The Challenge
Project Background
Our client required a reliable and resilient temporary power solution to operate multiple tower cranes on a construction site. Traditionally, large-capacity diesel generators were used to accommodate high motor-starting loads associated with tower crane operations. While effective, this approach resulted in high fuel consumption, elevated carbon emissions, and extended generator runtimes.
The challenge was to maintain operational performance while reducing fuel usage, emissions, and unnecessary generator operation, particularly outside standard working hours.
Original Power Solution
The original setup consisted of:
- 2 × large-capacity diesel generators
- Each generator supplied power via an integrated fuel tank and intermediary distribution board
- Designed to handle high crane start-up loads
- Operated for approximately 50 hours per week
Performance Characteristics
- High fuel consumption due to oversized generators running at low efficiency during normal crane operation
- Continuous running required to support both crane operation and aviation lighting
- Elevated carbon emissions resulting from sustained fuel usage
This configuration, while reliable, was inefficient from both a fuel and environmental perspective.
Our Solution
Optimised Hybrid Power Solution
To address these challenges, the original generators were replaced with:
- 2 × smaller-capacity generators
- Integrated with Punch Flybrid hybrid energy storage units
The Punch Flybrid system is specifically engineered for high motor-starting applications, including:
- Tower cranes
- Construction hoists
- Recycling equipment
- Medical imaging systems (e.g. MRI scanners)
The Flybrid units manage short-duration peak loads during crane start-up, allowing the generators to be sized for true running load rather than peak demand.
Key Technical Improvements
- Generator size reduced by 50%
- Fuel consumption reduced by approximately 50%
- Improved generator loading and operating efficiency
- Lower emissions without compromising crane performance
Fuel and Carbon Reduction Outcomes
Fuel Consumption
- Weekly fuel usage per machine reduced by half
- Significant cumulative fuel savings achieved over the 21month hire period
Carbon Emissions
- Carbon emissions reduced from approximately 26 tonnes per month with the original configuration to approximately 12.4 tonnes per month with the hybrid solution
- Achieved a carbon reduction of more than 50% during crane operations
This reduction aligned with broader sustainability goals and supported compliance with evolving environmental expectations within the construction sector.
Out of Hours Energy Optimisation
To further enhance efficiency, an additional solution was introduced to eliminate unnecessary generator runtime outside working hours.
Battery Power Integration
- A 5/15kW Husspod battery unit was deployed
- Supplied power to:
- Crane aviation lighting
- Crane cab heater
Operating Schedule
- Powered cranes during non-working hours (6:00pm – 7:30am)
- Allowed generators to be completely shut down overnight
Benefits Achieved
- Further fuel and carbon savings
- Reduced engine wear and maintenance requirements
- Improved site noise reduction
- Enhanced environmental performance
The Results
- Generator capacity reduced without affecting performance
- Fuel consumption reduced by approximately 50%
- Carbon emissions reduced by over 50%
- Extended generator lifespan through reduced runtime
- Improved sustainability credentials across a long-term project
- Reliable power supply maintained throughout a 21month hire period
In Summary
By adopting a hybrid generator and battery-supported power strategy, our client successfully transitioned from a traditional high-consumption model to a more efficient, lower-carbon solution. The use of Punch Flybrid technology allowed for smaller generators, improved efficiency, and substantial environmental benefits over the project lifecycle.