrum and will not generate any power from solar panels. This situation will occur during nighttime and for low elevation angles. if w i < org h ðiþ < then G h ðiþ ¼ 8i ð4þ Table 1 The empirical determined coefficients for (3) N a a 1 a 3 a L Sine of the Solar Elevation Angle Fig. 1. The relationship between global solar radiation and the solar elevations angle for different cloud coverage

4 16 J.S.G. Ehnberg, M.H.J. Bollen / Solar Energy 78 (25) By examining global solar radiation measurements it can be seen that the radiation varies within a one-hour period. Introducing a statistically varying term according to Eq. (5) could simulate this phenomenon. This statistical term (e) was set to have the same distribution as the short duration variations seen in the measurements. G min ¼ G h þ e ð5þ The statistically varying term can be estimated through cross validation, the so-called hold out method proposed by (Hjort, 1995). The deviation from the hourly mean values for daytime can be fitted to a normal distribution and the mean value and the standard deviation estimated. Deviation [%] Cloud coverage [Oktas] 4. Cloud coverage simulation To be able to perform a simulation over a longer period then the available cloud coverage data some kind of generation of stochastic cloud coverage data is needed. If it can be assumed that the current level of cloud coverage is only depended on the previous value, a discrete Markov model can be used. With this assumption a model with nine different states ( 8), corresponding to the nine levels in the Oktas scale is proposed. The transitions probability matrix ( bk) can be estimated from measured cloud coverage data. The transition probabilities can by estimated in many ways but the most intuitively is: ^k ij ¼ f ij P 8 k¼ f ik 2 3 ^k ^k1 ^k8 ^k 1 ^k11 ^k18 bk ¼ ^k 8 ^k81 ^k88 ð6þ ð7þ This is a maximum likelihood estimation if the chain has stationarity, as shown by (Macdonald and Zucchini, 1997). Astart value can be arbitrary chosen since the starting condition has no influence in the long run. The deviation between measured and simulated cloud coverage data is shown in Fig. 2 and maximum deviation is 1.5 %, for Oktas. Cloud coverage data for Göteborg was used in the figure. 5. Case study,göteborg To show the applicability of the model a case study has been made. The case study was made for Göteborg (Lat N, Long E). Göteborg is normally minus one hour from Greenwich, which is included in the following calculations. Fig. 2. The deviation between measurements and simulations for each cloud coverage value. The error band indicates the standard deviation. The transition matrix for the Markov model for the cloud coverage simulation was estimated from measurements of cloud coverage obtained during the period from 1973 to The transition probabilities were estimated according to Eq. (6). They were estimated every three hours because the available cloud coverage observations was done with this interval. The estimated transition matrix ( bk) for Göteborg is presented below, with values given as a percentage :8 22:5 7:1 4:7 2:7 2:3 1:7 2:6 2:6 15:5 45:5 14: 9:1 4:3 3:7 3:2 3: 1:5 7: 24:5 23:4 15:3 8:8 7:2 6:2 5:4 2:2 3:8 13:4 17:7 2:3 12:6 1:6 9: 9:1 3:4 bk ¼ 2:2 8:5 12:1 15:9 16:2 14:4 13:4 13:2 4:2 1:5 5:1 8:1 12:2 12:6 17:3 18:7 18:3 6:2 1: 3: 5:2 7:4 9:5 14:2 22:2 28: 9: :6 2: 2:3 3: 3:9 6:3 11:3 5:3 2:45 :5 :7 :8 1:1 1:3 2: 3:8 13:5 76:3 ð8þ The mean value of the deviation between the simulated and the observed cloud coverage values is shown in Fig. 2. The mean deviation for every cloud coverage value and the standard deviation are shown. The mean values and standard deviations are calculated from ten independently made simulations. From the figure the conclusion is drawn that the error is around 1 %, and that the model is an acceptable model of the measurement. This cloud coverage simulation was used together with the calculated solar elevation angle to obtain the global solar radiation for Göteborg according to Eq. (3). Since the meteorological data used for the estimation of the transition probability matrix was only every three hours, a linear interpolation was used to achieve

5 J.S.G. Ehnberg, M.H.J. Bollen / Solar Energy 78 (25) Time [hours] Fig. 5. Comparison between calculated and measured values for a day in June Day of the year Fig. 3. The maximum daily value of the global solar radiation in Göteborg during one year Day of the year Fig. 4. The global solar radiation for a few days in February in Göteborg. hourly values. Fig. 3 shows the result by showing the maximum value for each day during one year. The upper and the lower bound of the distribution correspond to clear sky ( Oktas) and totally cloud covered sky (8 Oktas). Fig. 4 shows the global solar radiation for a few days in February. By adding a statistically varying term, as in Eq. (5), simulated values with a higher time resolution were obtained. For the statistical term, a normal distribution was used with a mean value of zero and a standard deviation of 4 W/m 2. For the results, shown in Fig. 5, measured six-minute mean values of global solar radiation for a single day in June in 1999 were used. Hourly mean values were calculated and then the statistically varying term was added and the result is shown in the same figure as the measured values. Asolid line represents the measured values while the calculated values are presented by a dotted line. The comparison was done for a single day in June. 6. Conclusions Amodel for simulation of global solar radiation based on cloud observations is presented. The advantages of the model are that there are no geographical restrictions to its use and that there is no need for global solar radiation measurements. The model does however require cloud coverage observations over a longer period, but those data are in most cases easier to obtain than solar radiation data. Astochastic model to generate cloud observations for use in simulations was developed. This model only needs to be adapted to a climate similar to the one at the desired geographical location. The errors and limitations of the model effect the usefulness. However, for time average estimations the influence is low and in this model only time average estimations are of interest. Acknowledgments This project is financially supported by the Alliance for Global Substantiality. The authors also wish to thank SMHI (Swedish Meteorological and Hydrological Institute) for providing meteorological data. References Albizzati, E., Rossetti, G., Alfano, O., Measurements and predictions of solar radiation incident on horizontal surfaces at Santa Fe, Argentina (31 39 S, 6 43 W). Renewable Energy 4,

