Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Mechanical Engineering

First Advisor

Kurt D. Bassett


The objective of this study was to examine and summarize the results of ten industrial energy audits performed by the Industrial Energy Optimization Program (IEOP) and the Energy Analysis and Diagnostic Center (EADC) programs at South Dakota State University and present typical energy consumption characteristics of manufacturers in the region. The average present energy consumption profile was estimated and the recommended ECOs were ranked based on frequency of occurrence, simple payback period, energy conserved, cost conserved, and ease of implementation. This study examined which characteristics of ECOs can be most useful to industrial personnel such as maintenance supervisors, plant managers, and utility personnel. The SDSU audits were also compared to audits from 18 other EADCs across the country. These EADCs served 455 manufacturers in 1991. The results of the audits were compared as a whole and by Standard Industrial Classification (SIC) code. The SIC codes pertaining to this study were 20 (food and kindred products), 34 (fabricated products), 36 (electrical equipment and supplies), 38 (measuring, analyzing, and controlling instruments), and 39 (miscellaneous manufacturing industries). The size, simple payback, energy and cost breakdown of both the SDSU and EADC database audits were compared. It is hoped that the results of this study will provide insight to those who are interested in reducing energy costs at industrial facilities by showing what types of ECOs may produce the largest energy cost savings, the shortest payback periods, and which ones are the easiest to implement. The following were concluded regarding the analysis of the 10 SDSU industrial energy audits and the subsequent comparison to the industrial energy audit results from the National EADC database in the same time interval. 1) Insulating of hot surfaces are often overlooked and may be one of the best energy conservation opportunities (0.2 yr simple payback period, saving $10,380/yr). 2) The results from the analysis of the 10 audits performed by SDSU showed that the best overall EC Os consisted of insulating hot surfaces, heat recovery, and high efficiency lighting and motors. 3) The most frequently encountered ECOs dealt with lighting (10), motors (10), the building envelope (7), and heat recovery (5). 4) The best ECOs in terms of energy and energy cost conserved were insulating hot surfaces (1,884 MMBtu/yr and $10,380/yr), installing radiant heating (1,815 MMBtu/yr and $8,696/yr) and heat recovery (1,395 MMBtu/yr and $7,660/yr). 5) The best ECOs in terms of shortest payback were insulating hot surfaces (0.2 yr.), installing occupancy sensors (0.7 yr.), and modifying compressed air systems (0.9 yr.). 6) The best ECOs in terms of ease of implementation were insulating hot surfaces (1 - easiest), adding vinyl stripping to dock doors (2 - easy), and modifying compressed air systems (2 - easy). 7) Another conclusion suggested by this study was that a reduction in life-cycle operating costs for a facility could be achieved by investment in energy-efficient structures. For example, re-insulating or addition of insulation to the building envelope is much more difficult and costly to implement once the facility is in operation. 8) The audits performed by SDSU involved smaller industrial energy consumers (82% smaller) than the average audit performed in the EADC database for the same SIC code (9,744 MMBtu and $82,627 per year versus 54,333 MMBtu and $485,304 per year, respectively). 9) The SDSU audits suggested over twice the percentage of energy savings per plant than the EADC group, 27.5% verses 12.7%, respectively. 10) The SDSU audits had a larger simple payback period than the EADC group (3. 7 vs. 0.6 years, respectively). This can be explained by the vastly larger energy use in the EADC plants, leading to more "cherry picking" opportunities, and the greater overall cost of energy for the EADC plants, therefore giving a greater savings for each Btu conserved.

Library of Congress Subject Headings

Energy auditing
Great Plains -- Industry -- Energy consumption
United States -- Industry -- Energy consumption




South Dakota State University



Rights Statement

In Copyright