You don't want to read the whole thing

REI Tracker

Let's summarize at the beginning; Tracker loadable up to 15 units in a standard size (1.7m x 1m) with an optical driver is the optimal solution for household. The current power of the panels give up to 6kWp of power available on one set. So we get about 9MWh / year on each tracker.

Tracker purchase cost (NET);

up to 15 photovoltaic panels

  • (base) System elements + executive drawings:
    ~ 1200 USD
  • (opti) Set without work surface + drawings:
    ~ 1600 USD
  • (full) Set with work surface:
    ~ 2200 USD

excluding transport costs Differs much.

technical review

smart solar tracker

Smart Solar Tracker is designed to maintain angle in a horizontal and vertical position of mounted on it device/collector. In our case the Smart Tracker was used for appropriate alignment of tilt, pan, roll angles of photovoltaic panels corresponding to geographical location in relation to the changing position of the sun, in a way, so that sun rays fall on modules fixed on the panel, at an optimal angle to reach the possibly longest time period of maximal power production over every day in the year.

This solution greatly improves efficiency of photovoltaic modules. Measurements taken at an altitude of 51 °N, indicate that energetic efficiency of photovoltaic panels fixed on our rack, over the whole year, increased by 40% in comparison to modules with the same power, fixed on a roof surface in a standard way with direction of 0 °S and tilted at a 35° angle.

Such increment of efficiency allows to greatly limit cost of investments and save space that is necessary to achieve assumed efficiency of the whole installation. Introducing an inexpensive and easy in maintenance and repair design is a condition to achieve this goal.

Well known solutions

In the current market there are solutions which allow to modify the position of photovoltaic panels in one or two planes. However, available constructions are designed to handle too small number of panels on a single rack, to make the purchase of such system to be economically reasonable. The reason of limiting the size of the panel surface is inability to expose as-is design to unfavorable atmospheric conditions, e.g. wind force. Suggested rack designs, e.g. of a column type, absorb essential amount of produced energy to position the panels, especially when we deal with the influence of air masses.

So far, producers use centrally positioned column, in order to apply central mounting of a bearing what results in a lack of possibility to use a drive mechanism other than the one based on a toothed rim. Column based solutions cause an increase of rack production and raise the cost of the whole system.

technical disadvantages

Some devices that may be found in the market, allow for installation of the larger number of modules, however, they are costly in production because of an expensive method of bearing mounting and an expensive drive for the column structure. Large non-modular elements, force the need for special type of transport and specialised tools and competences for installation. That results in inadequate design-related costs. Such approach of create an extensive farms which have relatively poor return rate of the investment.

Central column alternative

After the analysis of market possibilities we decided
to design from scratch two kinds of solutions, whit most important features:

  • Modular installation system, that allows to use decentralized process of production - also in facilities with a low availability of technology. Further enables to maintain an optimal business model and supply chain.
  • Inexpensive, dedicated drive system of a high precision. Regardless of the type of used motors (step motors, BDC, DC), it is able to provide continuous tracking of the sun using the same electronics.
  • The solution that provides as well wide scope of adaptation as low susceptibility to interference. Flexibility in anchoring the structure to the ground. Possibility to install the device on poles driven into the ground.
  • Possibility to install the system on top of the flat roofing or gable roofing

Smart Tracker approach

Because economically optimal diameter of the system should be equal to a minimum of 1.5m in radius, the Smart Tracker guide has to have a modular structure, which allows to achieve this assumption without logistic constraints which appear in solid elements. Relatively large diameter of the guide in relation to the height of the rack allowed to acquire three very important and unavailable for other designs, features:

  • Low energetic requirements of the electric motor designed for the drive system responsible for positioning the set in the directions: east – west. It was also possible to apply a small stepper motors in order to increase the precision of rotary movement - The motion of the set which follows the sun position, means a turn of about 0.25 degree per one minute in dependence on a time of the day and year.
  • Simplified structure of mechanical gears, translates into lower energetic losses of the drive. With so large diameter of the set, the system is able to obtain much larger torques, what further enables the usage of a smaller and less expensive worm drive, whit self-braking stability to provide the rack positioning, even when the power supply of the motor is set off.
  • Increased stiffness of the system, based on features of the frame construction and obtaining larger spaces between support points of the main frame, therefore also the upper frame. It minimizes the risk caused by gusty winds which accompany increasingly intensified climatic anomalies.
  • Option to install the rack on a gable and flat roofing structures. The construction itself is balanced enough so that anchoring is treated as a security element and not required.
  • Opportunity to eliminate expensive foundations, requiring documentations and also official construction notification in favor of the ballast or screw-in ground anchors. The process significantly decreases the cost of large installations, it is possible to be done with usage of automated equipment. Insignificant environment influence – the anchors may be dismounted with usage of the same machine. In case of small installations the ballasts enable to make the construction mobile. - to use it as power source in places without a power form grid.

