Author: Jason Deign
A burgeoning pipeline of solar projects means Spanish developers will have to focus on trackers to ensure the best returns from their plants.
Don’t be fooled by Spain’s latest auction results. Despite a lackluster showing for solar, PV is booming in the Spanish market, forcing developers to focus on technology in a bid to maintain profitability. This may not have been obvious from the second Spanish renewable energy procurement round in 2021, which saw just 866MW of a total 3.1 GW of capacity going to solar.
The muted response from solar developers was partly due to some large bidders pulling out of the contest in protest at government measures to limit windfall profits from renewable plants. But, increasingly, developers are sidestepping the government altogether on their way into the Spanish market. According to SolarPower Europe’s 2021 Global Market Outlook, Spain has a pipeline of more than 100 GW of solar power under development, up from 14 GW of total capacity in 2020.
Much of upcoming capacity in Spain is being developed on a merchant basis. “This makes the country probably the world’s largest market for subsidy-free solar,” says SolarPower Europe.
A Haven for Merchant Solar Developers
Merchant plant developers are attracted to Spain because of its excellent solar resource, one of the best in Europe, and growing demand for clean power as thermal units are retired from the grid. The ability to produce solar energy at below spot-market prices is enhanced when developers use trackers and the latest PV module technology. Full compatibility between modules and trackers is a key factor to guarantee the installations’ efficiency and minimized operation and maintenance (O&M) costs.
One of the biggest contributors to solar power cost reduction in recent years has been a move to bigger, more efficient panels. Larger panels mean the same installed capacity with less equipment needed. With a Trina Solar Vertex DEG21C.20 module, for example, delivering 670 W of power compared to 545 W for a reference model.
However, larger modules impose higher stresses on tracker systems, which are typically designed to be as light and flexible as possible. In Spain’s vast, windswept interior, pairing larger modules with standard tracking systems risks exposing the plant to critical infrastructure failures, particularly as Spain, as other European countries, experiences more extreme weather resulting from climate change.
Improvements in Solar Tracker Design
Thankfully, though, tracker technology is advancing in lockstep with module design. TrinaTracker, for example, has designed its latest products in collaboration with two of the world’s leading wind engineering consulting firms, CPP and RWDI. As a result, TrinaTracker Vanguard 2P and Agile 1P designs are defined according to results obtained through extensive wind tunnel tests to ensure the trackers’ efficiency and structural integrity when mounted with large format modules, and under extreme weather conditions.
In TrinaTracker’s single-axis Vanguard two-in-portrait (2P) model, for example, torsional moments are distributed across an optimized number of posts to improve stiffness and prevent aerodynamic instabilities. Wind tunnel tests have also helped TrinaTracker to devise optimal stow positions for different types of trackers. Thus, the Vanguard 2P stows modules at a 0-degree angle while the single-axis TrinaTracker Agile one-in-portrait (1P) system, which features two rows of modules per tracker, uses a 45-degree stowing position because this has been shown to be more stable.
While module size is a critical factor to consider when selecting a particular tracker model, it is by no means the only one. In Spain, for instance, the sheer scale of the country’s solar buildout and a paucity of adequate grid connection points means developers will increasingly be forced to build projects on suboptimal plots, including hillsides and slopes. Here, it will be important for tracker technology to adapt to any kind of terrain complexity.
Fitting Into a Range of Locations
TrinaTracker already builds tracker systems that can be adapted to a variety of terrains. The Vanguard 2P, for example, can be installed on a 15-degree slope while the Agile 1P can go up to more than 20 degrees. Both models also feature a patented spherical bearing, which can move around three axes of rotation, allowing trackers to become self-adjusting and to adapt to uneven terrains while cutting tracker assembly times by 50% per post, or 15% overall.
In addition, the Agile 1P tracker has a post profile that can be customized for a given terrain. This ability to adapt to varying site conditions has an impact on what is undoubtedly the most important consideration for Spanish merchant solar plant developers: achieving the lowest possible levelized cost of energy (LCOE).
Allowing for installation in a range of locations can help cut LCOE, for example by allowing developers to build on cheaper sites and reduce land costs, or exploit uneven terrains close to available grid connections. Furthermore, modern trackers often incorporate a range of features designed to reduce LCOE. TrinaTracker’s spherical bearing is one example. By simplifying installation, it can help reduce solar balance of system costs by $0.029 per watt.
Design Features to Optimize LCOE
Furthermore, both of TrinaTracker’s tracker lines can be optimized using a SuperTrack algorithm in the supervisory control and data acquisition system, increasing yield by up to 8%. The Agile 1P tracker system also comes with a proprietary Trina Clamp that can cut installation time by up to 50%. Finally, LCOE can be reduced by cutting the number of components required per megawatt of solar capacity, since this reduces the amount of maintenance required. For this reason, tracker makers have sought to make the technology simpler as well as sturdier.
TrinaTracker, for example, has almost halved the number of 2P trackers needed to support a megawatt of solar panels, from 33 previously to 17 with the Vanguard model. At the same time, the manufacturer has slashed the number of tracker motors per megawatt by 50%, cut the number of bearings by 49% and reduced the number of bolted joints by 26% in the new 2P single row Vanguard design.
This all reduces the number of potential failure points per megawatt of solar capacity, reducing likely maintenance costs. As a result, TrinaTracker estimates its Vanguard trackers will have around 33% lower operations and maintenance (O&M) costs than previous 2P models, while the Agile 1P will cut O&M expenses by up to 25% compared to its previous design version.
Such developments will no doubt be welcomed by Spanish developers looking to compete in an ever more crowded market.