Industrial Assessment Center
Semester Project
Assessment Date: 12/2/2012
Issue Date: 12/12/2012
PROJECT ENGINEERS
/ / / / / Jesse MonnYour Names and Pictures Here / Tim Raffio / Jesse Monn / Mithun Nagabhairava / Dustin Pohlman
Energy Engineer / Energy Engineer / Energy Engineer / Energy Engineer / Energy Engineer
PREFACE
http://academic.udayton.edu/kissock/http/EEM/EEMmain.htm
The objective of this report is to identify and evaluate opportunities for energy efficiency. The evaluation process is based on the data gathered during a one-day site visit and is thereby affected in detail and completeness by limitations on time at the site and access to processes. In cases where assessment recommendations (ARs) involving engineering design and capital investment are attractive to the company, it is recommended that the services of a consulting engineering firm be engaged (when in house expertise is not available) to do detailed engineering design and to estimate implementation costs. The contents of this report are offered as guidance. The University of Dayton, and all technical sources referenced in the report do not: (a) make any warranty or representation, expressed or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report /
TABLE OF CONTENTS
I. Executive Summary 6
Summary of Assessment Recommendations 9
Summary of Selected Exemplary Practices 13
II. Baseline 14
Corporate Data 15
Utility Analysis 15
Current Electric Rate Structure – Plant 16
Current Electric Rate Structure – Offices 17
Electricity Use – Plant 18
Electricity Use – Offices 19
Electricity Use - Total 20
Electricity Cost Breakdown 21
Purchasing Pollution-less Renewable Electricity 22
Natural Gas Use 23
Marginal Costs 24
Lean Energy Analysis 25
Lean Energy Analysis of Electricity Use 26
Lean Energy Analysis of Natural Gas Use 31
Plant Energy Balance 37
Electricity Use by Equipment 37
Natural Gas Use by Equipment 39
Plant Layout 39
III. Assessment Recommendations (ARs) 41
Energy Efficient Lighting 42
Energy Efficient Motor Systems 44
AR 1: Turn Off Hydraulic Motors When Not In Use 45
Energy Efficient Compressed Air Systems 49
Current Compressed Air System 52
AR 2: Lower Operating Pressure of Air Compressor from 125 psig to 110 psig 55
AR 3: Install a Refrigerated Dryer and Eliminated Timed Condensate Purge 58
AR 4: Install Necessary Ductwork to Supply Outdoor Air to Air Compressors 62
Energy Efficient Heating, Ventilation and Air Conditioning 65
AR 5: Keep Loading Dock Doors Closed Until Ready to Load 67
Comment 1: Replace Old Roof with a White Roof 70
IV. Measurement and Benchmarking 71
V. Financing and Implementation Options 72
VI. Appendix 74
CO2 Emission Factors 74
Energy Inflation Rate 74
Report UD0845 University of Dayton Industrial Assessment Center v
I. Executive Summary
Our team visited your facility on December 2, 2011. We analyzed your plant’s energy use and production processes. Currently, total utility costs are about $98,769 per year and total energy related CO2 emissions are about 684 tonnes per year. With the help of plant personnel, we identified 5 savings opportunities with a total potential energy savings of about $6,883 per year and 53 tonnes of CO2 emissions per year. The total potential savings of all energy savings recommendations would decrease current plant utility costs by about 7% and CO2 emissions by about 8% per year. /* Potential savings if all recommendations were implemented
The following graph shows estimated savings by energy system. The largest cost savings opportunities were in the Compressed Air, Motors, and HVAC systems.
The following graph shows the initial investment and annual cash flows for 10 years if every AR were implemented. The combined internal rate of return is 104% without energy inflation and 107% if energy costs continue to escalate at 3% per year.
Many of these recommendations originated from discussions with you or plant personnel. It was a pleasure to work together to identify these opportunities.
