Contract Management Using Industrial Energy Management & Reporting Systems
James E. Robinson, P.E., P.Eng., CEM, CEP Principal Project Engineer DES Global, LLC Greenville, SCABSTRACT
Energy Management and Reporting Systems (EMRS) are rule-based control systems with a record of reduc-ing energy usage and CO2e emissions while
optimiz-ing electrical generation in a real time environment. The rule set successfully optimizes energy contracts in complex business relationships. This paper ex-plores the integration of the EMRS qualification process and implementation of EMRS in large corpo-rate structures with examples of contract management for some surprising results.
OBJECTIVE
The objective of this paper is to present the conver-gence of the technical and business benefits of the EMRS applications in a large corporate environment. While the technology is well documented (1)(2), the realization of the business benefits in contract man-agement, regulatory compliance, and policing corpo-rate policy is a relatively new finding. The paper structure is:
A general discussion the EMRS technolo-gies.
A review of the Level 1 and Level 2 Power-house Assessment methodology used to quantify the opportunities available through the application of EMRS systems.
A discussion of a typical project implemen-tation.
Present the reporting mechanism that assures sustainable results and compliance with cor-porate business objectives.
BACKGROUND
Both manufacturing processes and power plants are improving through the continuous evolution of processes and process control system technologies. But each new technology forces a reevaluation of assessment, implementation, and maintenance metho-dologies to assure proper implementation of these new technologies. The EMRS implementation is an example of this evaluation process. Figure 1 - EMRS Powerhouse Assessment and Implementation shows a current configuration with the EMRS teams inte-grated into a large corporate organization. The EMRS Assessment and Implementation Teams report
to the corporate office to streamline system deploy-ments and increase the system effectiveness to the corporate departments responsible for powerhouse management and operation. This paper will explore the convergence of the technology implementation with the business objectives to provide standardiza-tion across multiple manufacturing facilities.
EMRS Corporate Driven Deployment
A corporate driven deployment assures a uniform approach that accelerates fleet implementation while improving the depth, accuracy, and returns from the powerhouse assessments and project implementation. Coordination between the corporate office and facili-ties assure proper scheduling, elimination of duplicate effort, and uniform project implementation resulting in a higher degree of success. As project deploy-ments progressed, the benefits for contract reporting and management was identified and integrated into the EMRS assessment and implementation support mission. The results have been positive.EMRS Implementation Team
Facilities
Facility Utility Optimizer Capital Projects Operations Energy Services Environmental Services Energy Contracts EMRS Assessment Team Facility Utility Optimizer Facility Utility Optimizer Facility Manager(s)Corporate
VP Energy InitiativesEMRS Assessment & Implementation Teams
Turbine Specialist Combustion Specialist CO2 Specialist Engineering & Construction
Corporate Driven EMRS Deployment
Figure 1 - EMRS Powerhouse Assessment and Implementation
EMRS TECHNOLOGIES
The EMRS is a combination of technologies proven to provide a low cost, high return, control system and engineering services project to reduce emissions(5) and operating cost while improving reliability and safety. At the regulatory level, this technology im-proves the agility and reliability of the powerhouse to properly respond to the business unit utility needs. At the advanced control level, operating, engineering, energy contracts, and corporate policy is integrated into a consistent rule set to optimize powerhouse per-formance. In general, a prioritized rule set would provide the following behavior:
Maintain equipment safety Satisfy environmental limits Keep the powerhouse on line Keep the processes units on line Save money
The result is an operating system that provides a con-sistent standard of behavior to reduce the cost of pro-duction while providing higher quality and safety across the corporate fleet. As the EMRS pushes to an optimal solution, a constraint reporting system pro-vides historized process metrics that identify how to improve performance and assure sustainable results. The following section discusses the project assess-ment and impleassess-mentation methodology.
PROJECT
ASSESSMENT
AND
IMPLEMENTATION
The process begins with a powerhouse assessment to identify the type and size of the opportunities. The assessment is designed to interface with the corporate project approval structure and provide the appropriate details for the project approval documentation. A typical corporate structure breaks the approval process into several logical components based on the project requirements. For the purpose of this discussion the powerhouse assessment will be identified as a Level#1, Level#2, and Level#3. Level#1 – Qualifies if a project is available. The objective is to inform the client of the opportunities, estimate the possible returns, and provide an estimated cost per corporate project approval guidelines of usually +/-50%.
