Energy management is structurally driven when all key areas are considered. The key areas are Commissioning, Energy audit and Building Re-tuning. Here let us see about Energy Audit….
An energy audit is an inspection, survey and analysis of energy flows, for energy conservation in a building, process or system to reduce the amount of energy input into the system without negatively affecting the output(s). In commercial and industrial real estate, an energy audit is the first step in identifying opportunities to reduce energy expense and carbon footprints.
Rising and fluctuating energy prices are a strong motivator of change for facility managers. Limited operating budgets make price shocks tough to absorb, and trying to predict what prices will be doing next year can be an exercise in futility. If you pay real-time prices this is a daily challenge, but even if you have a utility rate contract you’ll have to face the issue when it’s time to renew.
Reducing your energy use through improved efficiency is a well-known strategy for reducing energy costs and managing energy cost risk. It also has impressive sustainability benefits because of reduced fuel consumption and emissions. Let’s say you’re on top of this and have already benchmarked your building and determined that it’s not performing as well as its peers. Let’s also say your organization has already decided to make a concerted effort to reduce your energy costs. Now you need to determine which specific things need to be done to make your building perform better.
What you need is formal energy audits of your facility. There are opportunities to bring energy efficiency everywhere. On the supply side, more efficient generation and distribution, as well as cleaner energy sources. On the demand side, in every segment there are technologies that can be applied today to increase efficiency and reduce cost. And in the middle there are programs to more effectively coordinate supply and demand. Today we will see how energy audits help determines priorities with good return on investment in the second and third of those areas.
The Energy Efficiency Cycle
Energy efficiency needs a structured and persistent approach. Through an energy audit you will find many opportunities to bring energy efficiency to your organization. But it’s important to recognize that you won’t fully optimize your results unless you also automate and regulate the consumption. Monitoring is the key to maintaining the savings.
An Energy Management Program should follow this cycle and an Energy Audit is a great way to start.
Energy audits are comprehensive evaluations of the actual performance of a facility’s:
- Energy using systems and equipment—compared against the designed performance level or the industry best practice, and
- Energy-managing systems
The purpose of this write up is to review the different types of energy audits; as well as the overall auditing process in order to successfully prepare and participate in the energy audit process.
Let’s begin with a discussion of what energy audits tell us.
An Energy Audit should tell you three things: It will tell you about your current energy consumption. It will tell you about your potential to save energy. And it will help you to prioritize your actions. Let’s look at each in turn. The energy audit should give you clear visibility on energy consumption and cost. This means it should provide you with a simple, comprehensive overview of all the types of energy that you are using, and their cost. It should also break out the energy consumption by users so that you know where and when the energy is being used. Secondly, it should identify your energy conservation opportunities. It does this by telling you how energy is used and wasted, and describing the energy saving alternatives that could be adopted. Thirdly, the audit will also provide an energy management plan including recommendations with cost-benefit analysis as well as prioritization of best practices, quick wins and easily implemented solutions.
Common Audit Opportunities
Throughout your facility there could be many opportunities for energy savings. Typical audits uncover deficiencies in Energy Consuming Systems, such as:
- Compressed Air
- 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 can be the largest energy wasters. Other areas that have an influence on energy use will also be evaluated, including:
- Operations and maintenance as well as
- Employee Awareness
Energy audits tell us that:
Low consumption devices and efficient installation can lead to energy efficiency gains of 10 to 15% of total consumption. This is what we call passive energy efficiency. Low consumption devices and efficient installation could be things like well insulated buildings, high efficiency motors, and more efficient lamps. Secondly, optimized usage of installation and devices will net a 5 to 15% increase in energy efficiency. For example: up to 40% of the potential savings for a motor system is realized by the drive and automation, and up to 30% of the potential savings in a building lighting system can be realized via the lighting control. Thirdly, a permanent monitoring and maintenance program will garner efficiency of an additional 2 to 8%. This would require you to implement continuous measurement and to react in case of deviations. Automation and permanent monitoring are examples of active energy efficiency.
