Besides utility managed solar farms, solar developers are targeting other open spaces, such as auto parking lots, for large-scale energy savings (Source: Phys.org)

The surge in these installations is prompting a parallel upswing in solar infrastructure, which is seeing its own technology advances as a result of high demand and the need for greater cost efficiencies. While sturdy racking is important to protect against the ravages of nature, one of the main requirements for large solar farms — and any larger installation — is solar tracking equipment.

Solar tracking offers grid operators the opportunity to squeeze efficiency from sunlight at all hours of the day. While fixed-panel arrays are highly efficient for general-purpose energy harvesting, single-axis solar tracking can increase a solar farm’s annual output by roughly 30 percent. Dual axis trackers can add 10-20 percent beyond that. For example, air mass tables for solar panels show that a panel mounted on a tracker can harness as much as 60% of solar intensity in the late afternoon at an angle of 15 degrees, 50% at 10 degrees, and capture 25% at a mere five degrees. In large installations these gains can mean the ability to respond with enough power to satisfy peak demand.

Solar tracking systems explained

A solar tracking system is used for a variety of applications. Depending on the applications, the mounting systems will differ somewhat. Typically solar trackers hold single or multiple standard flat panels, arranged in rows and funneling power to an energy storage site or directly to a substation.

Parabolic mirrors can focus sunlight onto solar collectors. (Source: EU Solaris)

However, solar trackers are critical for large-scale solar installations using concentrated solar power (CSP). These trackers hold mounted mirrors that reflect sunlight to a central collector tower containing hot liquid or gas. They are also a key element in concentrator photovoltaic (CPV) installations that use parabolic mirrors or lenses to focus sunlight (and even ambient light from the sky) into solar collectors that are part of each unit. These panels and mirrors require precise angles to enable optimized concentration of the light onto a fixed-location tower, into Fresnel lenses, or into a solar thermal collector. The tracking system may be centralized, where a single motor moves many rows of panels at once, or a distributed system, where an individual motor moves one row or table of panels.

Horizontal single axis trackers (pictured above) are better suited for lower latitudes. (Source: Energia Solar)

Solar tracking devices can be classified by the number of axes around which they rotate and by their orientation. Horizontal single axis trackers (HSATs) are horizontal to the ground and mounted on rotating tubes supported by pylons or frames. Horizontal single axis trackers with tilted modules (HTSATs) are similar but installed at an angle, for higher latitudes, but rotate the same way. Vertical single axis tracker (VSAT) panels, also for higher latitudes, rotate around a vertical axis, but the layout must be designed to prevent the rows of panels from casting shade on each other. A hybrid horizontal/vertical tracking system is referred to as a tilted single axis tracker (TSAT).

A tilted single axis tracker is a hybrid of horizontal and vertical tracking systems. (Source: The University of Queensland)

In addition to the panels or mirrors, tracker hardware may include steel posts or rails, cables, junction boxes, slew drives to rotate the panels, and hydraulic dampers to provide flexible resistance against the wind. The structures must be robust, well-anchored, easily transported and installed, and must be able to withstand the elements, including hot or cold locations, strong storms, heavy rain or snowfall, and even seismic activity.

Perceptions of solar tracking

For a time, solar tracking for large-scale installations had a reputation as a more expensive and maintenance-intensive technology despite the higher energy capture rates. Some of these reliability perceptions still linger. In actuality, according to Greentech Media, solar tracking systems boast a 99.9 percent uptime rate and advances continue in mechanical functionality and software-based optimization. In fact, the U.S. Energy Information Administration reports that of all utility solar projects constructed in the US in 2016, 79% used solar tracking rather than a fixed panel.

Advances in solar tracking

Despite being perceived as a less exciting infrastructural component of the solar industry, solar tracking has seen a number of technological and mechanical breakthroughs that promise increased growth due to lower costs and increased weather resistance.

