In this study, information on energy usage in the United States (U.S.) aerospace manufacturing sector has been analyzed and then represented as energy intensities (kWh/m2) to establish benchmark data and to compare facilities of varying sizes. First, public sources were identified and the data from these previously published sources were aggregated to determine the energy usage of aerospace manufacturing facilities within the U.S. From this dataset, a sample of 28 buildings were selected and the energy intensity for each building was estimated from the data. Next, as a part of this study the energy data for three additional aerospace manufacturing facilities in the U.S. were collected firsthand. That data was analyzed and the energy intensity (kWh/m2) for each facility was calculated and then compared with the energy intensities of the 28 buildings from the sample. Three different indicators of energy consumption in aerospace manufacturing facilities were used as comparators to assist facility managers with determining potential energy savings and help in the decision-making process. On average, aerospace manufacturing facilities in the United States spent 4 cents for each dollar of sale on energy. The energy intensity (kWh/m2) and the power intensity (W/m2) for each facility were calculated based on the actual facility energy bills. The power intensity for these facilities ranges from 34 to 134 W/m2. The energy intensity ranged from 232 to 949 kWh/m2. We found that the power intensity could be used to estimate energy consumption when the annual operating hours of the facility are considered. and to estimate the energy-related carbon dioxide emissions.
As shown in
Buildings are one of the major contributors to climate change and account for more than one third of global energy consumption and responsible for one fourth of CO2 emissions [
In this research, a focus was placed on the energy consumption within aerospace manufacturing. This is an important area and while there are examples of energy intensity quantification for commercial and government sectors Bawaneh et al. [
According to the National Association of Manufacturers, around 93% of the U.S. manufacturing companies believe that high energy prices have negative financial effects on their businesses. Therefore, it is important to reduce and control energy consumption to be able to minimize its negative impacts on these businesses [
Company | Annual revenue ($Millions) | Market capitalization ($Billions) |
---|---|---|
Boeing | 93392 | 193.96 |
United Technologies | 59837 | 99.94 |
Lockheed Martin | 51048 | 85.5 |
Honeywell International, Inc. | 40534 | 108.26 |
General Dynamics Corporation | 30973 | 56.34 |
Northrop Grumman | 25803 | 53.86 |
Raytheon | 25348 | 56.02 |
BAE Systems | 21248 | 26.66 |
Safran | 19159 | 64.69 |
Bombardier | 16199 | 2.29 |
The United States Census Bureau reported that in 2018, aerospace products, aerospace parts, and defense manufacturers spent more than 1.4 billion dollars on electricity and fuels. The aerospace industries spend a disproportion amount on electricity and fuel when comparisons are made to other industries [
NAICS code | Subsector and industry | Total (Billion kWh) |
---|---|---|
336111 | Automobiles | 99.7 |
336112 | Light trucks | 1111.4 |
3364 | Aerospace parts | 2020.2 |
336411 | Aircraft | 66.7 |
According to the EPA report, which was released in the year 2018, energy-related carbon dioxide emissions account for 84 percent of the total emissions in the United States. The industrial sector consumes nearly 33% of the annual energy usage in the United States [
The main objective of this study is to analyze energy use in aerospace manufacturing facilities using published data from the literature and government reports. In addition to the published data, the energy data for three aerospace manufacturing facilities in the U.S. were collected firsthand and analyzed. The energy intensity is defined in this research, as the power consumed in kWh per square meter (kWh/m2) of the building’s footprint. To understand and analyze the energy consumption in aerospace manufacturing facilities, the following approach was followed:
1. Published information on energy usage for aerospace parts manufacturing facilities has been analyzed and compiled.
2. The energy intensity for each manufacturing building was estimated based on the annual energy consumption, the square footage for each facility, and the operating hours.
3. The energy data on utility bills, operating hours, and building area for three aerospace facilities in the U.S. were collected and analyzed.
4. The energy intensity for each of these three facilities was calculated using the actual annual energy consumption and summarized to allow for comparison of trends.
Presented in this section are individual results for three different aerospace facilities in the United States followed by data from a sample of other facilities.