Energy Audits also tell us that savings can be quickly lost due to various factors. Unplanned, unmanaged shutdowns of equipment and processes can be costly in terms of energy.
Additionally, a lack of automation and regulation of areas such as motors and heating can lose up to 12% per year Lastly, without a monitoring and maintenance program to preserve continuity of behaviors, up to 8% per year is lost.
Let’s move on and discuss the different types of Energy Audits.
The first type of audit we will examine is a Walkthrough. A walkthrough is a light audit that consists of a relatively brief inspection of the facility to identify maintenance, operational or deficient equipment issues and to identify areas which need further evaluation. Some quick-wins can be identified and some estimated financial calculations can be done at this step.
Another, more detailed type of audit is the Comprehensive audit. This would be a thorough audit, evaluating the energy consuming systems of the building or plant in detail. It may include performing specific monitoring, metering or testing to identify actual energy consumption and losses. It will also include an economic evaluation of the identified opportunities, including cost and benefit.
Comprehensive audits may be enhanced by including more detailed refinements. Examples would include: Computer modeling to determine the year round energy consumption and/or savings. Additional financial analysis to support investment decisions. This would also include evaluating risks within the economic calculations. This type of audit may be needed to obtain funding for the projects identified–and is sometimes known as “investment grade audit”.
Information such as code compliance, maintenance schedule development, and equipment inventories.
Determining Which Audit to Select
So which type of energy audit is best for you? That answer is dependent on many different factors, including:
- Funding available for the audit
- Cost and potential of the Energy Conservation Opportunity (ECO)
- Required accuracy for the audit information
- Type of facility
- Function of facility
- Processes within the facility
Energy audits can be self-assessments conducted by company staff, external audits obtained through energy service professionals, or a combination of both. Regardless of the type of audit, it is recommended that the audit team represent varied expertise, including: process engineers, maintenance experts, systems managers, energy specialists, etcetera. Support from outside your company can be extremely helpful and provide an external point of view for the site as well as professional expertise in many areas.
An auditor basically performs four activities. These activities include:
- Understanding the site and gathering the data
- Assessing the situation, and
- Proposing an action plan
Let’s explore each of these audit activities in more depth.
Understand the Site and Gather the Data
Successful auditors take steps to ensure that they understand the site and are able to gather the appropriate data. Employing well-written questionnaires and conducting site visits guarantees the auditor has a clear understanding of the operating conditions. Examples of items to review would be the process, including the identification of the main steps and energy requirements, the facilities and utilities such as compressors, HVAC, Electrical Network, Building Envelope, and so on. Additionally, the review will include the Building Management Systems—such as HVAC control and lighting control as well as the energy awareness and behavior of the people at the site.
The second activity involves measuring, monitoring, and testing. In order to successfully perform this activity, the auditor will need to perform a variety of tests, for example, to verify that a sensor is working correctly. These tests provide key data about the equipment or information to show if certain types of improvements are feasible. Additionally, if pre-existing data is not available or not sufficient, the auditor may also need to measure and monitor the energy profile and load in order to identify energy losses. 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. It could range from snapshot measurement or a test for a walkthrough up to detailed measurement and test including monitoring over a significant period for the comprehensive type of audit.
Larger buildings and factories contain complex systems. Optimizing the performance of systems such as variable air volume HVAC systems requires continuous monitoring and control adjustments. Therefore, large sites and complex systems must be evaluated and treated as a dynamic, not static user of energy. The measuring and monitoring period must take account of this.
Assess the Situation
In the third activity, the auditor will assess the situation. This is done by: Checking and analyzing all of the data collected. Looking for Energy Conservation Opportunities—which may also involve conducting a study of their feasibility, as well as Performing cost-benefit calculations.
Propose an Action Plan
Finally, the auditor will propose an action plan. The output of the audit is the proposed action plan. An action plan will:
- Provide ways to manage and control power consumption and costs, as well as
- Propose energy savings solutions
Preparing for the Energy Audit
The key to performing these activities successfully is being thoroughly prepared, so let’s spend some time addressing what is involved in preparing for the audit.
