There are several benefits for manufacturers to invest in energy-efficient processes and technologies, including:
- reduced costs
- improved productivity
- increased predictable earnings
- reduced carbon emissions
- meeting corporate environment goals.
Manufacturers can also improve competitive advantage through designing and manufacturing energy-efficient products. This achieves greater product differentiation, market share and customer loyalty.
Significant energy savings can be gained through optimisation of existing equipment and upgrading where possible. Improving real-time process data-monitoring and benchmarking will support this process.
Some examples of energy-efficiency opportunities are outlined below.
Operating temperatures and pressures
Manufacturing equipment operates at varying temperatures and pressures. Ensuring all equipment is operating at optimal settings saves energy.
Assess pressure requirements of the plant. Identify where you can reduce energy use without affecting core processes.
Operate air compressors at the lowest required pressure settings to reduce energy use for that equipment by up to 10%.
Review air-conditioner or cool-room settings and widen the temperature band where feasible to reduce:
- energy consumption
- loads on refrigeration plant
- the possibility of equipment failure.
Other opportunities include:
- operating extraction fans only when equipment is in use
- providing make-up air close to the equipment
- ensuring the make-up air inlet is closed when equipment is not in use.
Many manufacturing plants have equipment running when it’s not in operation.
Install timers to turn machinery and equipment off or to idle setting. This can be done easily for appliances such as air compressors and air conditioners, as well as lighting.
Be sure to fix or replace temperamental equipment so that everything can be turned off and on regularly without the risk of not restarting.
Identify and insulate equipment that continually loses or gains heat when not delivering useful services.
There are many ways to improve the efficiency of lighting equipment in manufacturing plants, such as:
- manual or automated control of lights
- increased levels of natural daylight
- installation of LEDs or induction alternatives to ageing fluorescent and high-bay lights.
To read more, see the Lighting guide.
Individual HVAC unit components, such as motors, can be replaced with high-efficiency versions. There are also ways to generate energy savings from existing HVAC systems, including:
- passive solar design techniques to heat and cool air-conditioned spaces
- improved building insulation
- high-performance glazing, external window shading and proper window coverings
- reflective cool roofs
- minimising air leakage through the building envelope
- operating the system only when and where needed, using timers and individual zone control.
To read more, see the HVAC guide.
A motor system includes the motor itself, the components it drives (pumps, fans and air compressors) and its controls. Best practice motor management considers how these work together and can deliver significant energy savings.
Approximately 5% of a motor’s lifetime cost is for purchase, installation and maintenance. The remaining 95% is for the energy used, meaning the purchase cost of a premium energy-efficient model will be paid back many times over on energy savings alone.
Premium motors also have indirect cost-savings through longer bearing life, insulation life and less vibration. They also run cooler, reducing the plant cooling load.
The use of variable speed drives combined with high-efficiency motors and improved motor system management can also unlock energy savings.
See the Energy Rating website for a searchable database of electric motors with information on energy efficiency.
To read more, see the Motors and variable speed drives guide.
When compressed air load has been reduced and leaks in the distribution network have been repaired, a correctly sized compressor can be installed to increase energy efficiency.
Air compressors are most efficient when near full load. As a result, the best air compressors are sized correctly for the application. If the load is unavoidably variable, a combination of smaller compressors and variable speed drives may meet the load more efficiently. One compressor can meet the baseload, with the others coming online to meet peak loads.
Types of compressors include:
- rotary tooth.
While each type has its advantages and disadvantages, reciprocating and centrifugal compressors are generally the most efficient.
Peak loads can also be reduced by using storage receivers, which can store 5% to 10% of compressor capacity.
To read more, see the Compressed air guide.
Modern boilers are a good investment as they don’t waste energy by unnecessarily turning on to recover standing losses during non-operation. They avoid this form of energy waste with:
- timing controls
- performance monitoring systems
Further efficiencies can be achieved by investing in solar water heating systems. To save energy, these systems preheat boiler feed water up to 80ºC. This suits a wide range of food and beverage processing plants.
To read more, see the Process heat and steam guide.
Heat loss minimisation
Investing in insulation for roofs, walls, boilers and pipe-work can minimise heat loss and yield energy savings. It also has significant co-benefits through reducing heating and cooling loads.
Try to limit losses from boiler systems by insulating valves, steam and condensate return pipes, and storage units.
There are heat recovery opportunities in many manufacturing sectors. Those sectors with high-temperature processes or steam generation and boilers are especially suited to heat recovery.
Co-generation systems use heat, steam or waste gases to produce both electrical and thermal energy. Tri-generation (producing cooling as well as electricity and heat) can suit some sites.
Co and tri-generation systems are ideally suited to manufacturing plants. That’s because they produce the most energy when plants are running at close to 100% capacity.