6 162 J.S.G. Ehnberg, M.H.J. Bollen / Solar Energy 78 (25) Amato, U., Andretta, B., Bartoli, B., Coluzzi, B., Cuomo, V., Markov processes and Fourier analysis as a tool to describe and simulate daily solar radiation. Int. J. Solar Energy 37, Badescu, V., 22. Anew kind of cloudy sky model to compute instantaneous values of diffuse and global solar irradiance. Theor. Appl. Climatol. 72, Balouktsis, A., Tsalides, P., Stochastic simulation model of hourly total solar radiation. Int. J. Solar Energy 37, Balouktsis, A., Tsanakas, D., Vachtsevanos, G., Stochastic modelling of daily global solar radiation. Int. J. Solar Energy 7, 1 1. Graham, V., Hollands, K., 199. Amethod to generate synthetic hourly solar radiation globally. Int. J. Solar Energy 44, Gu, L., Fuentes, J.D., Garstang, M., Da Silva, J.T., Heitz, R., Sigler, J., Shugart, H.H., 21. Cloud modulation of solar irradiance at a pasture site in southern Brazil. Agric. Forest Meteorol. 16, Hjort, U., Computer Intensive Statistical Methods: Validation, Model Selection and Bootstrap. Chapman & Hall, London. Jones, P., Cloud-cover distribution and correlations. J. Appl. Meterol. 31, Macdonald, I., Zucchini, W., Hidden Markov and other Models for Discrete valued Time Series. Chapman & Hall, London. Nielsen, L., Prahm, L., Berkowicz, R., Conradsen, K., Net incoming radiation estimated from hourly global radiation and/or cloud observations. J. Climatol. 1, Stull, R.B., Meteorology Today For Scientists and Engineers: ATechnical Companion Book. West Publishing Company, Minneapolis/St. Paul.

Sun Earth Relationships

Sun Earth Relationships 1 ESCI-61 Introduction to Photovoltaic Technology Sun Earth Relationships Ridha Hamidi, Ph.D. Spring (sun aims directly at equator) Winter (northern hemisphere tilts away from sun) 23.5 2 Solar radiation

More information

Renewable Energy. Solar Power. Courseware Sample 86352-F0

Renewable Energy. Solar Power. Courseware Sample 86352-F0 Renewable Energy Solar Power Courseware Sample 86352-F0 A RENEWABLE ENERGY SOLAR POWER Courseware Sample by the staff of Lab-Volt Ltd. Copyright 2009 Lab-Volt Ltd. All rights reserved. No part of this

More information

ESCI 107/109 The Atmosphere Lesson 2 Solar and Terrestrial Radiation

ESCI 107/109 The Atmosphere Lesson 2 Solar and Terrestrial Radiation ESCI 107/109 The Atmosphere Lesson 2 Solar and Terrestrial Radiation Reading: Meteorology Today, Chapters 2 and 3 EARTH-SUN GEOMETRY The Earth has an elliptical orbit around the sun The average Earth-Sun

More information

Solar Radiation. ELEG620: Solar Electric Systems University of Delaware, ECE Spring 2009 S. Bremner

Solar Radiation. ELEG620: Solar Electric Systems University of Delaware, ECE Spring 2009 S. Bremner Solar Radiation Solar Radiation Outline Properties of radiation: Summary of equations, terms, concepts Solar Spectra Terrestrial Solar Radiation: Effects of atmosphere, angular dependence of radiation,

More information

Earth-Sun Geometry. Introduction: Earth-Sun Geometry

Earth-Sun Geometry. Introduction: Earth-Sun Geometry Earth-Sun Geometry Readings: A&B: Ch. 2 (p. 42-50) CD Tutorial: Earth-Sun Geometry www: 2. Earth- Sun Geometry Topics 1. Introduction 2. Orbital Geometry a) Rotation b) revolution 3. Seasons a) Solstices

More information

Full credit for this chapter to Prof. Leonard Bachman of the University of Houston

Full credit for this chapter to Prof. Leonard Bachman of the University of Houston Chapter 6: SOLAR GEOMETRY Full credit for this chapter to Prof. Leonard Bachman of the University of Houston SOLAR GEOMETRY AS A DETERMINING FACTOR OF HEAT GAIN, SHADING AND THE POTENTIAL OF DAYLIGHT PENETRATION...

More information

SATELLITE IMAGES IN ENVIRONMENTAL DATA PROCESSING

SATELLITE IMAGES IN ENVIRONMENTAL DATA PROCESSING SATELLITE IMAGES IN ENVIRONMENTAL DATA PROCESSING Magdaléna Kolínová Aleš Procházka Martin Slavík Prague Institute of Chemical Technology Department of Computing and Control Engineering Technická 95, 66

More information

Solar Angles and Latitude

Solar Angles and Latitude Solar Angles and Latitude Objectives The student will understand that the sun is not directly overhead at noon in most latitudes. The student will research and discover the latitude ir classroom and calculate

More information

APPENDIX D: SOLAR RADIATION

APPENDIX D: SOLAR RADIATION APPENDIX D: SOLAR RADIATION The sun is the source of most energy on the earth and is a primary factor in determining the thermal environment of a locality. It is important for engineers to have a working