Level#2 – Quantifies the benefits from the project selected. This continues to be a speculative undertaking as a well thought out solution is developed. In the process of developing the solution,
a forecast of project returns is developed and constraints to project success are identified. The result is a reduction of project uncertainty for the client with the development of a +/-25% cost estimate per corporate guidelines.
Level#3 – Reduces Risk when project execution requires extensive facility modifications. An example would be the implementation of a DCS or process capital modification. This often requires a Front End Loaded (FEL) study and is designed to a +/-10% construction grade estimate.
Experience has shown that most facilities qualify for an EMRS project. To accelerate project selection and execution, the Level#1 and Level#2 assessments are often combined in the initial powerhouse assessment to minimize travel and living cost and the distractions to the facility operations team.
Powerhouse Assessment
A powerhouse assessment is the primary source of information for making management decisions. To be effective the assessment must be well organized, comprehensive, and properly verified. Figure 2 -Assessment Structure presents the structure of the Powerhouse Assessment. The first step is to define the client objectives by capturing the current state of the process and control system. Performed diligently, the knowledge gained from the assessment will trans-late into a lower cost of goods sold and progress to an even higher level of process safety and reliability. Often, findings from the assessment will provide “in-finite return projects” around standard operating pro-cedures, energy contracts, or process issues that re-turn significant savings at minimal or no costs before the project begins.
System Operation Philosophy
To deal with the varying steam demands typical in industrial applications, boilers must be designed and controlled as a system to provide top efficiency at all steam demands. This requires the boilers to act transparently as one continuous steam generator as much as possible, reducing the effect of discontinuities and transitions attributable to changing loads, variable fuel quality, and fuel mix. The various constraints on the operation of individual equipment must be respected in order to provide a robust and reliable powerhouse. The properly automated steam system should be agile enough to meet changing demands and fuel handling difficulties without excessive loss of steam to venting or propagating upsets to downstream consumers.
Level#1 Assessment
Figure 3 - Level #1 Powerhouse Assessment provides an example of a typical powerhouse Level#1 assessment point of view. The objective of the Level#1 assessment is to qualify the operating effectiveness of the combustion, electric generation, and steam distribution system envelop without the extensive study of the individual process components reserved for the Level#2 Assessment. The Level#1 study looks at the operating envelopes and can be developed from historical data supplied by the facility. The operating effectiveness in powerhouse operations can be boiled down into just a few performance measures around the operating envelop of the boilers, turbines, and steam distribution system. 1. Fossil Fuel Effectiveness (FFE) – boiler and fuel
allocation
2. Power Generation Effectiveness (PGE) – turbine, PRV, and atmospheric vents
3. Steam Delivery Effectiveness (SDE) – steam distribution and electric generation
When evaluating a powerhouse the performance indicators are based on the entire steam load for an extended period. Calculated this way, the effectiveness indicators encompass not only the traditional equipment efficiency measures, but also the effectiveness of how the steam system is run. Experience has shown that most steam systems are capable of vastly improved efficiency and reliability without major design changes. Analysis of operational history indicates that sustained operation at elevated performance levels has been previously achieved through operator skill and/or coincidence. This proves that the physical systems are capable of
improved operation. Implementing systems and procedures that reduce variability, drive performance towards economical operation, and apply the process manager’s judgment at all times can raise average performance dramatically. Only then does it make sense to investigate improving the inherent efficiency of the boilers and turbines through capital intensive projects.
This approach essentially becomes an effort to remove all the barriers to previously best-achieved operation. Design of control systems and procedures that continuously strive for reduced variability and economic operation, and remove indiscriminate operating technique become the primary tools of this approach. Reduced variability facilitates future improvement efforts because much more can be understood about the process, its constraints, and opportunities for improvement. Side benefits typically include improved tolerance for upset conditions, increased awareness of management objectives, and less, but more effective, troubleshooting efforts. Management oversight requirements are greatly reduced.
Figure 3 - Level #1 Powerhouse Assessment
Power Generation Effectiveness (PGE) Fossil Fuel Effectiveness (FFE)
Fossil Fuel Effectiveness (FFE)
The measure of overall Fossil Fuel Effectiveness FFE is (Units of Fossil Fuel)/ (Units of Steam Produced) presented in units common for the powerhouse reporting system and addressing two types of efficiency:
1.
