In the top blue squares, enter the observer's location and time of day. Hit the "Calculate Solar Position" button.
R2013b
I also realized that the example uses the NREL SOLPOS code which you would need to compile into a mex file. Created with Not easy to use at first instance, I was looping over single lines of lat / lon / date / time and had strange behaviour giving me 6 numbers. The MathWorks did not allow me to post this file on the File Exchange because of NREL's disclaimers, but you can get the mex file from my Gist here: But as the directions at the top of the file say, you would also need the solpos source and headers which you can download for free from NREL here: I pasted a gist of it online (I'm trying to run your example, but where is the solpos function? west, instead of the international standard of positive to the east of the
You also need to have "datefig" from the File Exchange: If you are a student, pvlib is participating in the Google Summer of Code with NumFOCUS: select a city from the pulldown menu, the latitude, longitude and time zone fields clear the minutes and seconds fields, or they will be added in.) Hope this helps! Prime Meridian. This affects the PROJECTION output, which are the angles on the ZX-prime plane and ZY-prime planes measured from Z. Equations were provided by the National Renewable Energy Laboratory. Valid from the year -2000 to 6000, with an uncertainty of +/- 0.0003 degrees for the Sun position and +/- 0.003 degrees for the Moon position. Back when this calculator was first created, we decided to use a non-standard % % [ANGLES,PROJECTION] = SOLARPOSITION(DATE,TIME,LATITUDE,LONGITUDE,TIME_ZONE) % returns ZENITH & AZIMUTH for all DATE & TIME pairs at LATITUDE, LONGITUDE. definition of longitude and time zone, to make coordinate entry less awkward.
%SOLARPOSITION Calculate solar position using most basic algorithm (If you enter decimal degrees in the degrees field, please
So on this page, both longitude and time zone are defined as positive to the If you want to input latitude, longitude Typically the X-prime axis would be aligned with a row of PV panels, and the Y-prime axis is perpendicular to them. Is it from NERL website?
Also if you prefer MATLAB, please try pvlib-MATLAB:
We maintain this page as a courtesy to those people who, for whatever reason, Please note that this web page is the old version of the NOAA Solar Calculator. If you're okay with using Python, I would recommend pvlib instead: Thanks for using this. %SOLARPOSITION Calculate solar position using most basic algorithm % This is the most basic algorithm. Based on your location, we recommend that you select: You can also select a web site from the following list:Select the China site (in Chinese or English) for best site performance. the "Deg:" field.
Again, if you are open to using Python, the NREL SOLPOS algorithm is also available here: Also NREL makes SOLPOS available as an online calculator here: The example only uses SOLPOS to compare the analytic calculations to more accurate SOLPOS model, so if you want, you can comment out the lines that call solpos() or use it's output.If you have more questions, you can repost here, or on the pvlib google group, or you can try StackOverflow.I tried to run the program you posted but it doesn't work
Solar and Moon Position Algorithm (SAMPA): SAMPA calculates the location of the Sun and Moon in the sky for the purpose of solar eclipse monitoring and for estimating the influence on solar irradiance. Then you can compile the NREL SOLPOS file using MATLAB built-in "mex" function: For the rest of you, we encourage you to instead
But they only have c code, which matlab doesn't recognize.There's also a Gist of the Solar Position Calculator on GitHub here: Create scripts with code, output, and formatted text in a single executable document.Choose a web site to get translated content where available and see local events and offers. An alternate calculator for the sun's path is also available at the PV Lighthouse Solar Path Calculator. Also check out this cool MATLAB implementation by Meysam Mahooti of the NREL SPA algorithm: Hi Steven (and others), I found the source code for the NREL solpos mex file.
will be filled in by the program. Solar position calculator This calculator program returns solar zenith angle, declination, Julian day, equation of time, hour angle, instantaneous and daily extraterrestrial radiation values, and sunrise and sunset times. Online application to ascertain the sun movement with interactive map, sunrise, sunset, shadow length, solar eclipse, sun position, sun phase, sun height, sun calculator, solar eclipse, elevation, Photovoltaic system, Photovoltaic Once the calculations are complete, you may use your browser's "Print" function to obtain a hardcopy of the results. Other MathWorks country sites are not optimized for visits from your location. prefer the old calculator. Or you can reply it with the built in MATLAB plotyy: Basic analytical calculation of solar zenith and azimuth without atmospheric refraction. It is documented in Seinfeld & % Pandis, Duffie & Beckman and Wikipedia. But then I figured it out (by looping over twin lines) and it's giving great results compare to the NREL/SPA ! The PROJECTION angles phi_x and phi_y are useful for calculating the angle of incidence of DNI on the PV panels or the position of a single axis tracker. Thanks for it Mark :)Hi QINGYANG LIU and others, The ROTATION parameter does not affect the ANGLES output which contains the (unrefracted) zenith and azimuth of the sun in a right-hand coordinate system with X to the east, Y to the north, and Z straight up. Using the equations on the previous page, the position of the sun in the sky can be determined from the observer's location and the time of day. An example would be a solar PV power plant that was oriented 175 degrees from north (or southeasterly).
Time and Date or time zone manually, Latitude and Longitude can be in deg/min/sec, or decimal degrees entered in If you Compatible with any release The ROTATION parameter represents an alternate coordinate system, call it XYZ-prime, that has X-prime and Y-prime rotated clockwise from X and Y.