More information

Sunlight and its Properties. EE 495/695 Y. Baghzouz

Sunlight and its Properties. EE 495/695 Y. Baghzouz Sunlight and its Properties EE 495/695 Y. Baghzouz The sun is a hot sphere of gas whose internal temperatures reach over 20 million deg. K. Nuclear fusion reaction at the sun's core converts hydrogen to

More information

PHSC 3033: Meteorology Seasons

PHSC 3033: Meteorology Seasons PHSC 3033: Meteorology Seasons Changing Aspect Angle Direct Sunlight is more intense and concentrated. Solar Incidence Angle is Latitude and Time/Date Dependent Daily and Seasonal Variation Zenith There

More information

Study and Evaluation of Solar Energy Variation in Nigeria

Study and Evaluation of Solar Energy Variation in Nigeria Study and Evaluation of Solar Energy Variation in Nigeria Engr. C. O. Osueke (Ph.D, Post Ph.D) 1, Engr. (Dr) P. Uzendu 2, Engr. I. D. Ogbonna 3 1 Department of Mechanical Engineering, Landmark University,

More information

Figure 1: A backpackers solar panel and rechargeable batteries.

Figure 1: A backpackers solar panel and rechargeable batteries. SOLAR ENERGY TAKE A SPHERICAL COW Stephen A. Wilkerson Army Research Laboratory Vehicles Technology Directorate Aberdeen Proving Grounds, MD 21005 stephen.a.wilkerson.civ@mail.mil Russell Park Department

More information

Chapter 2: Solar Radiation and Seasons

Chapter 2: Solar Radiation and Seasons Chapter 2: Solar Radiation and Seasons Spectrum of Radiation Intensity and Peak Wavelength of Radiation Solar (shortwave) Radiation Terrestrial (longwave) Radiations How to Change Air Temperature? Add

More information

Coordinate Systems. Orbits and Rotation

Coordinate Systems. Orbits and Rotation Coordinate Systems Orbits and Rotation Earth orbit. The earth s orbit around the sun is nearly circular but not quite. It s actually an ellipse whose average distance from the sun is one AU (150 million

More information

Solar Tracking Application

Solar Tracking Application Solar Tracking Application A Rockwell Automation White Paper Solar trackers are devices used to orient photovoltaic panels, reflectors, lenses or other optical devices toward the sun. Since the sun s position

More information

SOLAR ENERGY CONVERSION AND PHOTOENERGY SYSTEMS Vol. I - Solar Radiation Energy (Fundamentals) - L. Wald SOLAR RADIATION ENERGY (FUNDAMENTALS)

SOLAR ENERGY CONVERSION AND PHOTOENERGY SYSTEMS Vol. I - Solar Radiation Energy (Fundamentals) - L. Wald SOLAR RADIATION ENERGY (FUNDAMENTALS) SOLAR RADIATION ENERGY (FUNDAMENTALS) L. Centre for Energy and Processes, Ecole des Mines de Paris, France Keywords: Sun, earth, astronomy, radiation, solar constant, energy, irradiance, irradiation, extraterrestrial

More information

Solar Radiation Calculation

Solar Radiation Calculation Solar Radiation Calculation Dr. Mohamad Kharseh E-mail: kharseh@qu.edu.qa mohkh3@hotmail.com 1 Solar Constant Solar Constant is the intensity of the solar radiation hitting one square meter of the Earth

More information

The impact of high latitudes on the optical design of solar systems

The impact of high latitudes on the optical design of solar systems The impact of high latitudes on the optical design of solar systems Mats Rönnelid 1, Björn Karlsson 2 and J M Gordon 3 1 Solar Energy Research Center, Dalarna University, S-781 88 Borlänge, Sweden 2 Vattenfall

More information

SOLAR RADIATION AND YIELD. Alessandro Massi Pavan

SOLAR RADIATION AND YIELD. Alessandro Massi Pavan SOLAR RADIATION AND YIELD Alessandro Massi Pavan Sesto Val Pusteria June 22 nd 26 th, 2015 DEFINITIONS Solar radiation: general meaning Irradiation [Wh/m 2 ]: energy received per unit area Irradiance [W/m

More information

Solar Radiation Prediction and Energy Allocation for Energy Harvesting Base Stations

Solar Radiation Prediction and Energy Allocation for Energy Harvesting Base Stations Solar Radiation Prediction and Energy Allocation for Energy Harvesting Base Stations Yanan Bao, Xiaolei Wang, Xin Liu, Sheng Zhou and Zhisheng Niu Dept. of Computer Science, University of California, Davis

More information

A Novel Method for Predicting the Power Output of Distributed Renewable Energy Resources

A Novel Method for Predicting the Power Output of Distributed Renewable Energy Resources A Novel Method for Predicting the Power Output of Distributed Renewable Energy Resources Aris-Athanasios Panagopoulos1 Joint work with Georgios Chalkiadakis2 and Eftichios Koutroulis2 ( Predicting the

More information

Earth-Sun Relationships. The Reasons for the Seasons

Earth-Sun Relationships. The Reasons for the Seasons Earth-Sun Relationships The Reasons for the Seasons Solar Radiation The earth intercepts less than one two-billionth of the energy given off by the sun. However, the radiation is sufficient to provide

More information

UCCS PES 1620 Solar Energy Lab Seasons Lab Fall 2014 name:

UCCS PES 1620 Solar Energy Lab Seasons Lab Fall 2014 name: UCCS PES 1620 Solar Energy Lab Seasons Lab Fall 2014 name: 1. During the winter in the Northern Hemisphere, the "land of the midnight sun" would be found a. at high latitudes. b. at middle latitudes. c.

