Atlas Copco introduces Integrated Hybrid gen sets

A graph outlining tower crane power consumption would generally chart a low average load interspersed with short, but very high peaks of energy draw. Because of these draw peaks, diesel gen sets used to power tower cranes are usually oversized so they have the capacity needed to support these brief power spikes.

This characteristic of peaking demand has prompted tower crane operators to use battery energy storage systems (BESSs) for their power supply. These can support the power spikes, while also offering the added benefit of zero-emission operation. But these units are heavy and difficult to transport if recharging has to take place off site.

Atlas Copco QHS 200 series Hybrid Tech gen set (Photo: Atlas Copco)

To address the downsides of oversized diesel gen sets and BESSs when operating tower cranes, Atlas Copco has introduced its new Integrated Hybrid Generator range. These are all-in-one gen sets which combine battery technology with a diesel engine under a single canopy.

When being used to power a tower crane, the onboard batteries are designed to deliver the power needed for short, intense activity. The diesel engine is used to recharge the batteries, eliminating the need for off-site recharging. The engine is also used to recharge the battery packs.

Supplying power to the battery pack allows the engine to operate at constant level of peak efficiency. While reducing related emissions, this also eliminates wet stacking, where an engine operating at a consistently low load fails to reach the optimal operating temperature, which can lead to performance-impacting carbon deposits and possibly unburned fuel in the exhaust.

Reduced emissions and cost

Developed by Atlas Copco’s Portable Power and Flow division, which is based near Zaragoza, Spain, the Integrated Hybrid gen sets bring together an engine supplied by FPT Industrial with lithium-ion phosphate (LiFePO4) battery pack with 60 kWh of storage.

Tower crane power demonstration at the media launch of the new QHS-series gen sets (Photo: KHL Group)

According to the company, compared with conventional diesel-only operation, the new gen sets can deliver fuel savings of up to 80%, while reducing CO2 emissions by the same number. Further, engine run time can be cut by up to 95%, lowering operating costs while helping to achieve sustainability targets.

The company stated that if the estimated 200,000 existing 200 kVA or lower diesel gen sets now in operation across Europe were replaced with hybrid variants, it could save 3.2 billion litres of diesel fuel each year.

While more expensive than a standard diesel gen set, Atlas Copco put forward that the potential fuel savings would help to bring an equivalency to total cost of ownership. The battery packs also help reduce TCO by reducing overall engine operation and so extending service intervals.

Model lineup

Three versions of the gen set will be available from launch: the QHS 120 S5, the QHS 200 S5 and the QHS 250 T4f. Power output ranges from 120 to 250 kVA.

Operation of each of these is managed by the ECO Controller, which balances power output as required from either the engine or battery pack. In the case of the QHS 120 S5, the 120 kVA peak output is achieved using the two sources in parallel.

In addition, the ECO Controller includes a battery state of health check to provide insight into battery management which can also help to improve system longevity.

The engine supplied by FPT Industrial is compliant with Stage 5 emissions standards. At launch, Atlas Copco noted that versions of the hybrid gen set using a Stage 3 engine would be ready for the Middle East and Australian markets in the coming years.