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Single-axis solar tracker profit analysis

The questions are: What is a single-axis solar tracker? Is it worth the investment? I will make a small comparative analysis using the SPAC application. I will take 4 randomly selected cities on 4 continents in the Northern Hemisphere. North America’s Philadelphia, cloudy Manchester in Europe, Port Sudan in North Africa’s and Asia’s Kabul, Afghanistan. The SPAC  application  considers not only latitude but also climate statistics (the Solar insolation of selected regions).

What is a single-axis solar tracker?

Single axis solar tracker is a mechanical system that serves to rotate the solar panels around one axis in order to achieve the most favorable angle in order to maximize the use of the solar rays that fall on them. Let’s not forget this angle: the incident angle should be as close as possible to 0 (cos(0) = 1).

Of course, in order to achieve this condition, it is necessary to rotate the solar panels in two axes (dual axis tracker), but that system is a bit more complicated and is discussed in another text.


Division of single axis trackers by axis geometry

The solar panels in the single-axis system rotate around an axis that can be

1) vertical in relation to the ground

2) horizontal (parallel to the ground)

3) at an angle to the ground

Vertical axis

The solar panels rotate to follow the sun from east to west during the day. The tilt angle is constant.

Horizontal axis

The solar panels are rotated so that their tilt angle changes. They are fixed or much as possible towards the south. The tilt angle is going to change every month.

This type of tracking system is the subject of further analysis.

Axis at an angle to the ground

This system rotates around an axis that is at an angle to the ground. That axis projection is usually the north-south direction line.

This system is closest to the dual axis tracking system, and more will be said about it in another post.

Division according to the mode of operation

In order to rotate the panels, it is necessary to invest in mechanical work. That work can be

a) manual drive

b) mechanical drive

Mechanical drive implies the use of power transmission (gears, hydraulics, pneumatic, etc.).

A manual drive is cheaper, does not require the above-mentioned assemblies, and you can make it yourself.

Manual drive

I assume you are all familiar with the concept of manual panel angle adjustment.

Of course, nothing has to be done with raw power; mechanical aids can and should be used to adjust the angles of the PV module setting.

The tilt angle needs to be adjusted once a month, 12 adjustments a year, and that’s it.

The simplest system is the bed layout, similar to adjusting the inclination of a deckchair on the beach (horizontal axis).

We will use the SPAC application for a short analysis of energy gain.

One axis simple bed layout monthly adjustments
Horizontal bar with holes for monthly adjustments

Profit analysis

In the next analysis, the following data will be set for all cities: 1. A fixed panel placed to the south at an ideal angle (which we also get with the help of the SPAC application). The axis of rotation is horizontal. 2. South-facing panel setting and monthly tilt angle adjustment 3, Two axis tracker The number of panels for all examples should be nine (3×3 in a row). The first one in the database is Aptos DNA 108, with a power of 390 kW. We will use three calculation options for each city: fixed, one axis tracker, and two axis trackers.
First, we enter the data for Philadelphia the optimal angle for the fixed panel is approximately equal to the latitude.
Mode Power[kWh] Gain
fixed 4562
one axis 4851 6.33 %
two axis 6302 38.14 %
Let’s go to Euroer and see what the situation is in cloudy Manchester in UK.
Mode Power[kWh] Gain
fixed 2330
one axis 2446 4.98 %
two axis 3256 39.74 %
And now we are going to North Africa;
Port Sudan is the next destination, a city in the Sahara.
Mode Power[kWh] Gain
fixed 6374
one axis 6759 6.2 %
two axis 8778 37.72 %
and finally in Asia, let’s consider Kabul , a city where it doesn’t often rain.
Mode Power[kWh] Gain
fixed 5963
one axis 6350 6.49 %
two axis 8232 38.05 %
All parameters set for analyses
axis analyse results
The results and chart


Is the single-axis bed layout worth the investment for a gain of only 6%? I think it is for a larger number of panels that can be easily adjusted monthly.

For example, if we had a mini-power plant with 90 panels and assumed an electricity price of 0.15 USD/kWh, the annual profit would increase by 170 USD.

For a smaller number of panels or panels placed on the roof at an angle, for cloudy areas it is unsuitable to use this system.

Miroslav Mitić

Mechanical engineer and programmer for 25 years. Solar energy expert

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