More information

Earth's Revolution and its Seasons

Earth's Revolution and its Seasons NAME PER PART 1 - Earth's Revolution: Earth's Revolution and its Seasons Examine the Figure 1 above. Answer these questions. 1. True/False: As Earth revolves around the Sun it is always tilted toward the

More information

Chapter 2. Mission Analysis. 2.1 Mission Geometry

Chapter 2. Mission Analysis. 2.1 Mission Geometry Chapter 2 Mission Analysis As noted in Chapter 1, orbital and attitude dynamics must be considered as coupled. That is to say, the orbital motion of a spacecraft affects the attitude motion, and the attitude

More information

2 Absorbing Solar Energy

2 Absorbing Solar Energy 2 Absorbing Solar Energy 2.1 Air Mass and the Solar Spectrum Now that we have introduced the solar cell, it is time to introduce the source of the energy the sun. The sun has many properties that could

More information

SOLAR CALCULATIONS (2)

SOLAR CALCULATIONS (2) OLAR CALCULATON The orbit of the Earth is an ellise not a circle, hence the distance between the Earth and un varies over the year, leading to aarent solar irradiation values throughout the year aroximated

More information

Solar Flux and Flux Density. Lecture 3: Global Energy Cycle. Solar Energy Incident On the Earth. Solar Flux Density Reaching Earth

Solar Flux and Flux Density. Lecture 3: Global Energy Cycle. Solar Energy Incident On the Earth. Solar Flux Density Reaching Earth Lecture 3: Global Energy Cycle Solar Flux and Flux Density Planetary energy balance Greenhouse Effect Vertical energy balance Latitudinal energy balance Seasonal and diurnal cycles Solar Luminosity (L)

More information

FIRST GRADE 1 WEEK LESSON PLANS AND ACTIVITIES

FIRST GRADE 1 WEEK LESSON PLANS AND ACTIVITIES FIRST GRADE 1 WEEK LESSON PLANS AND ACTIVITIES UNIVERSE CYCLE OVERVIEW OF FIRST GRADE UNIVERSE WEEK 1. PRE: Describing the Universe. LAB: Comparing and contrasting bodies that reflect light. POST: Exploring

More information

Impacts of large-scale solar and wind power production on the balance of the Swedish power system

Impacts of large-scale solar and wind power production on the balance of the Swedish power system Impacts of large-scale solar and wind power production on the balance of the Swedish power system Joakim Widén 1,*, Magnus Åberg 1, Dag Henning 2 1 Department of Engineering Sciences, Uppsala University,

More information

Scholars Research Library. Estimation of global solar radiation using cloud cover and surface temperature in some selected cities in Nigeria

Scholars Research Library. Estimation of global solar radiation using cloud cover and surface temperature in some selected cities in Nigeria Available online at www.scholarsresearchlibrary.com Archives of Physics Research, 2011, 2 (3):99-109 (http://scholarsresearchlibrary.com/archive.html) ISSN : 0976-0970 CODEN (USA): APRRC7 Estimation of

More information

Newton s Law of Gravity

Newton s Law of Gravity Gravitational Potential Energy On Earth, depends on: object s mass (m) strength of gravity (g) distance object could potentially fall Gravitational Potential Energy In space, an object or gas cloud has

More information

Lectures Remote Sensing

Lectures Remote Sensing Lectures Remote Sensing ATMOSPHERIC CORRECTION dr.ir. Jan Clevers Centre of Geo-Information Environmental Sciences Wageningen UR Atmospheric Correction of Optical RS Data Background When needed? Model

More information

Running the Electric Meter Backwards: Real-Life Experience with a Residential Solar Power System

Running the Electric Meter Backwards: Real-Life Experience with a Residential Solar Power System Running the Electric Meter Backwards: Real-Life Experience with a Residential Solar Power System Brooks Martner Lafayette, Colorado University of Toledo Spring 2015 PHYS 4400 - Principles and Varieties

More information

IMPACT EVALUATION OF PV GENERATION ON LV NETWORKS

IMPACT EVALUATION OF PV GENERATION ON LV NETWORKS IMPACT EVALUATION OF PV GENERATION ON LV NETWORKS Antti Supponen, Sami Repo Department of Electrical Engineering Tampere University of Technology Tampere, Finland antti.supponen@tut.fi, sami.repo@tut.fi

More information

ATM S 111, Global Warming: Understanding the Forecast

ATM S 111, Global Warming: Understanding the Forecast ATM S 111, Global Warming: Understanding the Forecast DARGAN M. W. FRIERSON DEPARTMENT OF ATMOSPHERIC SCIENCES DAY 1: OCTOBER 1, 2015 Outline How exactly the Sun heats the Earth How strong? Important concept

More information

Exploring Solar Energy Variations on Earth: Changes in the Length of Day and Solar Insolation Through the Year

Exploring Solar Energy Variations on Earth: Changes in the Length of Day and Solar Insolation Through the Year Exploring Solar Energy Variations on Earth: Changes in the Length of Day and Solar Insolation Through the Year Purpose To help students understand how solar radiation varies (duration and intensity) during

More information

Short-term solar energy forecasting for network stability

Short-term solar energy forecasting for network stability Short-term solar energy forecasting for network stability Dependable Systems and Software Saarland University Germany What is this talk about? Photovoltaic energy production is an important part of the

More information

The following words and their definitions should be addressed before completion of the reading:

The following words and their definitions should be addressed before completion of the reading: Seasons Vocabulary: The following words and their definitions should be addressed before completion of the reading: sphere any round object that has a surface that is the same distance from its center

More information

PHYSICAL GEOGRAPHY, EXAM 1 (CH 1-4) STUDY GUIDE

PHYSICAL GEOGRAPHY, EXAM 1 (CH 1-4) STUDY GUIDE PHYSICAL GEOGRAPHY, EXAM (CH -4) STUDY GUIDE NOTE: This guide is to cover some of the main topics we have discussed but does not cover everything on the exam. To do well, you need to carefully read and

