How to achieve compressed air energy savings
With a price on carbon set, reducing energy costs has become even more important. GILBERT MCLEAN, national key account manager of the AirAudit division at CompAir Australasia, shares how energy savings of up to 50 percent can be made within a compressed air system.
The Clean Energy Bill 2011 has placed new impetus on businesses to find ways to reduce their carbon emissions. The alternative is facing a hefty rise in energy costs.
A price on carbon was set on 1 July 2012 by the federal government. The impact will not only be felt by the biggest polluters – companies in the waste disposal sector, cement, chemicals and metal processing industries. The largest group of polluters to be affected by this bill will be energy providers themselves – gas, electricity and coal retailers. Undoubtedly, they will pass some of this extra cost onto end users, meaning, directly or indirectly, the carbon price will affect every business in Australia.
Partly as a result of the carbon price, The Australian Energy Market Commission forecasts that nationally, nominal electricity prices will increase by 37 percent between 2011 and 2014.
FIRST STEP TO REDUCING ENERGY COSTS: A COMPREHENSIVE AUDIT
Compressed air represents one of the greatest opportunities within a business to generate energy savings and reduce the associated carbon footprint. A compressed air system is one of the largest consumers of energy in any business, with energy costs accounting for approximately 80 percent of the lifetime costs of a compressor.
The first step in reducing compressed air associated energy costs is to undergo a comprehensive audit. Such an audit should identify areas of loss or inefficiencies within a compressed air system that meets the requirements of the Australian Federal Government’s Energy Efficiency Opportunity Act, in conjunction with the National Greenhouse and Energy Reporting (NGERS) Act.
A ‘total systems integration approach’ that includes leak detection, demand- and supply- side flow analysis (end use), full measurement of power absorbed including power factor, actual flow rates and, where relevant, pressure and dew point is advisable.
The result should be detailed independent reports and analysis of a compressed air system that includes recommendations for leak correction, leak tracking (data management for repeat surveys), targeting of maintenance upgrades, flow demand characterisation and optimisation, a compressed air distribution summary, a comprehensive list of compressed air solutions, a risk assessment and a cost savings summary. Additionally, a plan for ongoing energy cost reductions is desirable.
HOW TO ACHIEVE COMPRESSED AIR ENERGY SAVINGS
An audit can identify savings that can be created on both the demand and supply side of a compressed air system.
10 to 20 percent of energy savings can be found on the supply side by improving;
- Compressed air equipment: Changes in shift patterns or production will change the demand for compressed air. It may be the case that upgrading the compressor to better meet these new demands will reduce the associated energy costs.
- Compressor technology: Where appropriate replacing a fixed speed compressor with a variable speed compressor will reduce energy costs. Variable speed technology matches output to exact requirements minimising off-load running.
- Control and monitoring: Implementing an energy management system will ensure a compressed air system can be controlled and monitored on an on-going basis for optimised energy usage.
- Maintenance: Following the recommended manufacturers maintenance schedule will ensure minimal wear and tear of consumable parts optimising system efficiency.
Additionally, up to 50 percent energy savings can be achieved by following the recommendations from an audit’s detailed demand side analysis, which will identify areas of improvement in artificial demand, system dynamics, compressed air leak detection and system design, as well as monitoring and sub-monitoring.
ATTAINING FEDERAL FUNDING
The cost of undergoing an audit can be easily and quickly recovered through reduced system costs. Depending on a facility’s location and business type, the cost of the audit and the work to improve and optimise your compressed air system may even be covered by state or federal government funding.
If applying for funding under the Australian Federal Government’s Clean Technology Investment Program or the Clean Technology Food and Foundries Investment Program, an audit will provide necessary support for the application to upgrade plant and equipment.
By identifying improvements in a compressed air system through an audit and acting on these, it is possible to reduce power consumption and thereby reduce your associated energy costs. In turn compressed air system load will be reduced, as well as wear and tear, which will extend the life of the compressed air system and deliver a greater return on investment.