Summary of Assessment Recommendations
Utility Recommendations
AR 1: Turn Off Hydraulic Motors When Not in Use
The plant has two Accushear shearing presses and three spiral machines with hydraulic motors. These motors are left on during times when the lines they serve are not in use, such as employee breaks or periods between production operations. These hydraulic motors do not have controls to shut them off automatically and are left on when not in use, for as much as 2 hours per day. Motors that are left idle continue to draw power and contribute to electricity costs. During our visit, we logged the current draw of the hydraulic motor from one of the shearing presses and the 300 spiral machine. The following graphs show the current draw from each of these motors during a two hour time interval, measured once every second. The flat sections represent times when the motor is turned on, but is not in use. The very tall current spikes in the data represent motor startup. We recommend installing the necessary programmable logic controllers to turn off all hydraulic motors when not in use for longer than 5 minutes. This would save about $1,244 per year with a 5 month simple payback and a 269% rate of return. /AR 2: Lower Operating Pressure of Air Compressor from 125 psig to 110 psig
The plant is served by a 50-hp air cooled Ingersoll Rand air compressor with one 25-hp and one 20hp compressor as backups. The air pressure is set to 125 psig, but the highest pressure used in the process is 100 psig. There will be some pressure losses in the distribution system and through the air dryers, but if the air pressure can be lowered down to 110 psig, the air compressor would not have to work as hard which would result in electricity savings. We recommend lowering the compressed air pressure from 125 psig to 110 psig, or as low as possible. This would save about $534 per year with an immediate simple payback and thus and infinite internal rate of return. /II. Baseline
Your baseline analysis here.
Eliminating Plant CO2 Emissions at Zero Additional Cost
Anthropomorphic CO2 emissions from the combustion of fossil fuels have increased the concentration of atmospheric CO2 from 280 to 350 ppm and raised the earth’s temperature by .7 C since the industrial revolution. Stabilizing atmospheric CO2 at levels that avoid the worst effects of global warming require significant reductions in emissions from all sectors of society. Your plant can lead the way by completely eliminating net carbon emissions at no additional cost by investing savings generated from energy efficiency in renewable energy.
To see how, consider the following. Our assessment may identify energy efficiency opportunities that reduce plant energy use by 17% with a 2-year simple payback. In your plant, the energy efficiency savings and implementation cost would be:
Using a 5% discount rate and 10-year life of savings, the annualized energy efficiency savings would be:
CO2 emissions after the energy efficiency measures have been adopted would be:
Renewable Energy Certificates (RECs) effectively enable electricity users to purchase electricity from wind turbines, which generate electricity with zero CO2 emissions. RECs typically cost about 1.5 cents per kWh. Certified providers of RECs can be found at www.green-e.org. CO2 emissions from regional coal dominated utilities are about 2 lb-CO2/kWh. Thus, the CO2 emissions avoided by purchasing renewable energy using the savings from energy efficiency would be:
Thus, the net CO2 emissions and cost to the plant would be:
Marginal Costs
Your marginal costs here.
Marginal costs represent the cost savings you would see from modifying your usage by a given amount. Marginal costs are calculated based on the electricity, natural gas and water and sewer utility bills that you provided. We use the following marginal costs to calculate savings in all of our recommendations.
Electrical Energy Plant: $0.0622 /kWh
Electrical Energy Offices: $0.0627 /kWh
Electrical Demand: $6.55 /kW-mo
Natural Gas: $8.96 /mmBtu
Lean Energy Analysis
Your lean energy analysis here.
Plant Energy Balance
Plant Layout
III. Assessment Recommendations (ARs)
The primary goal of our assessment is to help you reduce your waste, energy and production costs. The Assessment Recommendations (ARs) that follow include descriptions of specific conservation measures and our estimates of the savings and cost of each recommendation. These recommendations do not constitute detailed engineering plans or designs. Additional engineering services may be necessary to implement certain recommendations.