More information

World Geography. Chapter 3 Section 1

World Geography. Chapter 3 Section 1 World Geography By Richard G. Boehm, Ph.D. Chapter 3 Section 1 Climates of the Earth Earth-Sun Relationships June 26, 2006 Stephen Mathews 1 Weather The condition of the bottom layer of the earth s atmosphere

More information

Solar Energy Systems. Matt Aldeman Senior Energy Analyst Center for Renewable Energy Illinois State University

Solar Energy Systems. Matt Aldeman Senior Energy Analyst Center for Renewable Energy Illinois State University Solar Energy Solar Energy Systems Matt Aldeman Senior Energy Analyst Center for Renewable Energy Illinois State University 1 SOLAR ENERGY OVERVIEW 1) Types of Solar Power Plants 2) Describing the Solar

More information

Seasonal & Daily Temperatures. Seasons & Sun's Distance. Solstice & Equinox. Seasons & Solar Intensity

Seasonal & Daily Temperatures. Seasons & Sun's Distance. Solstice & Equinox. Seasons & Solar Intensity Seasonal & Daily Temperatures Seasons & Sun's Distance The role of Earth's tilt, revolution, & rotation in causing spatial, seasonal, & daily temperature variations Please read Chapter 3 in Ahrens Figure

More information

Chapter 1: Introduction to Earth. McKnight s Physical Geography: A Landscape Appreciation, Tenth Edition, Hess

Chapter 1: Introduction to Earth. McKnight s Physical Geography: A Landscape Appreciation, Tenth Edition, Hess Chapter 1: Introduction to Earth McKnight s Physical Geography: A Landscape Appreciation, Tenth Edition, Hess Introduction to Earth Geography as a Field of Learning Science and Geography The Environmental

More information

Name: Section: Date: EXERCISE A: EARTH MOTIONS AND EARTH-SUN RELATIONS

Name: Section: Date: EXERCISE A: EARTH MOTIONS AND EARTH-SUN RELATIONS Name: Section: Date: EXERCISE A: EARTH MOTIONS AND EARTH-SUN RELATIONS REFERENCE: Textbook: Geosystems: An Introduction to Physical Geography Ch.1 Essentials of Geography and Ch.2 Solar Energy to Earth

More information

Essential Question. Enduring Understanding

Essential Question. Enduring Understanding Earth In Space Unit Diagnostic Assessment: Students complete a questionnaire answering questions about their ideas concerning a day, year, the seasons and moon phases: My Ideas About A Day, Year, Seasons

More information

2. EARTH-SUN GEOMETRY

2. EARTH-SUN GEOMETRY G109: 2. Earth-Sun Geometry 1 2. EARTH-SUN GEOMETRY Reading Assignment: A&B: Ch. 2 (p. 53-61) CD: Tutorial 1 Solar Geometry LM: Lab. 5 www: Earth-Sun Geometry Introduction The Sun is the only important

More information

Global Seasonal Phase Lag between Solar Heating and Surface Temperature

Global Seasonal Phase Lag between Solar Heating and Surface Temperature Global Seasonal Phase Lag between Solar Heating and Surface Temperature Summer REU Program Professor Tom Witten By Abstract There is a seasonal phase lag between solar heating from the sun and the surface

More information

Today. Appearance of the Sky. Orientation. Motion of sky. Seasons. Precession. Phases of the Moon

Today. Appearance of the Sky. Orientation. Motion of sky. Seasons. Precession. Phases of the Moon Today Appearance of the Sky Orientation Motion of sky Seasons Precession Phases of the Moon The Appearance of the Sky The Local Sky An object s altitude (above horizon) and direction (along horizon) specify

More information

Solarstromprognosen für Übertragungsnetzbetreiber

Solarstromprognosen für Übertragungsnetzbetreiber Solarstromprognosen für Übertragungsnetzbetreiber Elke Lorenz, Jan Kühnert, Annette Hammer, Detlev Heienmann Universität Oldenburg 1 Outline grid integration of photovoltaic power (PV) in Germany overview

More information

The Next Generation Flux Analysis: Adding Clear-Sky LW and LW Cloud Effects, Cloud Optical Depths, and Improved Sky Cover Estimates

The Next Generation Flux Analysis: Adding Clear-Sky LW and LW Cloud Effects, Cloud Optical Depths, and Improved Sky Cover Estimates The Next Generation Flux Analysis: Adding Clear-Sky LW and LW Cloud Effects, Cloud Optical Depths, and Improved Sky Cover Estimates C. N. Long Pacific Northwest National Laboratory Richland, Washington

More information

SOLAR RADIATION PREDICTION. the need and effectiveness of a delicate issue

SOLAR RADIATION PREDICTION. the need and effectiveness of a delicate issue SOLAR RADIATION PREDICTION the need and effectiveness of a delicate issue ABOUT THE SPEAKER Fatih SERTTAŞ (Electrical and Electronics Engineer) is a research assistant in Afyon Kocatepe University, TURKEY.