One of the challenges is the economics of land use and site preparation. Until recently, utilities and third-party solar farm developers had to plan carefully to ensure that the needed amount of power could be generated from a particular site size given solar tracker configurations (e.g. HSAT vs VSAT). Additionally, they had to take into consideration the site contours and how much grading and preparation would be required to adapt the site to optimized solar tracker deployment. As a result, there has been stiff competition for flat sites.

Utilizing slopes and rolling terrain

In California, a company called Nevados Engineering is on the verge of launching single axis trackers designed to work on south-facing and sun-facing slopes and varied terrain, which offer better solar exposure. The company’s All Terrain Tracker (ATT) technology uses unique bearings that allow articulation with the driveline so it can fit the terrain using the same kind of posts as on flat land. Every post in the row is used to withstand the slope load, which is the toppling force exerted by the structure being pulled down the hill by gravity. The tracking units can handle slopes of over 20 degrees and can also handle side-to-side, and vertical, post misalignment of up to two feet. The advance vastly reduces the need for grading and landscaping, enabling solar developers to purchase significantly cheaper sloped or contoured terrain to maximize solar energy capture.  The company’s software enables developers to predict solar production for a site to calculate the economics.

Nevados Engineering’s All Terrain Tracker technology and help install solar trackers in all kinds of terrains. (Source: LA Cleantech Incubator)

“We need to look beyond what we expect solar trackers to do,” said Yezin Taha, CEO of Nevados Engineering. “Installing trackers on a slope can capture 7% more solar energy than trackers on flat ground, and 32% more energy than fixed tilt systems.”

Leveraging non-standard sites

Another recent development, floating ground mounts, has also made more large-scale solar sites available. While most solar trackers are mounted on posts that are driven directly into the ground or less frequently, on posts that use concrete foundations or ballast, certain kinds of terrain won’t support driving posts or invasive concrete structures. These sites, such as capped landfills, can be highly suitable for solar installations due to their height, restricted access, and unsuitability for other uses. The development of floating ground mounts, where the tracker is placed on a gravel pan that can be filled with a variety of materials, has made possible the use of these kinds of sites where posts can’t be driven.

Resisting the elements

Advances in resistive materials also show promise for the solar tracking industry. Posts and other tracking components are typically made of galvanized steel, which means they are coated with a high zinc content layer. Galvanization has been the most weatherproof and anti-corrosive solution to-date, but it still allows rust to form over time. Moisture can be an electrolyte that enables galvanic corrosion to occur, so that as humidity increases, the rate of corrosion increases. Also, atmospheric contaminants can catalyze the chemical reaction. Chlorides in marine environments, as well as and sulfur dioxide and nitrous oxides in industrial locations, may present a higher risk of corrosion.

Recently steel companies such as POSCO have begun to add magnesium to the coatings for further protection, a process that had been prohibitively complex until now.  POSCO’s PosMAC is a combination of zinc, aluminum and magnesium that “heals” any exposed parts of the steel by forming a layer of simonkolleite, a stable compound, over the vulnerable area. The development promises greater ruggedness and durability for tracking components.

Streamlining operations and maintenance

Finally, the advent of sensors, drone-based inspections, and the Internet of Things (IoT) will have a growing impact on solar farm operational costs by enabling remote monitoring, hardware predictability, just-in-time replacement and streamlined functioning. An operator in Germany could easily determine when to clean the solar panels in a Dubai installation after a dust storm or know when a tracking mechanism becomes jammed.

Solar tracking mechanisms can be monitored easily with the help of artificial intelligence. (Source: Micro Power Grids)

These advances, coupled with the cost efficiencies of solar and the increasing availability of grid-level energy storage solutions, will continue to boost the utility-scale solar energy market and take market share from fossil fuel power plants. The expansion of solar power offers a significant opportunity for multiple industries, from materials providers to solar panel manufacturers, tracking system component manufacturers, sensor distributors, battery makers, software developers and even drone suppliers. By leveraging the confluence of these technologies each industry can ensure that they participate in the solar market’s return on investment.

