Energy Matters Forums

[Gordon-Loomberah]

I am assuming that you mean 2-axis tracking, such that I could focus on a point in space and track it completely, as distinct to 1-axis tracking (vertical) and 1-Axis (vertical) adjustable.. as is being highlighted by the discussion.

I didn't read the whole article, so dont know exactly what the author means by 2-axis trackers. There are several types available, some altitude-azimuth (alt-az) mounts (which is the next tracker building project I've started on) are the correct 2 axes, and are used on some telescopes,military guns etc. Others adjust the tilt of a pseudo-equatorial axis, and are the wrong 2 axes to track in, as they only roughly approximate pointing at the sun, and can be way off in morning and evening at higher latitudes.

Gordon - do you have a Mathematical feeling for the difference a 1-Axis (vertical) tracker would make...
I have often thought how easy it would be to make infinitely adjustable struts..

I suspect you mean adjustable tilt, rather than adjustable tracking (which involves rotation)? Any method of moving the panels that keeps them pointed within about 10degrees of the sun will get close to 100% of the available energy, thats why they only need adjusting a few times per year. Adjustable tilt is only going to maximise that when the tilt is in the direction of the sun though. Laying the panels flatter in summer is a help, because panels tilted for winter will have the sun behind them for some time in early morning or late afternoon, more so at higher latitudes.

ie - if the author is correct and the advamtage of FIXED over ADJUSTABLE is only about 4%,

I haven't worked it out, and no time to sit down and do so, but I would guess the difference would amount to more than 4%. What do the online calculators suggest it is?

[mick_queensland]

Hi Tracker and Gordon,

geez I love these theoretical discussions. Sometimes, you can even use the info to optimise a system .

Tracker, I suspect that adjusting the angle of the dangle twice a year will give a measurable increase in output and therefore is worth the effort and small cost for the gains.

As you suggest, making an infinitely adjustable array mount is going to take some money and effort. So it depends on whether you have the time, expertise and material handy to construct such a beast (assuming that buying one is going to be way too expensive for the gain)

One thing to consider also, if you are in a suburban situation with your array mounted on a roof, you will need to consider wind loading if the array is not mounted flat against the roof line. This may add cost including engineering to calculate the required mods to the roof trusses/beams etc. a builder and council approval etc. yikes!

Cheers
Mick