Increased stiffness of the design and frame based structure also enabled to eliminate a weak point of the construction which resulted from imperfections of market available drives designed to tilt the working plane. Engineers commonly use linear motors based on a trapezoidal screw. With mounting as shown on the exemplary figure;

wind load graph

Because the mounting of the linear actuator on a pole structure has to be done in a way that enables the movement of the mounting together with the upper frame, the size of the actuator and its parameters must be significantly limited. The weakness of this solution manifests with a low resistance to a jerk of waving plane working on the wind. The wavy motions are a result of combination of dynamic force of the wind and gravity. The size of the working plane increases the torque that is transferred by the constructions to the linear actuator.

deformations on working plane one and two-column stand exposed to the wind

Usage of the dedicated slide drive enables to acquire a beneficial stiffness of the structure, and in addition, in the moment of adjusting working plane to the horizontal secure position (similar to the parallel position towards the earth), it greatly increases the resistance of the system on influence of strong and gusty winds. Most of the controllers available in the market, after connecting a wind gauge, enable to set the rack in a default and safe position in case of detection of threshold speed of the wind. Default position in actual working conditions is not always optimal because of the terrain shape.

the default safe position of the working plane in real field conditions

Our dedicated slide drive also plays a reinforcing role for the main frame, because its guide is integrated with the elements of the whole framing by skeletal structure.

reliable dedicated slide system


Smart Solar Driver

For micro-installations

Standard solar tracker

The standard solar tracker has been designed so that everyone is able to assemble and run the device. What's more, you can make a work surface for 12, 15 or 18 photovoltaic panels up to 1.7 m high. This means that in today's conditions you can safely get 6kWp power on one tracker, receiving up to 9MWh per year. The set (without work surface) can arrive on a EUR pallet. The work surface itself can be made entirely of steel metallurgy available in stocks without welding.

The base requires pouring the ring, which can be placed directly on the ground (without excavation) or using the ground as a formwork. The height of the ring is about 35-40 cm. Both "wet" and "dry" concrete can be used for pouring such a base. only 1m3 of concrete is needed. No special reinforcement is required, 2 wires ø6 mm are enough to connect the legs in the concrete. (pass through the holes in the legs).

Some also place the structure on posts, sometimes it makes sense when the ground is extremely steep. The structure itself is balanced with the panels so that the profile only provides the stability of the base and no additional weight is required on the base. Spread footing.

You don't have to buy the whole set. If you have a workshop with basic equipment, an angle grinder or a drill and a few wrenches are enough, you can get system elements from us and the drawings and bill of materials needed to make the remaining elements. This way you will save a lot on the entire installation. The work surface and the panels themselves are very easy to install. The working surface consists of profiles up to 6m long, so you pay mainly for transport, not the product itself.

Tracker purchase cost (NET);

up to 15 photovoltaic panels

  • (base) System elements + executive drawings:
    ~ 1200 USD
  • (opti) Set without work surface + drawings:
    ~ 1600 USD
  • (full) Set with work surface:
    ~ 2200 USD

excluding transport costs Differs much.

What's in each set

Smart solar tracker

  • (base)Optical controller (electronic system with the necessary peripherals)
  • (base)Galvanization on all delivered structural elements.
  • (base)Profiles bent and welded (guide for the rotation drive) and anchoring for pouring in concrete (legs).
  • (base)Roller sets adapted to the guide and assembly elements for rollers.
  • (base)Gears, motors, chains and assembly elements.
  • (base)Tilt drive guide with a complete drive.
  • (opti)Elements of the main frame structure and lashings.
  • (full)The working surface is adjusted to the photovoltaic panels selected by the customer, together with the anchoring of the panels.