Energy management programs have proven successful in reducing commercial and factory building operational costs. Efficient Installation of low consumption devices alone (like motor systems with variable speed drives or controlled lighting) can lead to energy efficiency gains of 10 to 15%. Managed usage of these devices can net an additional 5 to 15% increase in energy efficiency. The third element in the equation, a permanent monitoring and maintenance program, can contribute additional efficiency improvements of 2 to 8%.
The first step to cashing in on all of these efficiency gains is to conduct an energy audit. A successful energy audit will provide the following:
- Current energy consumption levels – The audit identifies the types of energy being consumed and their cost. Energy consumption data is broken down by user so that sources of high energy usage are located.
- Potential for energy savings – Areas of energy waste are identified, and both energy conservation opportunities (process corrections) and energy saving alternatives (hardware and software solutions) are proposed.
- Guidance for prioritization of actions – An energy management plan is formulated which includes recommendations, a cost-benefit analysis, prioritization of best practices, and identification of quick wins.
Typical audits uncover deficiencies in energy consuming systems, such as pumps, ventilation, lighting, compressed air, steam, refrigeration, HVAC, and process machinery. In many industrial facilities, the largest energy wasters are failed steam traps and compressed air leaks. In commercial buildings, HVAC systems and lighting are often the main culprits.
The length, frequency and the number of points to be measured or tested can vary depending on the type of audit and the application to be investigated. The audit can range from a snapshot measurement, to a walkthrough, to detailed measurement and monitoring over a significant period of time.
A successful audit requires advanced preparation
When preparing for an energy audit, the auditor should acquire and evaluate the target organization’s energy goals and financial parameters (such as minimum payback periods required for actions). The auditor also requires information on energy and fluid consumption (e.g., water, oil). This information can be extracted from utility services supplier bills—both monthly and annual bills—as well as from energy tariffing details. At least 24 months of consumption information should be evaluated and recorded for each energy source.
The auditor also requires a copy of the site layout—including the location of energy utility rooms and other key energy distribution hubs. A site operating profile should also be generated. This is based on the load profile of the site, which analyzes the consumption daily, weekly, monthly and annually to identify use patterns. For example, is the site normally open during only office hours, or also at other times? Within an industrial site, how many shifts are running each day, do they work on the weekend, and do some shifts use fewer production lines than others? This information allows the auditor to analyze rate options, such as time-of-use tariffs that may help reduce the energy cost.
The key to success is to have the maximum amount of data prepared and ready before the audit takes place, especially if the audit is conducted by an external company or expert.
The audit is the first step for initiating an energy management program. Follow-up actions are necessary to benefit from the audits and drive continuous improvements for the site. To learn more, register for Schneider Electric’s FREE Energy University course on conducting energy audits.