What is an Energy Audit?
An energy audit is a preliminary activity towards instituting energy efficiency programs in an establishment. It consists of activities that seek to identify conservation opportunities preliminary to the development of an energy savings program.

The Role of an Energy Audit
To institute the correct energy efficiency programs, you have to know first which areas in your establishment unnecessarily consume too much energy, e.g. which is the most cost-effective to improve. An energy audit identifies where energy is being consumed and assesses energy saving opportunities - so you get to save money where it counts the most. In the factory, doing an energy audit increases awareness of energy issues among plant personnel, making them more knowledgeable about proper practices that will make them more productive. An energy audit in effect gauges the energy efficiency of your plant against “best practices”. When used as a “baseline” for tracking yearly progress against targets, an energy audit becomes the best first step towards saving money in the production plant.

Contents of an Audit
An energy audit seeks to document things that are sometimes ignored in the plant, such as the energy being used on site per year, which processes use the energy, and the opportunities for savings. In so doing, it assesses the effectiveness of management structure for controlling energy use and implementing changes. The energy audit report establishes the needs for plant metering and monitoring, enabling the plant manager to institutionalize the practice and hence, save money for the years to come. The energy audit action plan lists the steps and sets the preliminary budget for the energy management program.

1. Analysis of energy use
Identifying where energy is used is useful because it identifies which areas the audit should focus on and raises awareness of energy use and cost. The results of the analysis can be used in the review of management structures and procedures for controlling energy use.

Analysis of energy use can be done by installing sub-meters in different plant locations to pinpoint actual energy usage per area. This is a good source data for allocating energy use. The plant manager can also list all equipment used and the corresponding operating hours. With this information, he can create spreadsheet information and generate charts useful for analysis.

2. Identification of energy projects
Opportunities for energy savings can range from the simplest, such as lighting retrofits, to the most complex such as the installation of a cogeneration plant. The important thing to remember is to focus on major energy users and areas. Always apply the 80/20 rule, focus on opportunities that provide 80% of the saving but require 20% input. After the preliminary identification of opportunities, spend more time on those which have shorter payback periods.

3. Cost benefit analysis
The identified energy conservation opportunities should be analyzed in terms of the costs of implementing the project versus the benefits that can be gained. If you want to, say, install a heat plate exchanger to recover waste heat, you need to calculate the total cost of installation and compare that with the savings you will derive from recovering waste heat. It makes sense to go on with the project if there is a net positive benefit from the project.

4. Action plan to set implementation priority
After passing the cost benefit test, an action plan should be developed to ensure that the opportunities identified are implemented. The action plan should include all the major steps for implementing the opportunity as well as the people responsible. Furthermore, there should be a plan for monitoring the results.

TYPES OF ENERGY AUDITS
The term energy audit is commonly used to describe a broad spectrum of energy studies ranging from a quick walk-through of a facility to identify major problem areas to a comprehensive analysis of the implications of alternative energy efficiency measures sufficient to satisfy the financial criteria of sophisticated investors. Three common audit programs are described in more detail below, although the actual tasks performed and level of effort may vary with the consultant providing services under these broad headings. The only way to insure that a proposed audit will meet your specific needs is to spell out those requirements in a detailed scope of work. Taking the time to prepare a formal solicitation will also assure the building owner of receiving competitive and comparable proposals.

Preliminary Audit
The preliminary audit alternatively called a simple audit, screening audit or walk-through audit, is the simplest and quickest type of audit. It involves minimal interviews with site operating personnel, a brief review of facility utility bills and other operating data, and a walk-through of the facility to become familiar with the building operation and identify glaring areas of energy waste or inefficiency. Typically, only major problem areas will be uncovered during this type of audit. Corrective measures are briefly described, and quick estimates of implementation cost, potential operating cost savings, and simple payback periods are provided. This level of detail, while not sufficient for reaching a final decision on implementing a proposed measure, is adequate to prioritize energy efficiency projects and determine the need for a more detailed audit.

General Audit
The general audit alternatively called a mini-audit; site energy audit or complete site energy audit expands on the preliminary audit described above by collecting more detailed information about facility operation and performing a more detailed evaluation of energy conservation measures identified. Utility bills are collected for a 12 to 36 month period to allow the auditor to evaluate the facility's energy/demand rate structures, and energy usage profiles. Additional metering of specific energy-consuming systems is often performed to supplement utility data. In-depth interviews with facility operating personnel are conducted to provide a better understanding of major energy consuming systems as well as insight into variations in daily and annual energy consumption and demand.

This type of audit will be able to identify all energy conservation measures appropriate for the facility given its operating parameters. A detailed financial analysis is performed for each measure based on detailed implementation cost estimates; site-specific operating cost savings, and the customer's investment criteria. Sufficient detail is provided to justify project implementation.

