In regions with strong sunlight, such as the Middle East and Australia, this solar light tower is completely autonomous, fully recharging in six to eight hours. Elsewhere, a tower’s autonomy can be extended to up to 20 hours thanks to a modular design that allows the number of batteries installed to be upgraded. In regions with little sunshine in the winter, the unit requires supplementary charging from a battery energy storage system, such as the Atlas Copco Zenergize ZBP45.

“Many customers are really committed to reducing their CO₂ footprint, and others see that if they don’t minimize their emissions, they will be out of the game,” says Felix Gomez, Product Marketing Manager in Atlas Copco’s Power and Flow division.

Wings of a bird This sustainable innovation is the result of a collaboration between the Power and Flow team in Zaragoza, Spain and the manufacturing team in Wuxi, China. The new features are based on the customer response to Atlas Copco’s first solar light tower, the QLTS, which came market in 2014. The development project was a collaboration between the Power and Flow team in Spain and the manufacturing team in Wuxi, China. Designed for difficult terrains and crowded construction sites, one of the improvements is the extendable panels that can be folded inside the canopy to avoid damage during storage and transport. According to Qiangwx Li, Engineering Manager in Wuxi, the extendable panel solution was inspired by nature’s own design. “It came like a flash into my mind, and I thought that the machine could expand, like the wings of a bird, and then when it's not being used the panels can be stored inside,” he remembers. “It means you can tow it anywhere without worrying about the solar panels cracking or being hit by a stone, and it also makes the whole machine neat and easy to store.” This solution presented a complex engineering challenge for He Chi, Engineering Team Leader, particularly as the panels needed to adjust to face the sun. “It was so difficult,” she says. “I needed to design a solar panel expanding system which allows solar panels be stored in one rack, in four layers, but which could be expanded to 5.4m wide.” Apart from one month of the design process, when Wuxi was in pandemic lockdown, He Chi came into the factory frequently to test various solutions. “I’m so excited,” she adds of the first deliveries to customers. “It’s like my child.” Compact footprint Apart from the obvious climate benefits, the HiLight S2+’s zero noise operation is a key advantage, not least in housing areas or at major public events. The light tower’s low maintenance also appeals to mining companies. Whereas a standard diesel light tower needs frequent refueling and a change in oil filters every 500 hours, the S2+ is close to maintenance-free. In the event of a fault, the canopy flips up, giving easy access to all batteries and wiring. The light coverage is a third of that produced by Atlas Copco's popular HiLight H6+ diesel towers, so for some construction sites the S2+ is best used to light non-critical areas such as worker accommodation and parking. A light tower with greater coverage would currently be too expensive and take up too large an area, but with solar and battery technology improving rapidly, this will change.