Tom Breunig is the publisher of Cleantech Concepts, an online magazine and market research firm tracking cleantech R&D and innovative business models.

Under the agreement, POSCO Daewoo will supply solar panel modules produced by Hyundai Heavy Industries (HHI), for installment on general houses and skyscrapers across the U.S.

The global business network and financing capability of POSCO Daewoo, together with HHI’s diverse array of manufacturing technologies, have been the driving force behind the success of this contract.

As interest in eco-friendly energy increases globally, the demand for solar panel modules is steadily rising. POSCO Daewoo is utilizing its abilities on building a value chain of its solar power business by carrying out various projects for related materials, ranging from raw material for the solar panel modules (such as polysilicon), intermediary materials (cells), to the finished products.

POSCO Daewoo has focused on landing new business partners through local subsidiaries, which they think have been the main factor in beating lower-priced and leading competitors. The company hopes to participate in future projects with American solar power firms as well.

Since 2010, POSCO Daewoo has been running its renewable energy division and is seeking to emerge as a forerunner in the area of sustainable energy trade both intra- and inter-nationally.

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With an aim to strengthen POSCO’s solutions marketing and World Premium products in India, POSCO-INDIA (President, Mr. Gee-Woong Sung) will take the role as the regional representative of POSCO. Responsible for the marketing of PosMAC, it has already entered into sales agreements with a few Indian clients.

The Future of PosMAC in India

In the past few months, POSCO-INDIA has secured the supply order for 300 tons of PosMAC, and the first consignment will arrive by December. A huge jump in the sales volume is expected in 2016. Together with POSCO-IDPC, POSCO-INDIA’s target is to promote and introduce PosMAC to its existing Engineering Procurement Construction (EPC) and Independent Power Producer (IPP) clients. It will also gradually increase the sales volume in India by partnering with other big players in industries ranging from general engineering, automobile and home appliances. The solar power industry is also one of the main focuses for PosMAC in India. In January 2016, POSCO-INDIA is planning to organize a PosMAC technical seminar for potential local clients, with assistance from POSCO HQ and other family companies within India.

At present, two rooftop solar panel structures using PosMAC steel, with 75000 Kwh annual capacity, is being installed at the POSCO-IDPC plant in Bawal. It is considered to be the pilot project for introducing PosMAC in India, intended to showcase these solar units to potential PosMAC clients. The completion target is February 2016 and upon completion, both units will cover the power requirements of the administration and canteen building at IDPC plant.

POSCO-INDIA believes that PosMAC can become popularized for use in the solar panel market in India. Because it is less expensive than other corrosion-resistant materials such as stainless steel, PosMAC steel is highly sought-after for its strength, durability and affordability, which is a key deciding factor for the price-sensitive market. Additionally, PosMAC steel will significantly lower costs by eliminating the need for frequent replacement.

The Benefits of PosMAC Steel

It is well known that steel is essential to modern life and to a future of sustainable development. Nevertheless, it is susceptible to inevitable obstacles. Steel corrodes when exposed to certain conditions. As the industrialized world looks into ways to prevent corrosion, POSCO’s unwavering focus on R&D of steel material products resulted in PosMAC. It is a ternary alloy coated steel with high corrosion resistance developed using POSCO’s own technology and is five to ten times more resistant than normal hot-dip galvanized steel sheets (GI, HGI) of the same coating weight. This means it can replace normal thick plating products.

A tropical country surrounded by ocean on three sides, India has varied climatic conditions, exposing steel structures to environmental corrosion. PosMAC is an appropriate solution to such situations, as it guarantees more durability and resistance to rust and corrosion than existing versions of steel. In 2014, the Prime Minister of India, Mr. Narendra Modi, set a target of 100 GW of solar generation capacity by 2022, nearly a 33-fold increase from the current capacity. This announcement generated the interest of many private companies in India’s solar power sector. POSCO-INDIA expects to offer PosMAC as a durable solution to corrosion resistance in India.