Combustion Efficiency
Combustion efficiency is a measure of an individual boiler’s ability to convert fuel to steam. The measure of combustion efficiency is (Btu Steam Generated) / (Btu Fuel Consumed). Combustion efficiency is a function of boiler design and chosen operating conditions. Each boiler that participates with other boilers to supply a given steam demand has a different combustion efficiency and contributes to overall steam generation combustion effectiveness differently. The mix of boilers used to produce mill steam demand should be optimized for every steam load.
Improvement in combustion efficiency for any particular boiler results in less overall fuel demand. With controls designed to continuously maximize cheaper fuels, any increase in combustion efficiency reduces the demand for the most expensive fuels.
2.
Fuel Cost Efficiency
Fuel cost efficiency measures overall cost effectiveness of powerhouse operation. Cost efficient operations attempt to minimize cost of steam by using the cheapest fuel in the most efficient boiler at any given load point.
Fuel cost efficiency is a function of the ability to differentiate fuels in individual boilers and among individual boilers. The ability to burn cheaper fuels is commonly limited by fuel delivery constraints and the lack of suitable combustion controls to deal with the higher BTU variability common with cheaper fuels. Opportunities in fuel cost efficiency also lie in improved turndown of more expensive fuels, as well as a more rational approach to insurance or “just in case” operations.
Data Handling
Data points for this analysis are hourly averages for an entire year. From this data we eliminated bad data points, where equipment was out of service or subject to operational problems for the calculation basis. Hourly averages are used because they indicate the
system was operated at approximately this level for an hour. This demonstrates that this mode of opera-tion was physically possible and sustainable.
Level#1 Estimating Tools
Table 1 - Level#1 Tool Set resents the Cost Basis and Control Strategy that is normally applied in a Level#1 Analysis. The calculation methodology is well do-cumented and detailed papers are available through the IETC on line archives(3). The three primary metrics and control strategies presented in this table are the FFE, PGE, and SDE.
Figure 4 - FFE Development and Control Strategy presents the Cost Metrics to calculate the fuel savings opportunity and the Control Strategy applied to move the more expensive operating points towards the lower operating cost. In this instance 75% was chosen as the target metric because experience shows this is often obtained.
Figure 5 - PGE Development and Control Strategy presents similar Cost Metrics to calculate the savings opportunity and the Control Strategy associated with electric generation. A word of caution, under certain circumstances overall system economics and powerhouse stability must be evaluated. Sometimes the right decision is to bypass the turbine when electric prices are low relative to steam generating cost. Under those circumstances steam BTU's should be applied directly to the process and not used for generation.
Figure 6 - SDE Development presents the Cost Metrics for evaluating the steam distribution system. A concern is that the PRV's and vents may not have flow measurements. This requires an alternate strategy to estimate flow rates. Typically, linear flow proportional to valve opening with a 5% allowance of no flow to allow for valve movement off the valve seat seems to be reasonable.
Analyses of special units are sometimes required. Recovery boilers, fluidized bed boilers, and a vast array of other powerhouse equipment may require quick evaluations to frame Level#1 opportunities. These evaluations can be run from TAPPI and ASME efficiency short forms.
Table 1 - Level#1 Tool Set Fossil Fuel Effectiveness (FFE)
Process Metric: MMBTUfossil fuel/KPPHsteam
Cost Reduction Strategy: Decrease the fossil fuel metric use by driving the poor performers down into the preferred lower cost operating region.
Control Strategy: Improved combustion and boiler load allocation to use the lowest cost fuel in the highest efficiency units.
Typical Target: 75%tile operating average FFOffset$: Expensive Fuel$ - Inexpensive Fuel$
Figure 4 - FFE Development and Control Strategy
Y-Axis presents the FFE coefficient in terms of MMBTUfossil fuel/KPPH steam.
X-Axis defines steam production rate in bins of 50 KPPH
Power Generation Effectiveness (PGE)
Process Metric: MWHrsteam generation/KPPHtotal steam
Cost Reduction Strategy: Increase generation by moving the poor performer up into the preferred operating region.
Control Strategy: Increase steam through the turbines by closing the PRV's bypassing the turbines, improving turbine load allocation, header spreading to increase the MWHr/KPPH.
Typical Target: 75%tile operating average PGOffset$: Utility Cost$ - Generation Cost$
Figure 5 - PGE Development and Control Strategy
Y-Axis presents the PGE coefficient in terms of MWHrelectrical/KPPHsteam
X-Axis defines steam production rate in bins of 50 KPPH of steam production.