There are two areas to focus on when preparing for an energy audit:
- Commonly required data
- Planning the audit activities to include participation of the necessary people from the facility
Let’s look at the data requirements first.
Commonly required data will encompass things like company background. The company background would include knowing the company’s perspective on energy efficiency: the organization’s energy goals and financial rules—for example; minimum payback periods required for actions. The auditor will also need information on energies/fluids consumption examples of relevant “fluids” are fuel oil or water and this information will be found in the bills from energy suppliers—both monthly and annual bills—as well as in the energy tariff details.
At least 24 months of consumption should be evaluated for each energy source. Be sure to provide the auditor with a copy of the site layout—including a layout with dimensions indicating the location of different processes and energy utility rooms.
Additional data to gather for the audit includes a site operating profile. This is based on the load profile of the site, which analyzes the consumption daily, weekly, monthly and annually to identify the patterns. This is coupled with the facility operating profile, which describes how the site is used. For example, is the site normally open during only office hours, or also at other times? For an industrial site, how many shifts are running each day, do they work at 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. It’s important to provide information about specific equipment as well as the site as a whole. An equipment inventory supported by data on the equipment characteristics helps the auditor to understand the site and plan where to spend time during the audit. For major pieces of equipment, the operating hours and load profile (if available) will be useful to understand the consumption at a more detailed level, and start to identify potential opportunities.
Where might all this information be found? Here are some possibilities to investigate:
Data from energy suppliers—such as tariff structure, or machine suppliers—such as pump characteristic curves
- Data from facility specification documents—such as site layout, chilled-water distribution schema, etcetera.
- Data from the operating schedule and utilization or occupancy data of the plant for correlation with the energy consumption.
- Manually collected data—for example—from meters or extracted from other systems (Monthly electricity consumption, production quantities, and etcetera).
- Facilities may capture this type of information in a spreadsheet program or database (such as Microsoft© Excel or Access).
- Temporary meters may be used to record values that are not normally monitored but that are useful specifically for the audit analysis, and finally
- Historical data recorded in the Energy Management System—this will encompass things like the loading profile, the power factor, the energy curve, and the temperature curve
The data will be more accurate, and hence more accurate audit results, if they are
- Recorded over a long period, and involve
- Real-time monitoring data
The data will be more helpful if they are in an “easy-to-be analyzed” format such as a spreadsheet or graphic curve. 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 key facts should be reviewed by the auditor in order to plan the audit approach—for example, who is involved, how much time will be needed, etcetera. The full set of data should be prepared for the audit days, since these documents are essential to understand the site and spend less time on data gathering and more time on site evaluation.
As well as preparing the data for the audit, the audit activities have to be planned, including participation of people from the site who have valuable perspectives. Let’s move on and describe different components for an energy audit.
Energy Audit: Main Steps
The energy audit commonly includes four distinctive components, (and this is especially true if the audit is performed by external company):
Let’s explore each of these audit components in more depth.
Kick-Off Meeting Typically the walkthrough or audit begins with a “kick-off meeting”. In this meeting it’s a good opportunity to have all of the people that are involved around the table. This would normally include the facility manager, energy manager, maintenance supervisor, and the internal or external auditors. Depending on the scope of the audit and the structure of the organization, it might also include the production manager, financial department manager, or other roles. During this meeting, take the time to explain the audit purposes, review the global plan for the audit and go into more details on task plans. It is also during this meeting that you will provide the auditor with the information that has been prepared, as well as giving them the opportunity to ask for more information about processes, energy, and the modernization plan for the facility.
On-Site Inspection After the kick-off meeting, the on-site inspection will start. This step consists of making visits to the workshop, substation, warehouse, and offices to understand the process and how energy is consumed. The maintenance technician responsible for the area being visited should accompany the auditor throughout that part of the audit. The auditor may also have questions for the maintenance supervisor, equipment/area operators and other facility staff to understand the building and the process operation performance problems. Those questions can normally be answered by short interviews, although complex discussions may take longer. A key success factor while planning the audit is to ensure the necessary people are aware of the audit and available on the day. The auditor will also take measurements during the visits — these measurements may be snapshot measures, or the auditor may leave a temporary meter in place for a few hours or days to record data if required. The on-site inspection should be closed by a wrap-up meeting with the same attendees as the kick-off meeting to announce the first results of the inspection as well as making a final agreement on the deliverable content and a restitution date.