More information

For further information, and additional background on the American Meteorological Society s Education Program, please contact:

For further information, and additional background on the American Meteorological Society s Education Program, please contact: Project ATMOSPHERE This guide is one of a series produced by Project ATMOSPHERE, an initiative of the American Meteorological Society. Project ATMOSPHERE has created and trained a network of resource agents

More information

Science 1206 Unit 2: Weather Dynamics Worksheet 11: Seasons and the Angle of the Sun

Science 1206 Unit 2: Weather Dynamics Worksheet 11: Seasons and the Angle of the Sun Science 1206 Unit 2: Weather Dynamics Worksheet 11: Seasons and the Angle of the Sun Much of the Earth s weather, especially our changing seasons are caused by: 1) Tilt of the Earth - Earth is tilted at

More information

1 Astronomical Coordinate Systems... Continued

1 Astronomical Coordinate Systems... Continued General Astronomy (29:61) Fall 2012 Lecture 4 Notes, August 27, 2012 1 Astronomical Coordinate Systems... Continued 1.1 The Equatorial Coordinate System The most basic astronomical observation is that

More information

Applied Geomorphology. Lecture 4: Total Station & GPS Survey Methods

Applied Geomorphology. Lecture 4: Total Station & GPS Survey Methods Applied Geomorphology Lecture 4: Total Station & GPS Survey Methods Total Station Electronic version of Alidade Accurate to ±3 ppm horizontal & vertical 3x10-6 (5000 feet) = 0.2 inches Total Station Advantages

More information

The diagram shows the apparent paths of the Sun in relation to a house in the northeastern United States on June 21 and December 21.

The diagram shows the apparent paths of the Sun in relation to a house in the northeastern United States on June 21 and December 21. Teacher: Mr. gerraputa Print Close Name: 1. Approximately how many hours of daylight are received at the North Pole on June 21? 1. 0 3. 18 2. 12 4. 24 2. The diagram shows the apparent paths of the Sun

More information

163 ANALYSIS OF THE URBAN HEAT ISLAND EFFECT COMPARISON OF GROUND-BASED AND REMOTELY SENSED TEMPERATURE OBSERVATIONS

163 ANALYSIS OF THE URBAN HEAT ISLAND EFFECT COMPARISON OF GROUND-BASED AND REMOTELY SENSED TEMPERATURE OBSERVATIONS ANALYSIS OF THE URBAN HEAT ISLAND EFFECT COMPARISON OF GROUND-BASED AND REMOTELY SENSED TEMPERATURE OBSERVATIONS Rita Pongrácz *, Judit Bartholy, Enikő Lelovics, Zsuzsanna Dezső Eötvös Loránd University,

More information

Estimation of photosynthetically active radiation under cloudy conditions

Estimation of photosynthetically active radiation under cloudy conditions Agricultural and Forest Meteorology 102 (2000) 39 50 Estimation of photosynthetically active radiation under cloudy conditions I. Alados a, F.J. Olmo b, I. Foyo-Moreno b, L. Alados-Arboledas b, a Dpto

More information

We know the shape of the solar spectrum. Let s consider that the earth atmosphere is 8000 km thick.

We know the shape of the solar spectrum. Let s consider that the earth atmosphere is 8000 km thick. We know the shape of the solar spectrum. How is this spectral shape and irradiance of the solar light affected by the earth s atmosphere? Let s consider that the earth atmosphere is 8000 km thick. The

More information

Coverage Characteristics of Earth Satellites

Coverage Characteristics of Earth Satellites Coverage Characteristics of Earth Satellites This document describes two MATLAB scripts that can be used to determine coverage characteristics of single satellites, and Walker and user-defined satellite

More information

SIMPLIFIED PERFORMANCE MODEL FOR HYBRID WIND DIESEL SYSTEMS. J. F. MANWELL, J. G. McGOWAN and U. ABDULWAHID

SIMPLIFIED PERFORMANCE MODEL FOR HYBRID WIND DIESEL SYSTEMS. J. F. MANWELL, J. G. McGOWAN and U. ABDULWAHID SIMPLIFIED PERFORMANCE MODEL FOR HYBRID WIND DIESEL SYSTEMS J. F. MANWELL, J. G. McGOWAN and U. ABDULWAHID Renewable Energy Laboratory Department of Mechanical and Industrial Engineering University of

More information

SOLAR ENERGY How much strikes the earth? How much can my building get? When is it too much?

SOLAR ENERGY How much strikes the earth? How much can my building get? When is it too much? SOLAR ENERGY How much strikes the earth? How much can my building get? When is it too much? The sun: friend of foe? Drawing by Le Corbusier ENGS 44 Sustainable Design Benoit Cushman-Roisin 14 April 2015

More information

CHAPTER 3. The sun and the seasons. Locating the position of the sun

CHAPTER 3. The sun and the seasons. Locating the position of the sun zenith 90 summer solstice 75 equinox 52 winter solstice 29 altitude angles observer Figure 3.1: Solar noon altitude angles for Melbourne SOUTH winter midday shadow WEST summer midday shadow summer EAST

More information

Estimation of Hourly Global Solar Radiation in Egypt Using Mathematical Model

Estimation of Hourly Global Solar Radiation in Egypt Using Mathematical Model Estimation of Hourly Global Solar Radiation in Egypt Using Mathematical Model Taha Ahmed Tawfik Hussein Agricultural Engineering Department, Faculty of Agriculture, Minoufiya University, Shebin El-Kom,

More information

4 The Rhumb Line and the Great Circle in Navigation

4 The Rhumb Line and the Great Circle in Navigation 4 The Rhumb Line and the Great Circle in Navigation 4.1 Details on Great Circles In fig. GN 4.1 two Great Circle/Rhumb Line cases are shown, one in each hemisphere. In each case the shorter distance between

More information

VOLATILITY AND DEVIATION OF DISTRIBUTED SOLAR

VOLATILITY AND DEVIATION OF DISTRIBUTED SOLAR VOLATILITY AND DEVIATION OF DISTRIBUTED SOLAR Andrew Goldstein Yale University 68 High Street New Haven, CT 06511 andrew.goldstein@yale.edu Alexander Thornton Shawn Kerrigan Locus Energy 657 Mission St.