Steam Distribution Effectiveness
Process Metric: KPPH steam loss reduction. Cost Reduction Strategy: Totalize the steam bypassing the turbines and lost to atmospheric venting. Reduce when economically correct. Control Strategy: Turbine extraction flow limiters, PRV and set point monitoring and control, Zed model predictive header pressure control.
Typical Target: 80% to 90% of lost steam.
SDOffset$: Venting: BTU value of steam lost to process.
SDOffset$: PRV: Electric generation value minus the make up cost of BTU to process.
Note: many PRV's do not have flow meters, agree on flow/valve output characterization and valve seat lift off before estimating flows.
Figure 6 - SDE Development
Y-Axis presents the estimated steam flow in terms of KPPHsteam
X-Axis is valve position from facility historian.
7 5 % 2 5 % P o in t P o p u la ti o n P G E = M W H R (G e n e ra ti o n ) K P P H (S te a m ) 7 5 % 2 5 % P o in t P o p u la ti o n F F E = M M B T U (F o s s il F u e l) K P P H (S te a m ) 2 5 % O P 5 0 % O P 7 5 % O P 1 0 0 % O P 1 0 5 % O P -5 % O P V a lv e F lo w L if t O ff
Project Scoping Tool
The results of the Level#1 estimates can generate effective project scoping information. Figure 7 - Im-provement Opportunity presents the Level#1 FFE analysis and results from a typical project(3). The Performance Improvement Opportunity is a sensitivi-ty curve that steps the FFE through a range of 0% through 100% in 10% increments. Experience shows that EMRS project execution provides a 75%tile solu-tion but, the project provides a “Sticky Factor” of improved performance which cannot be measured before the project begins. These improvements can be operator behavior, minor modifications, and con-current implementation of additional energy projects providing additional savings. As shown in Figure 7, the project estimate was $990K/year with an expected result of $1.1M/Year. The final result was $1.7M/year using $6/KSCF gas and 8,400 hour year.
Figure 7 - Improvement Opportunity
LEVEL #2 ASSESSMENT
The next phase of the audit process includes a Level #2 powerhouse assessment. At this point, the project is still speculative while the project details are devel-oped, constraints identified, and savings opportunity quantified. Once completed, the capital approval process could authorize capital expenditures for projects or a Level#3 requested for a more detailed design. At this point, the project approval process may require the involvement of several business de-partments outside the capital project group. Exam-ples would be operations, contracts, environmental, and energy procurement.
The following Level#2 calculations are required to support the organization decision process:
1. Fuel Contract Analysis to establish the study basis for the steam cost calculations.
2. Electrical Utility Contract Analysis to develop the study basis for the electric generation pur-chase or sale of electricity.
3. Co-Generation contracts that affect the operation of the powerhouse costing.
4. ASME PTC6S performance calculations around the condensing and backpressure turbines. 5. ASME PTC4S performance calculations around
the combination and power boilers.
6. Steam distribution model of steaming rates, tur-bine generation, PRV operation, and atmospheric venting to identify savings opportunities (4). 7. CO2e reduction estimate using the Tier#1
Calcu-lation Basis under the GHG reduction guide-lines(5).
8. Additional evaluations to support specialized equipment such as Chemical Recovery Units.
Figure 8 - Level 2 Powerhouse Assessment TARGET PROFILE - PB#4 and PB#5 REMOVED
Previous Advanced Control System - 1/1 to 12/31/2004 - 7,382 Hours 2004 Power Boiler PB#1, PB#2, and PB#3 - Ex PB#4, and PB#5
Performance Improvement Opportunity
$-$1,000,000 $2,000,000 $3,000,000 $4,000,000 $5,000,000 $6,000,000 $7,000,000 $8,000,000 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Improvement (%) A n n u a l S a v in g s ($ ) PB1, PB2, PB3 - 7238 Hours Data PB1, PB2, PB3 - 8400 Hour Forecast Project Guarantee using
7238 Hour Data Set at $7/KSCF US$990K/Year
Guarantee Safety Factor using 8400 Hour Year at $7/KSCF US$1,115K/Year Results as of 2/13/2006 using 8400 Hour Year at $6/KSCF US$1,759K/Year (with PB#4&5)
Power Generation Effectiveness (PGE) Fossil Fuel Effectiveness (FFE)
Low Pressure Header High Pressure Header
Intermediate Pressure Header
L P G1 M P H P P R V Biomass Coal TDR #2 Oil CB1 DS DS P R V DS V e n t G2 M P H P DS DS FBB2
Steam Distribution Effectiveness (SDE)
Biomass Coal Coke Natural Gas Co-Gen Contract Electrical Utility Contract Fuel Contract CO2e Estimate
The data collection and analysis phase of the Level #2 Assessment, can become complex and detailed below.