The facility produces metal formed aerospace parts in the Midwest. The energy data for this facility was collected. The total area of the facility was estimated to be around 4293.047 m2. While this data was collected, the facility was operating at only one 8-h shift per day. As shown in
Month | Total energy(kWh) | Total energy(MJ) |
---|---|---|
January | 144,365 | 519,714 |
February | 136,290 | 490,644 |
March | 102,710 | 369,756 |
April | 105,404 | 379,454 |
May | 144,260 | 519,335 |
June | 141,260 | 508,535 |
July | 131,620 | 473,831 |
August | 130,860 | 471,095 |
September | 106,300 | 382,679 |
October | 121,540 | 437,543 |
November | 63,400 | 228,239 |
December | 122,685 | 441,666 |
Total | 1,450,692 | 5,222,491 |
To analyze and understand the energy characteristics for this aerospace facility, the utility bills, operating hours, and building information were collected from the facility. Then the energy intensity was calculated. The annual energy consumption for this facility, based on the utility bills, was provided in kWh and it is equal to 1,450,692 kWh (5,222,484 MJ). The energy intensity is the total energy (in kWh or MJ) divided by the facility area (in square foot or square meter). We have used a unit of kWh/m2 for energy intensity and found the value for this facility to be 337 kWh/m2.
The facility produces metal formed aerospace parts and it is located in the Midwest area of the United States. The total area of the facility was estimated to be 10,172 m2. The data were collected while the facility was running three 8-h shifts per day. To analyze and understand the energy usage for this facility, the utility bills, and building information were collected from the facility. Then the energy intensity was calculated. The energy consumption for 12 months for this facility, based on the utility bills, was equal to 5356311.38 kWh. The energy intensity was found to be equal to 526 kWh/m2.
The facility which located in the Midwest and produces metal formed aerospace parts. The total area of the facility was 5520 m2. The annual energy consumption for this facility, based on the utility bills, was equal to 3,424,488.88 kWh. The monthly energy consumption for the facility ranges from 878,086 MJ in April to 1,260,979 MJ in December. The energy intensity was estimated to be equal to 620 kWh/m2.
In the 2006, the U.S. Department of Energy initiated the Industrial Assessment Center (IAC). The IAC has centers in different areas of the United States to implement industrial energy assessments. Each center implements energy assessments and investigate potential energy savings and find most effective ways to improve energy efficiency such as energy waste minimization and other improvements. The energy assessments include the SIC number, all energy consumption information, annual production rate, facility information and recommendations for savings after changes. To analyze and understand the energy consumption for these facilities, the building and energy information were collected from these IAC reports. Then the energy intensity was calculated. The annual energy consumption for 28 aerospace facilities was collected and analyzed based on the information published on the IAC website. As an example, the Oklahoma State University Industrial Assessment Center conducted an assessment for an aerospace facility in Kansas in 2021 and a sample of the facility information is shown in
IAC Center | Oklahoma State University |
---|---|
Assessment year | 2021 |
SIC | 3728 |
Principal product | Aircraft parts |
Sales | $1,000,000–$5,000,000 |
Plant area (m2) | 9847.718 |
Production hrs. annual | 2,860 |
Annual energy (kWh) | 1,926,024 (6,933,686 MJ) |
The energy intensity was calculated as follows:
For this example:
The energy intensity was calculated using the same method for the 27 other aerospace facilities shown in
SIC. | Annual sales | Area, mm2 | Products | Operating hours | Annual energy total, kWh | Energy intensity, kWh/m2 | Power intensity, W/m2 |
---|---|---|---|---|---|---|---|
3728 | 9,848 | Other aircraft parts and auxiliary equipment manufacturing | 2,860 | 1,926,024 | 196 | 68.384 | |
3728 | $23,000,000 | 6,880 | Aircraft galleys | 8,760 | 2,554,220 | 371 | 42.378 |
3724 | – | 37,161 | Aircraft engines-service & parts | 8,760 | 14,873,090 | 400 | 45.688 |
3728 | – | 18,581 | Other aircraft parts and auxiliary equipment manufacturing | 8,760 | 1,751,120 | 949 | 10.758 |
3728 | $10,000,000 | 13,378 | Aircraft servicing | 8,736 | 6,345,580 | 474 | 54.295 |
3728 | 33,097 | Aircraft manufacturing | 8,760 | 10,078,080 | 305 | 34.760 | |
3724 | 67,355 | Aircraft engines & parts (rebuild & repair) | 8,760 | 32,202,335 | 478 | 54.577 | |
3359 | $15,000,000 | 6,957 | Aircraft and airport lighting systems | 4,680 | 1,783,260 | 256 | 54.773 |
3463 | $7,000,000 | 13,935 | Aircraft and missile components | 4,160 | 3,226,529 | 232 | 55.657 |
3728 | $15,000,000 | 5,481 | Aerospace and land-based turbines | 5,200 | 1,719,937 | 314 | 60.343 |