Most systems are found in energy-intensive manufacturing sectors. Developments in small-scale co-generation, such as micro-turbines and fuel cells, are also opening up opportunities.
Innovations in heat exchangers have enabled heat recovery from processes that were previously too extreme due to high temperatures, high pressure or hazardous chemicals. This has been made possible through the use of new materials that are resistant to corrosion or can tolerate higher temperatures and pressures
To read more, see the Waste heat recovery guide.
Process integration saves energy costs in manufacturing plants with multiple heating and cooling demands. Linking hot and cold processes can reduce heat losses and identify heat recovery opportunities.
Pinch analysis helps to do this. It can identify and correct the ‘pinch’ (performance limiting constraint) in a manufacturing plant by using two composite curves—one for heating and one for cooling.
Plotting the two curves on a temperature-enthalpy graph reveals the pinch and corresponding energy targets (minimum feasible energy use for heating and cooling). Heat exchanger networks can then be designed to link processes to meet these targets.
Pinch analyses can be conducted on both new and existing plants.
Take a collaborative approach to energy and carbon management within the supply chain. Helping participants to better coordinate can improve the whole production process and bring large savings.
Supply chain management also addresses customer expectations around sustainability and helps maintain a competitive edge.
Strategies may include engagement with suppliers to encourage energy-efficiency investment and changing purchasing policies to favour lower embodied-energy materials.
The Australian Renewable Energy Agency (ARENA) Renewable Energy Options for Industrial Process Heat report outlines opportunities to switch to renewable alternatives to provide process heat. The report shows shifting to renewables is possible through a variety of technologies, including
- solar thermal.
To read more, see the Renewable energy guide.
High-temperature insulation is increasingly being used in manufacturing applications, including for processes that reach in excess of 1000°C.
Materials used in these applications include alumino-silica and mullite ceramic fibres, calcium silicate, and mineral wool fibres. Such materials are available in numerous grades, compositions and consistencies, all of which can affect maximum insulating capacity.
Advanced ways to generate high-temperature fluids and steam are also showing promise, such as the use of solar thermal and heat-pump technologies. Other process innovations include the use of microwave kilns and dryers, and component manufacture using 3D printing.
Improved processes in composite fibres and light metals are making it possible for transport vehicles to be significantly lighter, saving more energy.
Due to the rise of efficient electrical technologies such as high temperature heat pumps, high performance motors, and microwaves, many production facilities can now largely run on electricity. This offers a number of advantages that include:
- less reliance on fossil fuels such as gas
- better control and integration of processes and equipment
- more flexible demand management and electricity tariff selection
- more reliable and productive operation
- opportunity for onsite solar PV which reduces energy costs and emissions, enhances energy security and improves environmental reputation.
The trend towards electrification, digitalisation and automation in industry is enabling the transition to advanced manufacturing and industry 4.0. Advanced manufacturing has the potential to enhance competitiveness and can address common industry challenges such as high labour costs and distance to markets.
The Australian Government provides funding to help Australian manufacturers grow, innovate and compete.
To read more about how automation and digitalisation can drive business efficiency and productivity, see the Industry 4.0 guide.
Advanced Manufacturing Growth Centre
The Advanced Manufacturing Growth Centre (AMGC) is an industry-led, not-for-profit organisation established in 2015 as a key plank of the Australian Government’s Industry Growth Centre Initiative. Its goal is to drive innovation, productivity and competitiveness across Australia’s manufacturing industry.
The AMGC engages with manufacturers and universities in high-impact projects and export hub opportunities on how the industry can transform to become more advanced.
AMGC membership is open and free of charge, with likeminded manufacturers and research institutions encouraged to join. See the AMGC website to become a member.
Energy sustainability for Queensland manufacturers
The Queensland Government’s Energy sustainability for Queensland manufacturers website provides insights and research to assist Queensland manufacturers manage their energy needs.
The website includes:
- a checklist to assess the energy efficiency of your business and what you can do to improve
- how to understand the structure of your electricity bill
- case studies showing how other Queensland manufacturers are becoming more energy efficient.
Clean Energy Finance Corporation (CEFC) Australian Government - Energy efficiency, sustainability and renewable energy projects at a variety of operations.
ecoBiz Queensland Queensland Government - Manufacturers investing in processes to make their businesses more sustainable, including a foundry and textile manufacturer.
Energy Efficiency Information Grants Australian Government - Energy assessment outcomes and equipment upgrades.
Energy sustainability for Queensland manufacturers Queensland Government - Projects covering various focus areas including demand management, variable speed control, HVAC and solar.
Sustainability Victoria Victorian Government - Manufacturers and businesses in other industries that have lowered their energy consumption, reduced emissions and saved money.
Australian Manufacturing Gas Efficiency Guide (PDF 2.51 MB) (CEFC) Australian Government
Navigating a dynamic energy landscape: A briefing for manufacturers Energy Efficiency Council