Blog: Solar Tracker O&M Considerations for the Middle East and North Africa

Solar Tracker O&M Considerations

Photo above featuring Sakaka Solar Power Plant, Al Jouf, Saudi Arabia, 405 MW, featuring NX Horizon smart solar tracker

Blessed with infinite irradiance and increasingly impressive project economics, the Middle East and North Africa (MENA) region has become prime real estate for solar and storage projects. The data from Wood Mackenzie bears this out, as the research firm confirms MENA as one of the hottest emerging markets for large-scale solar in general and the strongest growth market for utility-scale trackers in particular, with compound annual growth expected to exceed 30% over the next five years. To get a sense of a large-scale plant we’ve just commissioned in Al Jouf, Saudi Arabia, watch this video below. It includes aerial drone footage of the plant in the desert and tells the story of what’s involved in the development of a utility-scale solar plant in the region.

Along with the rapid deployment of gigawatts of PV in countries like UAE, Oman, Saudi Arabia, Jordan, Egypt, and Morocco comes the need to operate and maintain those solar plants, and like other regions, MENA brings its own set of unique asset management challenges.

Those challenges were the focus of many discussions at the recent Solar Plaza’s Asset Management MENA conference. One key takeaway: the way in which sand and dust behave in the Middle East is not the same as other places. Soiling is a major issue. Because of the region’s unique cocktails of particulate matter, extreme heat, humidity and other climate conditions, sand and dust can turn into a cement-like coating on the glass of a solar module and most likely within other operating components of a solar plant.

In fact, the term “cementation” is the process of dust particles sticking to one another—and to the surface of a PV module. Other factors affecting this dense soiling mechanism are humidity and dew point. The chemical nature of the dust particles themselves changes when water is present, and the particles then become stuck to the module glass and are difficult to remove. When this type of caking is allowed to build up, it’s extremely detrimental to the module performance and overall power generation suffers, O&M expenses and cost escalate, and the levelized cost of energy (LCOE) goes up.

The solution to cementation and soiling is regular cleaning, and Nextracker’s independent tracker row architecture facilitates a variety of cleaning solutions. In much of MENA, that means a monthly maintenance schedule. Although large work crews performing manual cleaning will still get the job done, there have been significant advances in semiautomatic and automatic robotic cleaning systems for both one-in-portrait (1P) trackers like NX HorizonTM and two-in-portrait (2P) trackers like NX GeminiTM. Trackers also have an advantage over fixed-tilt installations in dealing with soiling because they can be tilted and stowed in such a way to use the wind to help clean the modules or to reduce dust adhesion by adjusting tilt angles.  NX trackers can be designed end-to-end, and the independent row architecture enables robots to move to adjacent sections to leverage 2 km or more of cleaning per robot charge.

Robotic cleaning compatibility for Nextracker’s solar tracker portfolio.

The long-term impact of intense heat, high winds and soiling must be factored into system design and component selection as well. One tracker size does not fit all. You need the right design and system for each area, with tweaks and adjustments made for the particular environment. For example, the drives on our independent-row trackers are sealed and not exposed to the elements, since they are situated in self-contained, dust-tight IP65 enclosures. Even seemingly benign components may require a region-specific solution, such as cabling and cable ties, which should be made of ruggedized UV-resistant materials that won’t deteriorate in the open desert.

Wind is also a critical consideration in plant design in MENA. Like many places elsewhere on the planet, it is strongly recommended to perform site-specific wind analysis in this region. Wind failures can cause major downtime issues when sites or portions of sites become non-operational, and the losses can outweigh additional spending on CAPEX and O&M and negatively impact the LCOE over the lifetime of the plant. Best practices for designing for the wind and sand must account for challenging soils, undulating terrains, high winds, irregular site layouts, and ease of cleaning and maintenance of the tracker systems. We believe the wind factor will play a major role in maximizing uptime in the region. Nextracker has been investing heavily in wind testing and analysis and works with its partners and customers to find the best solutions for each site.

A brief note on performance. Trackers improve energy yield, and Nextracker’s systems have been designed to maximize yield gain using the patented, adaptive intelligent control system TrueCaptureTM (adding 2-6% typically), which has been incorporated on over 40 projects globally. As for bifacial gains, NX Horizon outperforms traditional 1P trackers and adds 1-2% on top of the TrueCapture yield gains because its balanced design enables highly elevated modules above round tubes, and away from piers, bearings and drive systems. Maintaining uniform illumination on the rear of the solar panels is essential for optimized bifacial performance.

One of the key tools needed in the MENA region for a professionally run O&M and asset management teams will be data connectivity and communications. As I like to say, connectivity is king. In order to fully reap the performance and operational benefits that smart trackers provide to the plant, a monitoring system with data analytics platforms like Digital O&M and TrueCapture needs to be connected to a secure cloud-based data center, so that equipment manufacturers can help effectively co-manage the solar assets and maximize the asset owner’s returns.

(Nextracker will be participating at the World Future Energy Summit [WFES] in Abu Dhabi, Jan. 13-16, 2020. We’ll be in the expo hall at Stand 6120, and our CEO Dan Shugar, VP Jitendra Morankar and myself will be speaking at the conference.)