Case Study
Shopping centre benefits from 30 per cent water and energy savings
Problem
High water and energy use was resulting in significant monthly bills for an Indonesian shopping mall.
Solution
The introduction of Optidrive Ecos with Optiflow technology has helped reduce water use and cut energy costs by 30 per cent as a result.
Karawaci Shopping Mall
A major shopping centre near Jakarta, Indonesia is achieving at least 30 per cent savings in water and energy costs as a result of installing Invertek Drives Ltd’s Optidrive Eco variable frequency drives (VFD).
The monthly water and associated energy costs at the Karawaci Shopping Mall, West Jakarta amounted to over £350,000, the single largest cost facing the retail site.
Water was being pumped throughout the four-storey building daily using three of the four 15kW pumps located in the building’s car park on average, irrelevant of actual demand.
The mall’s owners wanted to reduce these costs significantly and through a local VFD distributor decided on the Optidrive Eco with Optiflow technology as the solution.
“There was no control over how much water was being pumped through the system compared to the actual demand. So, you had a system where at least three of the pumps were in constant use,” said Kes Beech, Technical Manager at Invertek Drives Ltd, one of the world’s leading designers and manufacturers of VFD technology.
“Four Optidrive Ecos were installed and commissioned in the system for each pump. With the use of Invertek’s Optiflow technology, each of the four pumps can be controlled independently depending on demand.
“This ensures only the optimum number of pumps are in operation. When demand falls some pumps can be put to sleep or their speed reduced. In the case of the shopping mall we have seen, on average, just two pumps required.”
Optiflow allows more than one drive working together to ensure an optimised flow. The first Optidrive Eco is the master and the other three are slaves. The master controls and commands the slaves with their speeds and run times.
The system is controlled intelligently based on demand using the internal PID function of the Eco drives. The system is never under stress mechanically, ensuring savings on any wear and tear or downtime.
The output pressure is continuously measured and sent to the master drive. The master then intelligently sets the on and off condition and speeds of all drives based on the internal PID and Optiflow functions.
“The system means you will see significant energy savings almost immediately. The master controls the pumps in the most optimum way and each Optidrive Eco drive operates their corresponding pumps with variable speed instead of a constant maximum. In some cases, it puts pumps to sleep when they are not required, such as overnight,” added Kes.
“In the case of the shopping mall, the peak periods were at weekends when the mall was at its busiest. This means at other times during the week the VFDs and Optiflow would reduce use and subsequent energy.”
This results in lower energy consumption and wear and tear, extending the life of the pumps.
The system is also never shut down as if a drive or pump is out of service, operation transfers to another. The drives also detect and clear pump blockages, provide dry run and burst pipe protection.
The result is an optimised water supply ensuring no wastage, reduced costs and optimised savings.
“The mall’s owners had hoped for 15 per cent savings, but since installing the drives in January it has benefited from 30 per cent savings,” said Kes.