AR 1: Turn Off Hydraulic Motors When Not In Use
ARC: 2.6218.1 / Annual Savings / Project Cost / SimplePayback / Internal Rate of Return
Resource / CO2 (tonnes) / Dollars / Capital / Other / Total
Electrical Energy / 20,000 kWh / 14 / $1,244 / - / - / - / - / -
Total / - / - / $1,244 / $500 / - / $500 / 5 months / 269%
Analysis
The plant has two Accushear shearing presses and three spiral machines with hydraulic motors. These motors are left on during times when the lines they serve are not in use, such as employee breaks or periods between production operations. These hydraulic motors do not have controls to shut them off automatically and are left on when not in use, for as much as 2 hours per day. Motors that are left idle continue to draw power and contribute to electricity costs.During our visit, we logged the current draw of the hydraulic motor from one of the shearing presses and the 300 spiral machine. The following graphs show the current draw from each of these motors during a two hour time interval, measured once every second. The flat sections represent times when the motor is turned on, but is not in use. The very tall current spikes in the data represent motor startup. /
Accushear Shearing Press
Current Draw from Shearing Press
Current Draw from Spiral Machine
Recommendation
We recommend installing the necessary programmable logic controllers to turn off all hydraulic motors when not in use for longer than 5 minutes.
Estimated Savings
The power draw of a three-phase motor can be calculated using the following equation:
Power kW = Current A × Voltage V × 3 ×Power Factor kWkVA × 1 kW1,000 W
The typical power factor for small electric motors is about 80%. We measured the current draw of the 30-hp hydraulic motor on the shearing press to be 18.8 A when idle. Therefore, the power draw of the motor when left on but not is use is about:
18.8 A ×480 V × 3 ×0.80 × 1 kW1,000 W= 14.0 kW
According to management, the usage of the hydraulic motor we measured represents the activity of the other shearing press. However, the second shearing press is powered by a 20-hp motor. Therefore, we estimate the power draw of the second shearing press during idle times is about:
14.0 kW × 20 hp30 hp =9.3 kW
We measured the current draw of the 30-hp hydraulic motor on the 300 Spiral Machine to be 22.5 A when idle. Therefore, the power draw of the motor when left on but not in use is about:
22.5 A ×480 V × 3 ×0.80 × 1 kW1,000 W= 16.7 kW
According to management, the usage of the hydraulic motor we measured represents the activity of the other spiral machines. There are typically two spiral machines in use per day.
The data show that the hydraulic motors on the shearing press and spiral machine are left on when not in use for about 30 minutes and 15 minutes, respectively, during the two hour time interval that data was collected. According to management, the two hour time interval represents normal use throughout the eight hour day. Therefore, the annual energy savings for turning off each of the hydraulic motors when not in use are shown below.
Shearing Presses
14.0 kW+9.3 kW × 2 hoursday × 5 daysweek × 50 weeksyear = 11,650 kWhyear
Spiral Machines
2 machines × 16.7 kW × 1 hourday × 5 daysweek × 50 weeksyear = 8,350 kWhyear
Therefore, the total annual energy savings would be about:
11,650 kWhyear+8,350 kWhyear= 20,000 kWhyear
The annual CO2 emissions reduction would be about:
20,000 kWhyear × 1.56 lb-CO2kWh × 1 tonne2,205 lb-CO2= 14 tonnes-CO2year
The annual energy cost savings would be about:
20,000 kWhyear × $0.0622kWh =$1,244 /year
Estimated Implementation Cost
According to management, programming controls would cost about $100 per motor. Thus, the implementation cost would be about:
5 motors × $100motor=$500
Estimated Simple Payback and Internal Rate of Return
The simple payback for this recommendation would be about:
$500$1,244 /year × 12 monthsyear=5 months
Assuming the project lasts for 10 years and an energy inflation rate of 3%, the internal rate of return is 259%. The life cycle of this project can be seen in the following graph.
VI. Appendix
CO2 Emission Factors
1.56 lb. CO2/kWh is the RFCW regional average from "EPA Climate Leaders Simplified GHG Emissions Calculator (SGEC), Version 2.8", http://www.epa.gov/climateleaders/
117 lb. CO2/mmBtu natural gas is from “Benchmarking Air Emissions Largest Electrical Producers in the U.S.”, National Resources Defense Council, www.nrdc.org, 2006.
200 lb. CO2/mmBtu coal is from “National Air Pollution Emission Trends Report: 1900 – 1998”, U.S. E.P.A., EPA-454/R-00-002, March, 2000
270 lb. CO2/1000 lb steam uses 200 lb. CO2/mmBtu from above and calculation of coal required to generate Appleton’s mix of 135 psig and 50 psig steam.