As the world turns to renewable energy sources, solar PV has taken top spot as a technology homeowners and business owners can call their own. Rooftop PV systems can be found on more than 2.2 million homes around Australia, with some postcodes hosting more than 10,000 systems and close to 50MW of capacity. It’s a growth trend that isn’t about to stop. Over the past 10 years, the national average system size has grown from 1.34kW in 2009 to 7.13kW in 2018.
At utility scale it’s a slightly different story. At the end of 2019, nearly 50 solar plants accounted for 3.2GW in the NEM, versus 6.8GW of capacity for commissioned wind farms. As the powers that be focus their attention on transmission upgrades that will free up parts of the country where solar plants make obvious sense, even more utility-scale PV will come flooding into the grid – hopefully augmented with storage.
The market for the seemingly simple componentry essential to a PV system is highly competitive as R&D teams search endlessly for any tweak that will deliver a smidgen of extra yield. It’s this relentless pursuit of efficiency that has seen the average price of PV modules drop by 90% over the past decade, from $US2.18/W to US27c/W, according to PV Evolution Labs.
Chinese solar firm Trina, which has been chasing the sun since 1997, this year launched a 166mm wafer it says will see output of 445-450W for a 72-cell panel compared with 405-410W for a 72-cell panel using a 158.75mm wafer.
When the new technology is launched next year, Trina Solar director of sales and marketing for Asia Pacific Ku Junheong says owners of residential systems using 60-cell modules could expect savings of about 2%.
“Your entire saving for the balance of system – structure, cabling, number of panels to be installed, labour – all of this will be reduced by about 2%,” Ku told EcoGeneration during the All-Energy exhibition and conference in Melbourne in October. He anticipates a similar result for large-scale projects. “That will be a direct saving for the developer and EPC companies.”
In its efforts to find deep efficiencies for developers of large projects the company has launched TrinaPro, which offers one contact to buy high-output modules with smart PV controllers and trackers, smart inverters and digital cloud-based operations and maintenance software.
Trina Solar’s first utility-scale project using TrinaPro is a 250MW plant in China’s Shaanxi province.
Ku says TrinaPro makes sense in markets were projects may be located far away from major cities and towns, which means transporting modules and other parts to these places can be a logistical challenge.
“Solar farms make use of the plentiful land available outside major Australian cities, but the distances involved makes delivery, operations and maintenance more complex,” he says. “TrinaPro responds directly to these challenges by offering simplified installations, single window delivery and warranty.”
Data monitoring, data analysis and predictive maintenance for the installed solar system is also streamlined, helping to see that the solar system operates efficiently.
From both sides
Bifacial modules are also making an impression, especially when they are included in systems with single-axis tracking.
The integration of smart trackers into TrinaPro can provide up to a 6% power boost for Trina Solar DuoMax bifacial solar modules by angling them to reduce the effect of shading, the company claims. Tracker technology can also be used to protect solar panels from hailstorms, as trackers can angle panels perpendicular to the ground so that chunks of ice don’t smash squarely onto them.
Ku reckons Trina’s intelligent tracking system, working with inverters, will enhance output by 3-5% compared with regular single-axis tracking. Professional relationships with select inverter makers has allowed Trina access to source code, so extra optimisation code can be added between tracker and inverters. “We always find the optimum Q angle against the sun,” he says.
Typical tracker algorithms use astronomical algorithms, where the location of the sun is calculated based on the geolocation, using GPS, and the time of day. When sunlight is diffuse, however, it may not be best to angle a module directly towards the sun. A smart tracker will measure direct sunlight and diffuse sunlight to determine an optimal angle.
For bifacial modules, measuring diffused sunlight reflected off the ground is also an important factor.