Over the past few years, the use of solar trackers has become more mainstream and accepted by the solar industry. Quality-built and smartly designed trackers have all but eliminated perceived risks of tracker use. Successful tracker designs are typically less complex and can be mechanically linked together to minimize active components to maximize performance, reliability, and long-term maintenance issues.
Innovation in solar tracking technology in the past year has focused, in part, on achieving the most efficient use of materials while maintaining reliability. As a result, trackers now decrease install times, minimize labor costs, and produce a competitive leveled cost of energy (LCOE).
For example, the DuraTrack HZ single-axis tracker from Array Technologies (ATI) has been installed in more than 200 utility-scale and commercial projects around the world, a success that can be attributed in part to its patented rotating gear-drive design.
The design calls for multiple rows of PV modules to be connected by a rotating drive-train, which is powered by a motor. This drive-train turns several rows of modules to track the sun throughout the day. The design provides siting flexibility for varied terrain conditions as the drive-line can be installed at varying angles. It also uses fewer motors per megawatt, which increases long-term reliability by reducing potential failure points.
In today’s competitive landscape, tracking and racking brands are marketing to their individual strengths, such as site flexibility, reliability and faster installation. Ultimately, clients are searching for creative ways to bring down BOS costs while increasing value.
Photo courtesy of Array Technologies
Reflecting this last point, Paul Breslow, director of marketing at robotic-powered tracker company QBotix, says optimization, which leads to greater value, is a trend that has been implemented across the entire solar industry.
“In inverters, it is evidenced by the growth of micro-inverters, DC optimizers and string inverters for residential and commercial project sizes and situations where these technologies provide a quantifiable value proposition,” he says. “Similarly, not every mounting system works equally well in all situations.”
Breslow says a ganged actuation single-axis tracker that works well in a 100 MW site near the equator may not result in the best project economics for a commercial-scale or sub-10 MW utility scale project at a 30 degree or more latitude. To optimize within the mounting industry, QBotix developed the Robotic Tracking System, or Qbotix RTS, a dual-axis tracking system that employs rugged, intelligent, mobile robots to aim solar modules toward the sun and adjust their position throughout the day to maximize energy output. The RTS can be installed at higher GCR’s and in complicated field situations.
According to Array Technologies, the market landscape in 2014 has shifted toward projects in the 1 MW to 20 MW range, which will meet utilities’ short-term capacity needs and remaining RPS requirements. With the ITC end date in sight, developers have little time to start permitting new multi-megawatt projects with inherently longer development lead times.
The increase in mid-sized sites will support continued growth in the tracking and racking market, as they will also create ground-mount needs, which suppliers are already fulfilling. In addition, new markets have emerged in support of solar, such as North Carolina and Georgia, which add geographic diversity to the solar industry in the United States.
Solar trackers will be fundamental as solar becomes more mainstream because tracking technology allows a PV system to broaden the power-delivery profile with peak production delivered during peak energy demand times.
The increased production from trackers means they provide proportionally better economics when the value of the kWh is higher. With incentives coming down in many historically strong markets, this could cause some short-term situations in some markets and geographies where tracker value propositions are not as strong as fixed-tilt, according to Breslow. However, market fundamentals dictate that energy prices will continue to rise, and this provides strong justification for tracking being the optimal long-term solution in many markets.