Earth tilt and array alignment

[wattmatters]

Rather than a motorized tracker, I think an array aimed South East and another aimed South West, wired in parallel to the MPPT, is a better way to go.
Extra panels are cheaper than a tracker for the watts they produce.

This.

What is optimal depends on your energy needs. Squeezing out the highest energy production from an array may not be optimal in terms of the complexity and cost of such a system. Panels are pretty cheap and as a result the easiest and most practical answer is usually just adding more panels.

And having a fixed array pointing due South (or North in the Southern hemisphere) and tilted at the angle of latitude will produce the most energy in a given year for a fixed array, but again that configuration may not be optimal especially if peak outputs can't be used or energy supply earlier and/or later in the day is preferred.

Optimal production is production which best suits the use case. For many this means split azimuth arrays, usually with some combination of East, South (or North in the Southern hemisphere) and West facing panels.

Paralleling arrays with different orientations is perfectly fine. You just need to make sure each array in the parallel arrangement is the same size. e.g. I have 2 parallel arrays into one MPPT of my Fronius inverter. One 2.75kW array faces NE, the other 2.75kW array faces NW (I'm Southern hemisphere). Works very well.

 

[robby]

Amazon has a bunch of small hydraulic arms that can move 300lbs using electronic control. Prices vary from $30 to $60 depending on the throw distance.

 

[sarossell]

Thanks for posting this question. I too am interested in the correct azimuth heading to orient my array to. I read most of the replies to your question, but there was a lot of rabbit trails that didn't help. What did you end of setting your array to? I'm getting ready to start erecting the ground mount for my 32 panel array (4 strings of 8 in landscape orientation) this week and need to nail down the orientation as my 10 3" galvanized poles will be set in concrete so when it's done, it's done. Please let me know what you decided. George

Sadly, I placed the panels completely flat on top of mason bricks and then immediately contracted COVID and was sick for 61 days. By then the Arizona Summer was at full pace with daily temperatures well over 110° and I haven't touched them since. At the very least, they should be tilted to allow for water run off when we get the occasional rain out here or when I wash them. As soon as the weather cools down below 100° again (probably mid-September), I'll tackle the problem again.

As they are, I have usable power from 7:30 am to about 5 or 6 pm, barring any cloud cover. The sun is still fairly high in the sky at 5 pm, but the angle and temperature must be a factor. The heat builds like a oven hear so that the "heat of the day" is NOT high noon to 2 pm , but rather 4 pm to 6 pm or until the sun actually sets.

 

[Hedges]

Here's a calculator where you can enter location and panel orientation (e.g. South), then select a tilt (e.g. optimum year round, flat, etc.) and it will give you average effective hours per month.
If you are grid-tie you may want to maximize production over entire year. Off grid with primarily lighting loads, maximize power during winter. For cooling, maximize during summer.

Best azimuth is usually due South (not magnetic, you can look up correction if using a compass), unless you have morning fog or shading. For grid-tie, time of use rates may value afternoon production higher.

Solar Irradiance Calculator

www.solarelectricityhandbook.com

PHX - Phoenix [Phoenix Sky Harbor Intl], AZ, US - Airport - Great Circle Mapper

Airport information about PHX - Phoenix [Phoenix Sky Harbor Intl], AZ, US

www.gcmap.com

"9.98°E (WMM2020 magnetic declination)"

Depending on type of mount, you might implement a manual seasonal tilt. However, PV panels are inexpensive enough that putting up more to make up for off-season is an alternative.
You might use multiple orientations, for lower peak but more hours of production during the day.