1.
Facility Walk Down
The facility walk down often uncovers "infinite return" projects where savings opportunities are obtained with little or no cost. Specific areas are fuel and air control and measurement, tie line and power factor measurement issues, fuel supply is-sues combined with coordination between oper-ating units, camera locations and bed manage-ment, sensor probe locations, and instrumenta-tion calibrainstrumenta-tion issues to name a few.
2.
Electric and Fuel Contracts
The fuel and electric measurement systems are validated against billings. Any abnormalities with the internal energy measurement system and the external utility system are discovered because they must balance for the EMRS fuel costing sys-tems and provide reliable and repeatable mea-surements for control. This entire process is beneficial for the energy procurement team.
3.
Co-Generation Contract Analysis
Co-Generation contracts seem to always have opportunities. First, these contracts are often mi-sunderstood due to the contract size and different responsibilities of the purchasing and operating groups. This confusion can provide opportuni-ties and the review process brings a common un-derstanding to all the teams. Often the savings opportunities come from automation of Co-Generation invoices and billing verifications, on-line advisors to assist operators maximize the Co-Generation contracts, and closed loop control designed around the contract terms maximizes the benefits to the client.4.
Equipment Efficiency Calculations
The PTC4 and PTC6 efficiency calculations around the major equipment will identify system mismanagement caused by bad measurements af-fecting efficiency calculations, incorrect efficien-cy calculations, or bad breakpoint decisions. A simple error can result in significant losses on a large industrial energy bill.5.
Process Modeling
A combined model of the steam system, electric system, and energy contracts often identifies
op-portunities. The ability to run different operating scenarios around the energy contracts versus overall system performance provides significant opportunities, especially around real time con-tracts. A second advantage is the ability to pro-vide a graphical representation of the process op-erating changes that results in the targeted sav-ings. Figure 9 - RTP Tie Line Example shows that revised tie line profile to obtain over $500K/year is savings. A closer examination of the Figure 9 shows these savings come from pur-chasing less expensive utility electricity.
Figure 9 - RTP Tie Line Example
Level#1 and Level#2 Assessment
With the completion of Level#2 Assessment, the project prerequisites are identified, the risk clarified, and the savings quantified. Often this is enough to authorize a project because the benefits of an EMRS project are often obtained with minimum expense. Often the prerequisites consist of correcting deferred maintenance issues and adding sensors that can be done by the mill.
An interesting finding is that our existing clients re-quest concurrent Level#1 and Level#2 Assessments. The vast majority of the facilities can justify an EMRS project and breaking the analysis into two different trips lengthens the implementation schedule and minimizes corporate and facility operations dis-tractions.
LEVEL#3 ASSESSMENT
The Level#3 Assessment is required when significant work is required to prepare the facility for the EMRS.
0 100 200 300 400 500 600 700 800 -2 0 -18 -16 -14 -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 14 16 18 20 H o u rs MWHr (+) Import/(-)Export Tie Line Revised 01Oct2009 to 30Sep2010
Once the magnitude of the project is identified, the capital projects team will execute a front end loaded engineering study.
Another finding is that capital projects required under the Level#3 initiatives take time. Level#2 Assess-ment updates will be requested during the Level#3 upgrades to measure performance improvements of the capital projects.
IMPLEMENTATION
Figure 10 - Completed System Architecture presents a recently completed project. The facility has a com-plex electrical contract that can result in penalties should a peak be set during high grid demand with the electrical suppliers. The date and time of that peak is discovered at the end of the month. To mitigate this billing risk, a third party advisory system was inte-grated into the EMRS taking weather and a statistical model of the grid to identify the risk of setting a con-current peak. The mill developed an arbitrage system to balance billing risk against end of month surprises. Delivered natural gas prices are obtained from the internet supplier and the cost of solid fuel are ob-tained from the facility historian with real time opti-mization done in the Energy Command Portal (ECP)
in closed loop to drive the powerhouse accordingly.
First, Header Pressure Control
To pursue the savings opportunities, the agility of the powerhouse was improved. To accomplish that, the High Pressure Header is now controlled by a ZED predictive pressure controller that integrate seamless-ly with the EMRS control system and DCS regulatory control system. The advantage of this architecture is the ability to place components into a supervisory PC or the DCS control system as required for process dynamics, system constraints, and best fit.
