2016 | NORTH AMERICA | USA | 38 MW
SF Utility tracker equipment supply and installation for project developer Isolux Corsan.
bahia soltec solar pv panels tracking plant 158 MW - Soltec
SF Utility tracker equipment supply and installation.

Horizontal Single-Axis Trackers: A Brief History


Horizontal Single-Axis Trackers: A Brief History

The horizontal single-axis tracker has evolved commercially since the eighties, when 357 MW of solar thermal electric horizontal single-axis tracker power plants were constructed in the Mojave Desert, in the US state of California.

Ten years later, horizontal single-axis tracker commercialization got bigger for photovoltaic applications. Some developers started to switch their choice regarding photovoltaic fixed-array versus tracking-array and it began to favor the tracking equipment, mainly due to the high cost of silicon photovoltaic and the horizontal single-axis tracker irradiance capture performance increase of 22% to 32%.

The primary disadvantages of tracking were the apparent increased risks and expenses of mechanical complexity, in opposition to the simpler fixed installation. Fixed systems could be placed properly and maintenance would not be practically a problem for the next two or three decades. Tracking, on the contrary, meant engines and components, moving structures and electricity bills, as well as the related equipment controllers, boxes, wiring, protections and monitoring devices.

The early commercialized horizontal single-axis solar trackers were a linked-row drive system type, with around one grid-powered engine per 500 kWp of photovoltaic mounted on several connected torque-tube structures. This design can still be found in the horizontal single-axis tracker photovoltaic market.

Five years ago, the independent-row horizontal single-axis PV tracker design entered into commercialization, gaining remarkable adhesion in the market. The mechanical disadvantages are pretty well accepted now that the installation and operation past performance of horizontal single-axis tracker photovoltaic is satisfying its promise. In the present-day market, duly hard-working entities will back economically horizontal single-axis tracker solar projects despite the fact rigorous EPC criteria must be applied.

Market experts accept as true that horizontal single-axis tracker will take the lion’s share of the awaited utility-scale photovoltaic projects market over 2020.

Those developers considering single-axis solar trackers, and chasing biggest bang-per-buck on the bottom line of profit, recognize that not all horizontal single-axis tracker equipment is the same.

They usually take into account these three crucial and related aspects:

1. Maximum yield potential, which is more than only power-fill on the PV tracker. The independent-row type of trackers offers better site-fill yield potential. Look for 120⁰+ tracking range and configuration choices providing uppermost tracker power-fill.

2. Land-use possibilities, which directly influence on yield potential. Look for high-slope tolerance on the North-South axis where yield can be improved, but where it may be expensive or not possible to install solar trackers. Irregular lands, those with short-steps, contours or not-square property, may be tricky. Look also for better installation tolerance on these lands combined with smaller standard-blocks that will spread more into increased yield; together with the ecological and financial benefits of a lesser amount of grading and any other civil work.

3. Low-cost installation and O&M (operations and maintenance). Look for great assemblage tolerances at the critical pile-tracker interface, where misalignment may origin installation refitting and rescheduling. Look also for a minor piles-per-MW amount to decrease initial expenses and ecological impact of construction. And finally, look for self-powering supplies, broader corridors between tracker-rows, and the newest communication technology in local and wide area grids.

Not only their products but also photovoltaic specialist companies of the United States utility-scale sector have progressed. Although solar PV trackers remain far from its potential in application, this sector now has the right product to a promising future.