Energy News Monitoring

In continuation of the previous article dated 08.09.2022, dedicated to patent analysis of inventions related to the floating solar panels with tracking system, below we provide a brief analysis of inventions related to single-axis trackers for your consideration.

Almost 1800 patent documents published in the twenty-year period from 2002 to 2021 were selected for the analysis by using Advanced Energy Technologies methodology.

The collected documents were published in 42 patent offices of the world by 811 applicants from 31 countries.


Solar energy. Single-axis trackers. Relationship of number of applications to total number of documents by year



Based on the chart above, we can see that although there was a moderate decline, the number of patent application filed during the recent years was still substantial. In 2018-2020 about 40%-50% of the technical solutions were represented by start patent applications, that didn’t belong to previously formed patent families. Also, the emergence of a large number of new patent offices and new IPC subgroups, and a moderate number of new applicants involved in this field of technology, can indicate that this subject is still under development and that the authors of the inventions are willing to extend geographical and technical coverage of the technology.

The largest number of patents were granted in USPTO (US) during the twenty-year period – almost 25% of the entire collection of patents. It was closely followed by CNIPA (CN) with about 24%. CNIPA (CN) was leading with a share exceeding 30% by the number of patent applications registered in the past 5 years. KIPO (KR), EPO, OEPM (ES), and IP Australia (AU) should also be mentioned as the patent offices that granted more than 20 patents each on the subject of interest during 2002-2021.

Solar energy. Single-axis trackers. Breakdown of inventions by patent offices. Patents, 2002-2021 (left); Applications, 2017-2021 (right)



The USA was the leader by the number of registered documents in both the case of patents published in the 20-year period, and in the case of recent applications published in the past 5 years. In both cases residents of the USA comprised 29%-31% of all applicants participating in the patenting process. High activity was also shown by residents of China, France, Spain, South Korea, and Germany.

Below is a list of top 10 leading applicants for patents published in the 20-year period:

Solar energy. Single-axis trackers. Top applicants. Patents, 2002-2021

In the collection of patents published between 2002-2021, SunPower Corporation (US) was leading in terms of Market involvement ratio (Market involvement ratio = volume ratio multiplied by ownership ratio, where Volume ratio - share of applicant documents in total number of documents, Ownership ratio - applicant's participation share in total number of documents) with a value exceeding 6%. It was followed by NEXTracker Inc. (US) and Exosun (FR) with more than 2% each. NEXTracker Inc. (US) and Optimum Tracker (FR) were in the lead here in the case of applications published in the past five years.

Solar energy. Single-axis trackers. Top applicants. Applications, 2017-2021

Among the patents and patent applications describing technologies of solar tracking for single-axis installations, the most commonly mentioned problems were Low efficiency due to solar movement, High costs of equipment production, and High costs of repair and replacement. In the vast majority of cases, both patents and patent applications were presented in the form of devices. Methods can be encountered substantially less often, while compositions were not met at all. In the collection of patents and patent applications collected for the present analysis, the most popular IPC subgroups were H02S20/32 (Supporting structures being movable or adjustable, e.g. for angle adjustment... specially adapted for solar tracking), F24J2/54 (Arrangement of mountings or supports ...specially adapted for rotary movement), F24J2/38 (Use of solar heat, e.g. solar heat collectors ...employing tracking means), F24S50/20 (Arrangements for controlling solar heat collectors ...for tracking), and H01L31/042 (PV modules or arrays of single PV cells).

A strong growth in the number of patents describing arrangements for tracking in solar heat collectors (F24S50/20) is shown in the last three years of the 20-year period. In recent applications published in the past 5 years, this technical aspect also demonstrates high values, with a peak in 2019.

In the field of photovoltaics, supporting structures directly fixed to the ground (H02S20/10) appear in the collection of patents mainly starting with 2016 with a peak value in 2020. In recent applications, the largest number of documents disclosing such technical solutions was registered in 2019, and in general they demonstrate a slight growth trend.

The three largest patent families of the entire collection of documents made for the present analysis each include 21 patent documents and are represented by core documents AU2013200320A1, US20150168019A1, and WO2015126890A1 (Core document is a base document for which a complete description of the invention is available in generally-accessible patent databases):

AUTOMATIC SOLAR TRACKING ADJUSTMENT/CONTROL APPARATUS OF SOLAR GENERATION SYSTEM / A: AU2013200320A1 / IPC: F24J2/38, F24J2/54 / Luo Chia Ching / BIG SUN ENERGY TECHNOLOGY INCORPORATION, LUO CHIA CHING / Appl. date: 22/01/2013; Publ. date: 07/11/2013 / IP Australia / Core document: AU2013200320A1 / Technology categories: G / Technology elements: TR, Tms, Tsa, Tsp, Tss / Problems: LESM / Technical solution types: D / Claims: 21 / Rating: 11