The next component is data analysis. This step consists of:
- Performing engineering calculations
- Running simulations and tools if necessary
- Contacting solution suppliers to find the cost of the solution and then performing cost-benefit calculations, and
- Writing the deliverables–this will include a presentation and/or report
The results restitution is the output of an energy audit. The restitution supports are commonly a written report. The report should be adapted to the audience. The readers can range from the company president to the head of maintenance. Using a simple, direct writing style will ensure the report is clear, understandable and readable.
Every audit will culminate with an audit report. At a minimum, the report should include:
- Executive Summary
- Energy Cost Analysis
- Energy Management Recommendations, and a Proposition of Energy Action Plan
Let’s discuss each of these in more detail.
The executive summary is the first thing the reader will see and it will set the tone for the rest of the report. The summary should be short, concise and to the point. The executive summary will also list the recommended energy conservation measures and shows the implementation cost as well as financial savings amount. This section is intended for readers who only want to see the bottom line.
Energy Cost Analysis
Your report will also provide information on the operation of the facility that relates to its energy costs. This could include:
- Energy bill analysis–such as comments on charges and penalties
- Energy consumption break-out, as well as the
- Demand curve
The recommendations section lists the areas that were evaluated in the scope of the audit, and contains a discussion of each of the energy management opportunities that have been determined to be cost effective, and aligned with the financial evaluation criteria collected before the audit. Each energy management recommendation addressed in the executive summary will be described in-depth in this section. Each recommendation should summarize the energy demand and cost savings, the implementation cost and the return on investment using the customer’s financial criteria. Frequently, a simple payback period is used to evaluate ROI. There should also be a brief narrative detailing the background information regarding the recommended action and an explanation of how it should be implemented at the facility.
For each recommendation, the method used to arrive at the savings estimate should be referenced or explained here.
Energy Action Plan
The report should suggest an Energy Action Plan. This plan will detail the recommended actions and the implementation schedule. Quick-wins and short pay backs should be implemented first, so savings can be generated rapidly and provide money to pay for high investment solutions. The plan will also propose a monitoring system for following up on the performance and for driving continual improvement.
The audit is the first step for starting an Energy Management Program. Follow-up actions are necessary to benefit from the audits and drive continuous improvements for the site. These follow-up actions will require you to:
- Validate the energy action plan and the implementation schedule
- Define the energy saving goals
- Implement the action plan
- Establish indicators for measuring the fulfillment of the goals
- Set a baseline and compare the performance over time, as well as
- Seek additional opportunities for continuous improvement
Today, we understand about the information obtained by performing an energy audit: which includes details of current energy consumption, potential to save energy and particulars to help to prioritize actions. We saw that in many industrial facilities, the largest energy wasters are failed steam traps and compressed air leaks, while in commercial buildings, HVAC systems and lighting can be the problem areas. We looked at the difference between a walkthrough and a comprehensive audit.
We saw the four main activities performed by an auditor:
- Understanding site and gathering data
- Measuring and testing
- Assessing the situation
- Proposing an action plan
Since larger buildings and factories contain complex systems, they must be evaluated and treated as dynamic, not static users of energy. The measuring and monitoring period must take account of this. Typically at least 24 months of consumption should be evaluated for each energy source.
We also reviewed the two main ways a customer can help make an audit successful:
- By preparing relevant information
- By ensuring access to the right people
Finally, we understand the key four steps of an audit:
- On-site inspection
- Data analysis
If you’re serious about saving as much energy cost as possible with the quickest payback time and least hassle,take the time to plan your energy projects right. Perform a good energy audit, and assess its results carefully based on the needs of your facility, whether based on annual savings, initial cost, payback time, and synergistic comfort benefits to occupants, or recurring maintenance hassle. The rewards are well worth the work.