Gold Coast Steel Manufacturer and Fabricator

A Gold Coast steel manufacturer could reduce its production facility’s annual energy costs and consumption through fit-for-purpose upgrades to lighting and improvements to its energy-intensive air compressors, with payback periods for the initial investments ranging from just 1 to 4 years. By expanding its solar photovoltaic (PV) installation, the manufacturer could also achieve greater energy independence and significantly reduce emissions.

Lighting

Though a lighting assessment, it was found that a combination of lighting upgrade solutions could reduce the manufacturer’s annual energy operating costs. These include:

• Redesign of the lighting layout and replacement of the remaining 525-watt mercury vapour high bay lights with LED lights. This project would lower energy consumption by 112,500 kilowatt hour (kWh) each year, saving the manufacturer $18,831 in annual energy costs.
• An automatic method to turn off lights during bright daylight hours would reduce energy wastage and unnecessary costs. With a capital investment of $3,000 and payback period of just 1.7 years, this would save over $1,700 in operating costs each year.

Air Compressors

As a major contributor to the site’s electrical load, the air compressor system (three air compressors - one operating as baseload, two in a lead-lag arrangement) should be a target for efficiency improvements.

A new variable speed compressor is recommended, at a cost of $41,000 and payback period of 4.2 years, to replace an existing compressor. This recommendation is based on:

• Improvements in air compressor technology, which will improve the efficiency of the air flow and power draw.
• The affordability of variable speed drive systems.

The new compressor would be used as the ‘trim’ machine, to vary air output as required. The compressors would need to be sequenced correctly to realise the full 58,000 kWh in energy savings.

Based on the findings of the site assessment, the following is also recommended:

• Conduct regular compressed air leak surveys using an ultrasonic detection device to promptly repair any leaks.
• Where required, remove compressed air usage and replace it with electrical tools. A compressed air usage review would identify its inappropriate uses and recommend replacement options.
• Replace the large bore pipework near the compressors, characterised by 90-degree bends, with purpose-designed compressed air reticulation to limit the pressure drops that currently lead to a higher pressure set point, and therefore use more energy.

Solar

The manufacturer largely relies on electrical energy to power its facilities. Sourcing renewable energy is key to the decarbonisation of its energy consumption. To complement its existing 99 kilowatt (kW) solar system, a suitable section of roof that would be ideal for a 200 kW peak solar PV system has been identified.  This would provide over 90% of the site’s load during peak solar energy production and deliver the manufacturer greater energy independence, while reducing carbon emissions.