SOLAR TRACKING CONCENTRATOR / A: US20150168019A1 / IPC: F24J2/38 / Kim Byunggyun / Kim Byunggyun / Appl. date: 09/01/2014; Publ. date: 18/06/2015 / United States Patent and Trademark Office / Core document: US20150168019A1 / Technology categories: PT / Technology elements: TR, Tcc, Tsa, Tsp, Tss / Problems: LESM / Technical solution types: D / Claims: 2 / Rating: 9

TORSION LIMITER DEVICES, SYSTEMS AND METHODS AND SOLAR TRACKERS INCORPORATING TORSION LIMITERS / A: WO2015126890A1 / IPC: F24J2/38 / CORIO Ronald P / CORIO Ronald P / Appl. date: 18/02/2015; Publ. date: 27/08/2015 / World Intellectual Property Organization / Core document: WO2015126890A1 / Technology categories: G / Technology elements: TR, Tda, Tfp, Tms, Tsa, Tsp / Problems: HCEP, LEEF / Technical solution types: D, M / Claims: 19 / Rating: 9

Below are several examples of patent documents having the highest rating calculated using Advanced Energy Technologies methodology, from the pool of documents describing single-axis solar trackers:

Solar energy. Single-axis trackers. Prominent patent documents by rating, 2002-2021:

Entrainement de suiveur solaire (en: Solar tracker drive) / P: MA34337B1 / IPC: F24J2/38, F24J2/54, F24J2/40 / Almy Charles, Barton Nicholas / Sunpower Corporation / Appl. date: 25/12/2012; Publ. date: 01/06/2013 / Moroccan Industrial and Commercial Property Office / Core document: MA34337B1 / Technology categories: CPV / Technology elements: TR, Tcc, Tda, Tfp, Tms, Tsa, Tss / Problems: HCEP, LESM / Technical solution types: D, M / Claims: 20 / Rating: 21

Tracking solar collector assembly / P: US7888588B2 / IPC: E04B7/02, H02N6/00, H01L25/00 / Shingleton Jefferson G / SunPower Corporation, Systems / Appl. date: 27/05/2009; Publ. date: 15/02/2011 / United States Patent and Trademark Office / Core document: US7888588B2 / Technology categories: G / Technology elements: TR, Tfp, Tms, Tsa, Tsp / Problems: HCRR, LESM / Technical solution types: D / Claims: 20 / Rating: 20

Method for Predictive Control of the Orientation of a Solar Tracker / P: US10903783B2 / IPC: H02S20/32, F24S25/12, F24S50/20, F24S30/425, F24S50/80, F24S50/00, G05B15/02 / Arliaud Jerome, Crucifix Adrien, Blanc Philippe / NEXTracker Inc. / Appl. date: 21/01/2020; Publ. date: 26/01/2021 / United States Patent and Trademark Office / Core document: WO2016193612A1 / Technology categories: G / Technology elements: CS, TR, Tfp, Tsa, Tsp, Tss / Problems: HCRR, LESE, LESM / Technical solution types: D, M / Claims: 17 / Rating: 19

Sun tracking solar power system hardware and method of assembly / P: US9998064B2 / IPC: H02S20/10, H02S20/32, H01L31/052, H01L31/042 / Wares Brian S, Grushkowitz Tyler, McKibben Nicholas / SunPower Corporation / Appl. date: 07/10/2015; Publ. date: 12/06/2018 / United States Patent and Trademark Office / Core document: US20150187975A1 / Technology categories: G / Technology elements: TR, Tcc, Tda, Tfp, Tsa, Tsp / Problems: HCEP, HCM, HCPC / Technical solution types: D / Claims: 20 / Rating: 19

SUN TRACKING SOLAR POWER SYSTEM HARDWARE AND METHOD OF ASSEMBLY / P: US9184324B2 / IPC: H01L31/042, H01L31/052, F24J2/54, F24J2/38 / Wares Brian S, Grushkowitz Tyler, McKibben Nicholas / SUNPOWER CORPORATION / Appl. date: 30/12/2013; Publ. date: 10/11/2015 / United States Patent and Trademark Office / Core document: US20150187975A1 / Technology categories: G / Technology elements: TR, Tcc, Tda, Tfp, Tsa, Tsp / Problems: HCEP, HCM, HCPC / Technical solution types: D / Claims: 19 / Rating: 19

Tracking solar collector assembly / P: US7554030B2 / IPC: E04B7/02, H01L25/00, H02N6/00 / Shingleton Jefferson G / SunPower Corporation, Systems / Appl. date: 16/03/2004; Publ. date: 30/06/2009 / United States Patent and Trademark Office / Core document: US7888588B2 / Technology categories: G / Technology elements: TR, Tfp, Tms, Tsa, Tsp / Problems: HCRR, LESM / Technical solution types: D / Claims: 32 / Rating: 19

Among the patents published over 20 years, there is a pronounced growth in the number of documents related to the problem of High costs of equipment production. However, among recent patent applications, the number of documents addressing this problem has declined in the past two years, after a peak period.

Patents aimed at solving the problem of High costs of repair and replacement show a moderate upward trend. In applications over the past five years, the number of such documents fluctuates at a high level.

