Is this a good idea for solar tracking system? - Page 1
Forum section: electronics / beginners

author: mohannad
author_rank: Contributor
timestamp: February 27, 2017, 02:37:11 pm
content: I'm trying to make a project for a contest in my country which is limited by the cost and should be innovating.And because we ran out of ideas I thought to make a solar tracker system with a little adjusment.My idea is to make the same independent of sensor lights and continuous movement , but to make it update the module inclination every day / week(saving power) using the actual location of the module on the earth. i.e the user has to provide the module with the longitude and latitude and the module will do the rest.What i want to know is ... Is that a good idea? or .. is that even an idea?Sorry for bad english, it's not my native language.

author: Ian.M
author_rank: Super Contributor
timestamp: February 27, 2017, 03:24:50 pm
content: The Earth's axial tilt is 23.44 deg. Cos(23.44 deg) is 0.9175 so worst case you only loose fractionally over 8% of the effective irradiance twice a year with a fixed elevation panel, with average (over the year) losses of fractionally over 4%. It isn't worth the extra mechanical complexity to add elevation tracking for photovoltaic or solar thermal panels. OTOH if you are driving a large mirror array for a solar furnace, elevation tracking is absolutely critical.As long as the panel is pivoted about an equatorial axis, tracking the sun each day only requires a fixed angular speed drive with provision to reset it to its starting position overnight, however, the mechanical complexity of such a system is considerable, and unless you have sufficient economies of scale that a shaft drive linking multiple panels is practical, its going to be cheaper to use commodity satellite dish actuators with a MCU based controller that is programmed for constant speed motion during the day, reversing to its inital position overnight.

author: mohannad
author_rank: Contributor
timestamp: March 01, 2017, 12:22:57 pm
content: Thanks alot, that helped alot.Do you recommend any resources to go further?

author: Ian.M
author_rank: Super Contributor
timestamp: March 01, 2017, 01:41:38 pm
content: Sorry, cant help you with any resources. The minimum for a constant speed tracker implemented wth a dish actuator would be an H-bridge to drive the actuator, a controller with a RTC, provision to set it correctly, and some means of aligning the panel's rotation axis + setting the initial position to match the current time and setting the limits.Some of the other issues with solar trackers are windage and shading. If a single pivoting mount is used, the stresses on the mechanism rapidly become unsustainable in strong winds as the panel array size is increased. If the array is on separate pivot mounts, it must be fairly widely spaced so that each panel doesn't shade the next one. This increases the cost of the mounts as it is less economic for them to share a common support framework. If the real estate used is more valuable than the actual solar panels, a tracker is not cost effective compared to covering a larger proportion of the available area with fixed panels at the optimum inclination angle.

author: Lightages
author_rank: Unknown
timestamp: March 01, 2017, 02:04:43 pm
content: Solar tracking used to be a worthwhile idea when the prices of panels was much higher. With a fully tracking panel you could gain up to 40% production. Now, it is hardly worth considering. The cost, complexity and maintenance of a tracking system is much more than just adding a few more panels to the system. This is referring to a full 2 axis tracking system that follows the sun exactly all day. The only time a full tracker makes any sense is if there is limited space for panels.A self adjusting daily altitude tracker is definitely a total waste of time. People who want to adjust for sun angle usually have some kind of support that can be adjusted to three different angles and manually adjust the angle every season.

author: ebastler
author_rank: Super Contributor
timestamp: March 01, 2017, 05:48:39 pm
content: Quote from: mohannad on March 01, 2017, 12:22:57 pmIf you ask Google about "solar tracking homebrew" or "solar tracking DIY", you will find quite a few relevant hits.I would assume that amateur astronomers have also come up with interesting solutions, although maybe too precise and too expensive.

author: Seekonk
author_rank: Super Contributor
timestamp: March 01, 2017, 08:37:15 pm
content: Make sure it only operates only once in a while through timing. Continuous operating servo systems can use up more power than gained. It should have some way of moving when the sensor fails, better yet don't use sensor. The planets are predictable.I know, you want to make the most technological device ever. Truth is most solar is over designed for marginal days. Come up with something that will use the energy when the batteries are full, pumping water, heating water distilling water, ventilation. Don't waste energy.

author: ebastler
author_rank: Super Contributor
timestamp: March 01, 2017, 09:21:10 pm
content: Quote from: Seekonk on March 01, 2017, 08:37:15 pmIsn't that exactly what the OP suggested in his initial post?I am not sure whether tracking is needed at all (assuming that this is about a flat panel, not a convex mirror), but if it is required, mohannad's suggested simple approach makes sense to me.