More information

Dynamics of Iain M. Banks Orbitals. Richard Kennaway. 12 October 2005

Dynamics of Iain M. Banks Orbitals. Richard Kennaway. 12 October 2005 Dynamics of Iain M. Banks Orbitals Richard Kennaway 12 October 2005 Note This is a draft in progress, and as such may contain errors. Please do not cite this without permission. 1 The problem An Orbital

More information

MODELING DISTRIBUTION SYSTEM IMPACTS OF SOLAR VARIABILIY AND INTERCONNECTION LOCATION

MODELING DISTRIBUTION SYSTEM IMPACTS OF SOLAR VARIABILIY AND INTERCONNECTION LOCATION MODELING DISTRIBUTION SYSTEM IMPACTS OF SOLAR VARIABILIY AND INTERCONNECTION LOCATION Matthew J. Reno Sandia National Laboratories Georgia Institute of Technology P.O. Box 5800 MS 1033 Albuquerque, NM

More information

Predicting daily incoming solar energy from weather data

Predicting daily incoming solar energy from weather data Predicting daily incoming solar energy from weather data ROMAIN JUBAN, PATRICK QUACH Stanford University - CS229 Machine Learning December 12, 2013 Being able to accurately predict the solar power hitting

More information

The Four Seasons. A Warm Up Exercise. A Warm Up Exercise. A Warm Up Exercise. The Moon s Phases

The Four Seasons. A Warm Up Exercise. A Warm Up Exercise. A Warm Up Exercise. The Moon s Phases The Four Seasons A Warm Up Exercise What fraction of the Moon s surface is illuminated by the Sun (except during a lunar eclipse)? a) Between zero and one-half b) The whole surface c) Always half d) Depends

More information

User Perspectives on Project Feasibility Data

User Perspectives on Project Feasibility Data User Perspectives on Project Feasibility Data Marcel Šúri Tomáš Cebecauer GeoModel Solar s.r.o., Bratislava, Slovakia marcel.suri@geomodel.eu http://geomodelsolar.eu http://solargis.info Solar Resources

More information

Ok, so if the Earth weren't tilted, we'd have a picture like the one shown below: 12 hours of daylight at all latitudes more insolation in the

Ok, so if the Earth weren't tilted, we'd have a picture like the one shown below: 12 hours of daylight at all latitudes more insolation in the Ok, so if the Earth weren't tilted, we'd have a picture like the one shown below: 12 hours of daylight at all latitudes more insolation in the tropics, less at higher latitudes Ok, so if the Earth weren't

More information

Renewable Energy 35 (2010) 780 787. Contents lists available at ScienceDirect. Renewable Energy. journal homepage: www.elsevier.

Renewable Energy 35 (2010) 780 787. Contents lists available at ScienceDirect. Renewable Energy. journal homepage: www.elsevier. Renewable Energy 35 (2010) 780 787 Contents lists available at ScienceDirect Renewable Energy journal homepage: www.elsevier.com/locate/renene A new methodology to optimise solar energy extraction under

More information

The Earth's Orbit and the Reasons for Seasons

The Earth's Orbit and the Reasons for Seasons The Earth's Orbit and the Reasons for Seasons Many of our most interesting astronomical and meteorological phenomena derive from the particular nature of the Earth's orbit. Thus, understanding the size,

More information

PREDICTION OF PHOTOVOLTAIC SYSTEMS PRODUCTION USING WEATHER FORECASTS

PREDICTION OF PHOTOVOLTAIC SYSTEMS PRODUCTION USING WEATHER FORECASTS PREDICTION OF PHOTOVOLTAIC SYSTEMS PRODUCTION USING WEATHER FORECASTS Jure Vetršek* 1 and prof. Sašo Medved 1 1University of Ljubljana, Faculty of Mechanical Engineering, Laboratory for Sustainable Technologies

More information

Arctic Circle (66.5 N)

Arctic Circle (66.5 N) The Sun and Solar Energy The sun is one of the two primary sources of energy on the Earth (stored energy from the molten core being the other). As such, understanding the sun is important to the performance

More information

not to be republished NCERT Do you feel air around you? Do you SOLAR RADIATION, HEAT BALANCE AND TEMPERATURE SOLAR RADIATION

not to be republished NCERT Do you feel air around you? Do you SOLAR RADIATION, HEAT BALANCE AND TEMPERATURE SOLAR RADIATION SOLAR RADIATION, HEAT BALANCE AND TEMPERATURE Do you feel air around you? Do you know that we live at the bottom of a huge pile of air? We inhale and exhale but we feel the air when it is in motion. It

More information

Mission to Mars: Project Based Learning Conditions on Mars Dr. Anthony Petrosino, Department of Curriculum and Instruction, College of Education, University of Texas at Austin Benchmarks content author:

More information

The Centre for Australian Weather and Climate Research. A partnership between CSIRO and the Bureau of Meteorology

The Centre for Australian Weather and Climate Research. A partnership between CSIRO and the Bureau of Meteorology The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology Testing and diagnosing the ability of the Bureau of Meteorology s Numerical Weather Prediction

More information

Lab Activity on the Causes of the Seasons

Lab Activity on the Causes of the Seasons Lab Activity on the Causes of the Seasons 2002 Ann Bykerk-Kauffman, Dept. of Geological and Environmental Sciences, California State University, Chico * Objectives When you have completed this lab you

More information

Solar Heating Basics. 2007 Page 1. a lot on the shape, colour, and texture of the surrounding

Solar Heating Basics. 2007 Page 1. a lot on the shape, colour, and texture of the surrounding 2007 Page 1 Solar Heating Basics Reflected radiation is solar energy received by collectorsfrom adjacent surfaces of the building or ground. It depends a lot on the shape, colour, and texture of the surrounding

