Solar tracking technology borrows from plants to point PV at the sun

This article speaks of a solution developed by students at MIT that allows a solar PV panel to follow the sun using a method that mimics how plants turn their leaves to get the best exposure.

Wade
(Nov 30, 2010)

Boston (MA) - Students at MIT participating in the annual MADMEC (Making And Designing Materials Engineering Contest) have devised a zero-input energy solution which allows solar panel arrays to track the sun's movement thereby increasing solar panel efficiency by 38% over stationary panels. The three-person team of Forrest Liau, Vyom Sharma, Geroge Whitfield, all Materials Science graduate students, won top honors and a $10,000 prize for their invention.

Borrowing from the very technology used to track the sun by plants coupled to the relatively primitive approach used in coil-based temperature gauges, the device is basically a temperature sensor that responds mechanically to changes in heat. Constructed from bimetal aluminum and steel, two materials which expand at different rates when exposed to identical changes in temperature, the device is built into a type of arch affixed permanently at one side and attached to a pivot arm on the other.  As the sun moves it heats up different portions along the arch causing it to flex and bend to varying extents allowing the solar panel to track with the sun's movement, as per the expansion of the arch.

The team is exploring additional methods and materials for creating zero-energy tracking systems, ones that will continuously orient the solar panel at a more accurate perpendicular and planar angle to the sun.  The idea of having completely autonomous solar panel tracking mechanisms is very exciting, especially in developing nations where an additional 38% efficiency would be most desirable.

Solar panels that orient themselves are so much more efficient than stationary models, albeit more costly, that the extra energy they generate more than makes up for the small amount of energy required to track the sun through movement by electric motors and tiny computers which compute the angle at various points throughout the day.  This team's solution will simply do the same job less costly and without parts which will more easily wear out over time.





"MIT develops solar panels which track the sun without motors,"
TGdaily(2010), Rick C, Hodgin, Mon 22nd Sep 2008, 08:35 am.
Accessed November 20, 2010, http://www.tgdaily.com/trendwatch-features/39411-mit-develops-solar-panels-which-track-the-sun-without-motors .