POSCO-INDIA is committed to enhancing competitiveness for its customers by offering technology, business know-how, marketing support and other assistance to its clients. PosMAC will take the lead in a new era of innovative, premium products developed by POSCO.

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Growing Need for Rust-free, Corrosion-Resistant Steel

Steel is an essential industrial material, but exposure to water, salt, or oxidation can cause it to rust. Rust and corrosion can drastically reduce the safety of buildings by posing a constant potential threat to their structural stability. Additionally, rust has a negative effect on the aesthetics of a structure and its surrounding environment. There has been a jump in interest and demand for corrosion-resistant steel to avoid the high costs of frequent maintenance and replacements.

POSCO Presents Ultra Corrosion-Resistant PosMAC Steel

POSCO’s undying focus on the research and development of steel material products has produced PosMAC, a revolutionary plated steel sheet that is five to ten times more resistant to rust and corrosion than existing versions. The product is an upgrade of existing generic plated steel imbued with resistance to the corrosion of the cut edges that is superior to competing products in strength and resilience. This innovative product, PosMAC represents over 30years of technological progress in the field of steel plate production, as well as POSCO’s commitment to the research and development of ultra-resistant steel plates for the past six years.

PosMAC, or POSCO Magnesium Alloy Coating Product, is an ultra-corrosion resistant alloyed steel plate developed with unique POSCO technology. One of the world’s highest quality steel surface treatment products, PosMAC is five to ten times more resistant to rust and corrosion than existing alloyed steel plate products. Being less expensive than other corrosion-resistant material such as stainless steel, the revolutionary PosMAC steel is highly sought after not only for its strength and resistance but also for its affordability.

PosMAC: Resistant to scratches and steel cut edges corrosion

Existing rolled steel is vulnerable to steel cut edge corrosion

PosMAC is highly resistant not only to rust in general, but also to alkali, scratches and steel section corrosion, thanks to PosMAC’s superior steel plating technology. The magnesium in PosMAC’s plating accelerates the formation of highly stable corrosion products, which in turn forms a layer on the surface of the steel plating, preventing the steel plate from corrosion. While existing rolled steel are vulnerable to steel cut edge corrosion, PosMAC’s steel edges form a protective layer from corrosion products after six months, preventing steel cut edges from forming corrosion. This makes PosMAC five to ten times more resistant to corrosion compared to existing products, as well as giving it resistance to steel cut edges corrosion, a unique advantage not found in other general plated metal products.  Furthermore, PosMAC is highly resistant to alkali and ammonia, which makes it highly suitable for use in livestock handling facilities or in situations where components are in contact with concrete tar.

Let’s have a look at the various applications of PosMAC technology

Reducing production costs of solar panels

PosMAC is being highly sought after in the solar panel market for its high resistance and affordability

The demand for highly durable PosMAC is on the rise in the solar panel industry where solar panel structures are expected to be fully functional for up to 20 to 30 years from their installment. We expect PosMAC to become highly popular in the solar panel market: the plated steel used in the manufacture of supporting fixtures of solar panel structures are extremely costly, and using highly durable and resistant PosMAC steel will significantly lower costs by removing the need for frequent replacement.

Manufacturing automobile motor cases with PosMAC

PosMAC is used for motor cases which require extra-high resistance and durability

POSCO is also offering PosMAC as a solution for automobile components that require extra-high resistance and durability such as ABS, power windows and motor cases. PosMAC will take the lead in a new era of more durable and long-lasting automobiles!

The PosMAC Initiative: Expand PosMAC’s applications

PosMAC has been expanding its market presence mainly in agriculture/livestock/fishing, solar panels, motor cases, and road facilities. Now it’s time for the next phase of the PosMAC Initiative: plans to expand PosMAC’s applications to home electronics and automobile steel plates are under way!

POSCO takes the lead in a new era in the steel industry with PosMAC, the revolutionary product developed through years of research and development. POSCO will continue its commitment to leading the global steel market with the highly resistant and durable PosMAC.