Recommended IC for sunlight sensing - Page 1
Forum section: electronics / beginners

author: Craftplorer
author_rank: Contributor
timestamp: December 26, 2016, 11:21:06 pm
content: Hi,can someone recommend me a sensor for sensing sunlight?I want to measure sunlight so i get some data where solar cells are the most effective. The response spectrum of the sensor should be something similar to the spectrum of a solar cell (mono c-Si).I also saw that many sensor ICs contain a "normal" and an IR sensor element and 2 ADCs so i can compensate and adjust the different spectrums of the two sensing elements but i have no idea how.Has someone a link to an artikel or paper on how to calculate this(or can give me a idea where to start)?The IC should be preferable addressable via I2C and measure in a high resolution (>= 16Bit ADC).Please excuse my poor english.Hope someone can help me. Thanks.

author: 2N3055
author_rank: Super Contributor
timestamp: December 26, 2016, 11:45:53 pm
content: Well, how about to just use a small solar cell ?

author: cdev
author_rank: Super Contributor
timestamp: December 26, 2016, 11:54:36 pm
content: If you have the location (latitude) available and know how good the horizon/sky view is throughout the year, (is anything, like a tree or another building, or a mountain, etc, shading it for some of the year/day) and the weather, you should be able to know how cost effective solar is.In some coastal areas, for example, the Bay Area, California in general, and many similar places, because of the coastal fog, or mountains, it likely also varies quite a bit from one microclimate to another.How many days of sun vs. shade.There must be a lot of software programs that do these kinds of calculations out there.

author: Craftplorer
author_rank: Contributor
timestamp: December 27, 2016, 06:42:34 pm
content: Thanks a lot for all the answers.My plan is not to setup any solar cells or produce real power with solar cells. I want to build a solar cell tracker(I think i didnt make that very clear in my first postsorry). But now im thinking do i even need a sensor with a similar spectrum of a solar cell? Or would the difference not noticable and would a simple LDR do the job?Quote from: evb149 on December 27, 2016, 04:05:52 amSeems like they are not i my price range.http://www.eol-shop.com/wind-measurement/sensor-und-accessories/radiation/ISET-Sensor

author: JimRemington
author_rank: Regular Contributor
timestamp: December 27, 2016, 07:14:38 pm
content: You can make a simple solar tracker with a couple of servos, LDRs (light dependent resistors) and an MCU like Arduino.Google "solar tracker ldr servos" or similar for lots of examples. The most difficult task is to come up with a steerable platform.

author: Benta
author_rank: Super Contributor
timestamp: December 27, 2016, 09:26:21 pm
content: First, LDRs are a no-no nowadays, due to Cd content.But if you want to track the position of the sun, visible light sensors are not much help. On a cloudy day, the brightness of the sky is to a large extent uniform.A better approach would be to measure IR radiation from the sky, which would give you an idea of where the sun is. But you'll need to go to IR-wavelengths of ~10 um. Normal IR photodiodes (840...950 nm) will not work.

author: SeanB
author_rank: Super Contributor
timestamp: December 28, 2016, 02:08:24 pm
content: Use a mask and 2 or more phototransistors, so that you can have a sensor to detect dark, and then run the motors to rotate so that each sensor by the mask is getting light equally. For moving a solar panel slow is better, and you do not really need great pointing precision, just more or less normal to the sun, and there you can get away with a simpler single axis mount as well, no need for tracking in 2 axes, just point the panels more or less at the sun to flatten the generation curve.

author: Rolo
author_rank: Regular Contributor
timestamp: December 28, 2016, 06:02:43 pm
content: You can take a look at the TSL2561, it has two sensors and the data sheet gives info about how to calculate with the two values. Also lot's of sample code and library's to be found.

author: Audioguru
author_rank: Super Contributor
timestamp: December 28, 2016, 11:04:37 pm
content: Get a high quality solar panel with a glass top. Some of my cheap Chinese solar garden lights have a solar panel with a plastic top that gets sunburned (no kidding) in a few months.Also seal the solar panel so that rain cannot corrode its back.

author: mtdoc
author_rank: Super Contributor
timestamp: December 28, 2016, 11:49:18 pm
content: Quote from: cdev on December 26, 2016, 11:54:36 pmThe traditional professional tool for solar site analysis is theSolar Pathfinder.A cheaper alternative is a phone app such asSun Scout.

author: jdraughn
author_rank: Regular Contributor
timestamp: December 30, 2016, 12:35:43 pm
content: You can also use GPS to calculate exactly where the sun by taking into account latitude, longitude and time.

author: Jeroen3
author_rank: Super Contributor
timestamp: December 30, 2016, 01:12:44 pm
content: Can't you use known climat data. Such as solargis does?