Light towers are a key piece of equipment on construction, mining and outdoor public event sites, providing illumination for numerous applications and projects that need to be carried out in a safe manner during hours of darkness or poor visibility.
In terms of power source, diesel-driven light towers remain very popular, accounting for as much as 75 per cent of the market. They are widely seen as the ideal solution when working in remote locations, where access to electricity is limited or non-existent.
The diesel engines used to power light towers typically have a rated output from 3 to 6 kW, providing more than enough power to run the metal halide or LED lamps for extended periods of time. These engines are much smaller than those used for other Atlas Copco products such as compressors and generators, and therefore feature a less complex engine architecture. This has made the transition to Stage V compliance far simpler than in other sectors, with no need for additional after-treatment to meet emissions standards. Indeed, from April next year, all diesel-driven light towers will be Stage V compliant, with the new engines continuing to offer exceptional levels of fuel efficiency and reliability.
While diesel remains the primary power source for light towers, there is a full range of complementary technologies that are better suited to certain applications. Electric-only light towers like the HiLight E3+ are a good solution for work sites with reliable and accessible grid connection, ensuring that lighting operations are carried out without the interruption of refuelling or additional maintenance required to service mechanical parts. These electric-only light towers are regularly used on metropolitan construction sites, as they are typically quieter and smaller than diesel-powered models.
Battery-powered LED light towers are also coming to the fore, with advances in lithium-ion technology resulting in improved energy density. Atlas Copco’s new HiLight Z3+ battery-powered light tower, for instance, offers up to 20 per cent more depth of discharge in comparison to AGM and OPzV battery types, with a maximum energy density of 190 Wh/kg compared to 50 Wh/kg, and a lifetime of 5,000 cycles; equivalent to twice that of the best alternative technologies. This delivers best-in-class performance in terms of running hours, reliability and total cost of ownership, providing a 40 per cent advantage over diesel hybrid systems in terms of overall energy efficiency.
Looking further forward, solar-powered light towers offer the potential of truly environmentally friendly illumination in urban areas. This remains an active area of research and development within Atlas Copco, but solar technology requires further development to overcome a range of issues. For instance, the batteries can be unpredictable in terms of the power they can accumulate from solar panels. Furthermore, the replacement of solar panels is quite expensive, and their endurance for 24/7 x 365 operations remains unproven.
Solar-powered light towers can also prove rather difficult to install, mainly because a large work surface is required to maximise the number of solar panels to reduce recharging time.
For the time being, then, diesel, electric and battery power look set to continue to make up most of the market for light towers. This provides Atlas Copco customers with a full set of complementary technologies, whatever the application.