At the same time, the number of mentions of Low efficiency due to solar movement in patents granted between 2002 and 2021 began to decline on average after a peak value in 2016, while the number of applications solving this problem was varying in medium-high values.

Below are several examples of patented solutions that to some extent aim at solving the above problems.

- US10697669B2 – a solar position tracker that evaluates camera sensor images of a shadow cast by a shadow blind to increase the efficiency of tracking process;

- US10972044B2 – a reduced cost support structure system of a solar tracker involving specific structural elements, support arches, rolling members, and kinematic drive devices;

- US10684348B2 – a method of controlling solar trackers involving observing cloud coverage, comparing it with pre-set coverage models and setting corresponding setpoint values. The method allows to take into account the wear of equipment in the tracking process;

- US10333458B2 – support assembly of a solar tracker comprising drive motors, modular torque tube, non-driven supports with bearings, characterized in improved robustness

Low efficiency due to solar movement

Patent US10697669B2 by Erfis Gmbh (DE) discloses a concentrated solar power system comprising a solar position tracker able to detect shadow of a shadow blind. As proposed by the authors, the receiver tube of the CSP system is shadow blind, and the system includes a camera positioned between the shadow blind and the shadow receiver and able to detect such shadow to determine its deviation from the target position by using a digital image processing in order to adapt the position of the reflector and receiver. Image taken by the camera is evaluated by decomposing scan lines into black-and-white values with increased contrast, and by determining a shadow entrance, exit and penumbra region. Then shadow center is calculated and compared with the target position to perform correction of the tracking mechanism. The claims of the invention describe the system and method of its operation.

The authors mention tracking accuracy as one of the prior art problems.

The patent document belongs to a family of 14 documents registered with AU, DE, WO, CN, EP, US, CL, MA, TN, and ZA between 2016 and 2020.



Image from: US10697669B2

High costs of equipment production

Patent US10972044B2 by Nexans Solar Tech (FR) discloses a single-axis solar tracking system. The solar tracker according to the invention comprises a mobile device having a table with solar energy collectors, and a support structure supporting the table and comprising a beam in a form of lattice structure. The support structure includes several longitudinal members; a plurality of crossmembers interconnecting the longitudinal members and forming a number of triangles; and a plurality of tie rods interconnecting the triangles. The support structure is positioned on two support arches, which, in turn, are positioned on two ground supports having rolling elements rotatably mounted thereon. The rolling elements are configured to roll on rolling strips of the support arches, thus supporting and guiding them. The tracker also comprises a kinematic drive device including main and complementary transmission members to drive the support arches in rotation relative to the ground supports. Claims of the invention include dimensional specifications of the system’s elements and principles of their interconnection. The authors point out that the costs of the tracker are reduced compared to prior art solutions.

The patent forms a part of a family that includes 20 documents published between 2018 and 2021 in WO, CN, EP, AU, CL, US, and MX.



Image from: US10972044B2

High costs of repair and replacement

Patent US10684348B2 proposed by NEXTracker Inc. (US) describes a method for controlling an orientation of a solar tracker by repetitively completing successive control phases. Each phase includes observing a cloud coverage, comparing it with cloud coverage models associated with orientation setpoint values, matching the observed coverage with a model, and controlling the orientation of the tracker by applying the setpoint value associated to the retained model. The cloud coverage models include zero-cloud coverage models, where the setpoint value corresponds to a direct inclination angle based on an astronomical position of the Sun; and widespread cloud coverage models, where the orientation setpoint value corresponds to an angle of horizontal setting of the tracker. An individual orientation setpoint value is assigned to each cloud coverage model, depending on the cloud layer. The setpoint value in each model also considers such aspects as wear rate, energy consumption, and a displacement speed of the tracker. The claims of the invention include specific models for various cloud coverage conditions and successive steps of servo-controlling the tracker based on provided algorithms.

The patent is a part of a patent family comprising 15 patent documents published in CN, EP, FR, WO, BR, and US in 2017-2021.



Image from: US10684348B2

US10333458B2 patented by SunPower Corporation (US) describes a solar-tracking system comprising several driven support assemblies with two motor drives mounted on respective piles, a torque tube coupled to the first and second motor drives on each side, a controller electrically connected to and independently controlling the motor drives to rotate the torque tube and track the sun. The motor drives are equipped with worm gears to input torques to the ends of the torque tube. Non-driven bearing-equipped support assemblies are positioned between the driven assemblies of the tracking system. The torque tube is made of a number of sections with a length less than 40 feet and extends through the bearings of the non-driven support assemblies. The sections are connected by joints with a torque tube coupler having a closed wall section. In the description of the invention the authors mention stiffness and robustness of the torque assembly as one of the problems with existing solar trackers, which may imply longer operating life of the trackers.

The document belongs to a family including 4 patent documents published between 2018 and 2021 in US and CN patent offices.



Image from: US10333458B2

More detailed information about inventions in the field of solar trackers, and patent research methodology can be found on aenert.com and in SOLAR ENERGY. Solar Trackers. Extended patent report. June 2022.