3728 | $50,000,000 | 22,297 | Aerospace products | 6,000 | 8,622,000 | 387 | 64.448 |
3599 | $24,000,000 | 7,990 | Aircraft parts | 6,552 | 3,695,740 | 463 | 70.599 |
3452 | $25,000,000 | 7,1541 | Aerospace fasteners | 5,087 | 2,691,274 | 376 | 73.956 |
3724 | $12,000,000 | 5,201 | Aircraft components | 4,400 | 1,947,949 | 375 | 85.126 |
3728 | – | 9,290 | Aircraft parts | 2,535 | 2,057,280 | 221 | 87.354 |
3647 | $15,000,000 | 13,935 | Aircraft lighting systems | 2,210 | 2,730,047 | 196 | 88.645 |
3724 | $10,000,000 | 4,225 | Aircraft engine parts remanufacturing | 4,250 | 1,648,320 | 390 | 91.791 |
3728 | $12,000,000 | 13,935 | Aerospace structural components | 4,732 | 6,054,589 | 434 | 91.816 |
3728 | $38,000,000 | 10,034 | Aircraft landing gear repair and re-manufacture | 5,824 | 5,905,558 | 589 | 101.061 |
3728 | $30,000,000 | 9,290 | Aircraft parts | 7,296 | 7,902,015 | 851 | 116.579 |
3645 | $15,000,000 | 41,806 | Lighting fixtures | 3,000 | 16,235,731 | 388 | 129.451 |
2531 | $33,000,000 | 9,941 | Aircraft seat manufacturing | 3,536 | 4,724,596 | 475 | 134.412 |
SIC | Annual sales | Area, ft2 | Products | Operating hours | Annual energy total, kWh | Energy intensity, kWh/m2 | Power intensity, W/m2 |
3728 | $17,000,000 | 14585 | Aircraft Propellers and Drive Systems | 4,312 | 8,536,116 | 585.2358 | 135.722 |
17744 | |||||||
3585 | $30,000,000 | 6317 | Aircraft Components | 5,148 | 5,252,912 | 831.4985 | 161.518 |
3728 | $78,000,000 | 35303 | Aircraft Flooring, Aircraft Ducting | 4,000 | 23,999,834 | 679.8215 | 169.955 |
3728 | – | 3716 | Aircraft Components | 2,340 | 1,433,762 | 385.8223 | 164.881 |
3728 | – | 32516 | Aerospace Metal Processing and Plating | 6,240 | 3,773,600 | 116.0535 | 18.598 |
To get a better understanding of the energy consumption and to compare the case studies energy consumptions with the literature on aerospace facilities energy consumptions, a Boxplot of the energy and power intensities was created. As shown in
The energy intensity (kWh/m2) indicator reflects the actual annual energy consumption for a manufacturing facility which can be used to compare the energy consumption for different facilities with the same operating hours. Comparing the energy consumption for facilities with different operating hours requires another indicator that consider the operating hours. To get a better understanding of the energy usage, another comparison indicator can be used such as the power intensity (W/m2) that has the operating hours considered in the calculations. The power intensity can be calculated as follows:
As shown in
Another indicator that relates the annual sales to the kWh consumed can be used to compare the cost of energy for each facility with the annual sales. For example, a facility with $23,000,000 annual sales and 9,195,192 kWh annual energy consumption, the $/kWh can be calculated as follows:
This means that for every kWh or energy used, this facility has $2.5 dollars in sales. If the price of 1 kWh is 20 cents, then for each one dollar of sale, this business spent 8 cents for energy. The amount of money spent on energy per dollar of sale were calculated for each facility. As shown in
Three aerospace manufacturing facilities were studied and the energy data for these facilities were collected. The energy intensity (kWh/m2) and the power intensity (W/m2) for each facility were calculated based on the actual facility energy bills. The power intensity for these facilities ranges from 80 kW/mm2 for the case 2 facility to 145 W/mm2 for the case 3 facility. It is concluded that the power intensity is a better estimate for energy consumption than the energy intensity since the annual operating hours are considered.
Two different estimated values were used to compare the energy consumption for aerospace manufacturing facilities, energy intensity and power intensity. The average, range, and standard deviation for the power and energy intensity are shown in
Energy intensity, kWh/m2 | Power intensity, W/m2 | |
---|---|---|
Average | 465465 | 9595 |
Standard deviation | 284284 | 4747 |
Median | 389389 | 8888 |
Range | 11891189 | 151151 |
This paper has provided a more complete review of the energy information for the aerospace manufacturing facilities in the United States. This result further contributes to the life cycle of aerospace manufacturing buildings and products by using the result for energy consumption for facilities per square foot or meter. These results can be used in life cycle studies of aerospace manufacturing facilities and products. In this study, three different indicators of energy consumption in aerospace manufacturing facilities were used as comparators. These comparators have been shown to be valuable in assisting facility managers to determine potential energy savings and to help in the decision-making process.
All co-authors have seen and agree with the contents of the manuscript and there is no financial interest to report. We certify that the submission is original work and is not under review at any other publication.