Investment-Grade Audit
In most corporate settings, upgrades to a facility's energy infrastructure must compete with non-energy related investments for capital funding. Both energy and non-energy investments are rated on a single set of financial criteria that generally stress the expected return on investment (ROI). The projected operating savings from the implementation of energy projects must be developed such that they provide a high level of confidence. In fact, investors often demand guaranteed savings. The investment-grader audit alternatively called a comprehensive audit, detailed audit, maxi audit, or technical analysis audit, expands on the general audit described above by providing a dynamic model of energy use characteristics of both the existing facility and all energy conservation measures identified. The building model is calibrated against actual utility data to provide a realistic baseline against which to compute operating savings for proposed measures. Extensive attention is given to understanding not only the operating characteristics of all energy consuming systems, but also situations that cause load profile variations on both an annual and daily basis. Existing utility data is supplemented with sub metering of major energy consuming systems and monitoring of system operating characteristics.

AUDIT METHODOLOGY

To maintain a clear focus on the objective of improving overall energy utilization, DYNASPEDE Expert team (BEE Certified Energy Auditors) typically performs an energy audit in six sequential tasks. This approach is taken to insure adequate dialog between all interested parties at key junctures during the project so that only energy conservation measures (ECMs) that are feasible from an operation and maintenance perspective are evaluated in-depth and incorporated into the final recommendations.

Step 1 - Interview with Key Facility Personnel
During the initial audit, a meeting is scheduled between the auditor and all key operating personnel to kick off the project. The meeting agenda focuses on: audit objectives and scope of work, facility rules and regulations, roles and responsibilities of project team members, and description of scheduled project activities. In addition to thee administrative issues, the discussion during this meeting seeks to establish: operating characteristics of the facility, energy system specifications, operating and maintenance procedures, preliminary areas of investigation, unusual operating constraints, anticipated future plant expansions or changes in product mix, and other concerns related to facility operations.

Step 2 - Facility Tour
After the initial meeting, a tour of the facility is arranged to observe the various operations first hand, focusing on the major energy consuming systems identified during the interview, including the architectural, lighting and power, mechanical, and process energy systems.

Step 3 - Document Review
During the initial visit and subsequent kick-off meeting, available facility documentation are reviewed with facility representatives. This documentation should include all available architectural and engineering plans, facility operation and maintenance procedures and logs, and utility bills for the previous three years. It should be noted that the available plans should represent "as-built" rather than "design" conditions. Otherwise, there may be some minor discrepancies between the systems evaluated as part of the audit and those actually installed at the facility.

Step 4 - Facility Inspection
After a thorough review of the construction and operating documentation, the major energy consuming processes in the facility are further investigated. Where appropriate, field measurements are collected to substantiate operating parameters.

Step 5 - Staff Interviews
Subsequent to the facility inspection, the audit team meets again with the facility staff to review preliminary findings and the recommendations being considered. Given that the objective of the audit is to identify projects that have high value to the customer, management input at this juncture helps establish the priorities that form the foundation of the energy audit. In addition, interviews were scheduled with key representatives designated by the facility as having information relevant to the energy audit. These representatives may include major energy consuming system service and maintenance contractors and utility representatives.

Step 6 - Utility Analysis
The utility analysis is a detailed review of energy bills from the previous 12 to 36 months. This should include all purchased energy, including electricity, natural gas, fuel-oil, liquefied petroleum gas (LPG) and purchased steam, as well as any energy generated on site. If possible, energy data is obtained and reviewed prior to visiting the facility to insure that the site visit focuses on the most critical areas. Billing data reviewed includes energy usage, energy demand and utility rate structure. The utility data is normalized for changes in climate and facility operation and used as a baseline to compute projected energy savings for evaluated ECM's.

Utilities generally offer a comprehensive portfolio of rate tariffs and riders that can be tailored to the energy consumption and demand of the end-user. In addition, with the advent of deregulation, energy can be purchased on contract from a number of third party marketers. Using energy consumption/demand characteristics revealed by a detailed analysis of recent utility bills, the optimum energy supply options is identified. In addition, given the high cost of purchased energy it may be cost-effective to produce some of the facility's energy requirements on-site. Options may include: power generators for emergency power and peak-shaving, solar panels, wind power and cogeneration.

Step 7 - Identify/Evaluate Feasible ECMs
Typically, an energy audit will uncover both major facility modifications requiring detailed economic analysis and minor operation modifications offering simple and/or quick paybacks. A list of major ECMs is developed for each of the major energy consuming systems (i.e., envelope, HVAC, lighting, power, and process). Based upon a final review of all information and data gathered about the facility, and based on the reactions obtained from the facility personnel at the conclusion of the field survey review, a finalized list of ECMs is developed and reviewed with the facility manager.

Step 8 - Economic Analysis
Data collected during the audit is processed and analyzed back in our offices. We build models and simulations with software to reproduce our field observations and develop a baseline against which to measure the energy savings potential of ECMs identified. We then calculate the implementation cost, energy savings and simple payback for each of the ECMs being investigated.

Step 9 - Prepare a Report Summarizing Audit Findings
The results of our findings and recommendations are summarized in a final report. The report includes a description of the facilities and their operation, a discussion of all major energy consuming systems, a description of all recommended ECMs with their specific energy impact, implementation costs, benefits and payback. The report incorporates a summary of all the activities and effort performed throughout the project with specific conclusions and recommendations.

Step 10 - Review Recommendations with Facility Management
A formal presentation of the final recommendations is presented to facility management to supply them with sufficient data on benefits and costs to make a decision on which ECMs to be implemented.