More information

EDMONDS COMMUNITY COLLEGE ASTRONOMY 100 Winter Quarter 2007 Sample Test # 1

EDMONDS COMMUNITY COLLEGE ASTRONOMY 100 Winter Quarter 2007 Sample Test # 1 Instructor: L. M. Khandro EDMONDS COMMUNITY COLLEGE ASTRONOMY 100 Winter Quarter 2007 Sample Test # 1 1. An arc second is a measure of a. time interval between oscillations of a standard clock b. time

More information

Sunlight and its Properties Part I. EE 446/646 Y. Baghzouz

Sunlight and its Properties Part I. EE 446/646 Y. Baghzouz Sunlight and its Properties Part I EE 446/646 Y. Baghzouz The Sun a Thermonuclear Furnace The sun is a hot sphere of gas whose internal temperatures reach over 20 million deg. K. Nuclear fusion reaction

More information

Solar Radiation Hand Book (2008)

Solar Radiation Hand Book (2008) Typical Climatic Data for Selected Radiation Stations (The Data Period Covered : 1986-2000) Solar Radiation Hand Book (2008) A joint Project of Solar Energy Centre, MNRE Indian Metrological Department

More information

1. How many days each year does the Sun rise due East and set due West?

1. How many days each year does the Sun rise due East and set due West? Motion of the Sun Student Page Purpose To examine the path of the Sun across the sky at different times of the year from different locations on the Earth, and study its effects at different locations.

More information

Reason for the Seasons Notes

Reason for the Seasons Notes Reason for the Seasons Notes Seasons Vocabulary Seasons - Due to the tilt of earth as it travels around the Sun, we have spring, summer, fall, and winter. Source: http://www.srh.noaa.gov/abq/features/whatcausestheseasons/summersolstice2008.php

More information

Frequency-domain and stochastic model for an articulated wave power device

Frequency-domain and stochastic model for an articulated wave power device Frequency-domain stochastic model for an articulated wave power device J. Cândido P.A.P. Justino Department of Renewable Energies, Instituto Nacional de Engenharia, Tecnologia e Inovação Estrada do Paço

More information

ASTR 693A Coordinate systems

ASTR 693A Coordinate systems ASTR 693A Coordinate systems The following notes contain the essential information you ll need to understand where astronomical sources are in the sky. Further details can be found in Textbook on Spherical

More information

Local Sidereal Time is the hour angle of the First Point of Aries, and is equal to the hour angle plus right ascension of any star.

Local Sidereal Time is the hour angle of the First Point of Aries, and is equal to the hour angle plus right ascension of any star. 1 CHAPTER 7 TIME In this chapter we briefly discuss the several time scales that are in use in astronomy, such as Universal Time, Mean Solar Time, Ephemeris Time, Terrestrial Dynamical Time, and the several

More information

The Reasons for the Seasons

The Reasons for the Seasons Guiding Question: What causes the seasons on Earth? The Reasons for the Seasons Vocabulary astrolabe equinox rotate axis horizon solstice elliptical revolve (orbit) sundial Materials Exploration (per group)

More information

RESULTS FROM A SIMPLE INFRARED CLOUD DETECTOR

RESULTS FROM A SIMPLE INFRARED CLOUD DETECTOR RESULTS FROM A SIMPLE INFRARED CLOUD DETECTOR A. Maghrabi 1 and R. Clay 2 1 Institute of Astronomical and Geophysical Research, King Abdulaziz City For Science and Technology, P.O. Box 6086 Riyadh 11442,

More information

1. Introduction Measurement of sunshine-duration is one of the oldest solar radiation measurements. Sunshine-duration

1. Introduction Measurement of sunshine-duration is one of the oldest solar radiation measurements. Sunshine-duration December 1986 H. Ikeda, T. Aoshima and Y. Miyake 987 Development of a New Sunshine-Duration Meter By Hiroshi Ikeda, Takeshi Aoshima and Yukiharu Miyake EKO Instruments Trading Co., Ltd. 21-8 Hatagaya 1-chome,

More information

Reasons for the seasons on Earth

Reasons for the seasons on Earth Reasons for the seasons on Earth Background information The Earth orbits the Sun in a slightly elliptical path. This means that sometimes the Earth is slightly closer to the Sun than other times but this

More information

Power Prediction Analysis using Artificial Neural Network in MS Excel

Power Prediction Analysis using Artificial Neural Network in MS Excel Power Prediction Analysis using Artificial Neural Network in MS Excel NURHASHINMAH MAHAMAD, MUHAMAD KAMAL B. MOHAMMED AMIN Electronic System Engineering Department Malaysia Japan International Institute

More information

Seasonal Temperature Variations

Seasonal Temperature Variations Seasonal and Daily Temperatures Fig. 3-CO, p. 54 Seasonal Temperature Variations What causes the seasons What governs the seasons is the amount of solar radiation reaching the ground What two primary factors

More information

Meteorological and weather forecast data-based prediction of electrical power delivery of a photovoltaic panel in a stochastic framework

Meteorological and weather forecast data-based prediction of electrical power delivery of a photovoltaic panel in a stochastic framework Meteorological and weather forecast data-based prediction of electrical power delivery of a photovoltaic panel in a stochastic framework Mario Vašak, Marko Gulin, Josip Čeović, Dražen Nikolić, Tomislav

More information

The Effect of Temperature on the Performance of A Photovoltaic Solar System In Eastern Nigeria

The Effect of Temperature on the Performance of A Photovoltaic Solar System In Eastern Nigeria Research Inventy: International Journal Of Engineering And Science Vol.3, Issue 12(December 2013), PP 10-14 Issn(e): 2278-4721, Issn(p):2319-6483, Www.Researchinventy.Com The Effect of Temperature on the

More information