1. The controller is aware of the steam supply gain and time constant capability of fuels, boilers, tur-bines, and PRV’s from measured performance data.
2. The controller is also aware of the Mill Load demands from valve output positions combined with flow and pressure measurements and can execute steam header control strategies.
This combination allows the controller to anticipate the required moves and maintain the critical process steam header requirements that cannot be obtained using the conventional PID regulatory control.
Figure 10 - Completed System Architecture
V e n t V e n t M IL L L O A D S
Second, Overall Combustion
Optimiza-tion and Control
There were several optimization opportunities found in the combustion system.
1. Recovery Boilers had an advanced control strat-egy installed that increased the steam produc-tion/black liquor ratio and improved reduction efficiency reduces liquor cycle dead load and energy usage across the entire mill.
2. Combination Boiler turn down was improved by fixing instrument problems.
Third, Overall System Optimization and
Control
The EMRS control system is shown at the top of the control system as a supervisory overlay on the exist-ing DCS for the coordination and optimization of the boilers and PRV’s.
1. Performance data is historized in the PI server with the constraint reporting and lost opportunity
information. This is available to the corporate energy dashboard and exception reports with dai-ly reminders through the email reporting system. 2. Local maintenance and tuning can be conducted
by the mill personnel. Remote access is permit-ted with overall system diagnostic and mainten-ance supports via a secure internet connection.
Forth, Constraint Reporting and Lost
Opportunity Reporting System
The EMRS has a unique ability to identify and quan-tify process and control system constraints that pre-vent the system from performing better. As presented in
Figure 11 - Constraint and Lost Opportunity Reports, the EMRS uses real time operating data and if the control system encounters a constraint, the Constraint Reporting Mechanism identifies the constraint and will historize both magnitude and frequency of that constraint. The lost opportunity calculator will eva-luate the current operation against proven best per-formance to totalize lost opportunities.
CONCLUSION
This paper has presented the EMRS concept, methods used to quantify the opportunities, the techniques used to obtain the benefits, the reporting system to maintain the benefits, and the business integration into the corporate structure to support and manage corporate policy implementation. While a significant number of EMRS projects have been conducted using the traditional individual mill approach, a corporate driven deployment and implementation initiative has improved the deployment cycle and project benefits. In general the typical results for a normal EMRS im-plementation are:
1. Typical pay back of small projects in less than three months, one year for large projects.
2. A reduction in Green House Gas emissions from reduced fossil fuel usage.
3. Improvements in system reliability to avoid lost production time.
4. Multiple opportunities to find savings opportuni-ties through the powerhouse assessment process.
EMRS implementation under a corporate organiza-tion provides a variety of addiorganiza-tional benefits to the client and implementation teams.
1. The standard integration of corporate policies into the EMRS system rule sets to comply with contracts and provide reports and status into the corporate dashboards and email distribution sys-tems.
2. The EMRS Assessment and Implementation teams become an extension of the corporate of-fices. This results in EMRS applications team responsive to the corporate planning and report-ing processes to meet company objectives. 3. The powerhouse assessments become a standard
fleet evaluation tool. This permits corporate planning a more accurate listing of opportunities in an environment that includes all the effected departments.
4. There are benefits to the EMRS implementation teams. Corporate support results in proper sche-duling, elimination of duplicate effort, and uni-form project implementation resulting in a higher degree of success.
REFERENCES
(1) Ronald L Childress; Department of Energy; Energy Efficiency and Renewable Energy - Best Practices; "Closed-Loop Energy Management Control of Large Industrial Facilities";
http://www1.eere.energy.gov/industry/bestpractices/pdfs/steamdigest2002_closed_loop.pdf
(2) Dan Bamber, Ronald L Childress, James E. Robinson; Rule-Based Energy Management and Reporting System (EMRS) Applied to a Large Utility Station Complex; Energy Engineering, Volume 102, Issue 3 May 2005, pages 43-62;http://www.informaworld.com/smpp/content~db=jour~content=a913274124~frm=titlelink
(3) Robinson, J. E.; Moore, D. A.; "Audits and Implementation of Plant Wide Energy Management and Reporting Systems"; Industrial Energy Technology Conference; Energy Systems Laboratory (http://esl.tamu.edu); New Or-leans, LA 2006-05;http://repository.tamu.edu/handle/1969.1/5639
(4) Robinson, T. J.; "A Novel Approach for Estimating Energy Management and Reporting System Benefits Using Mill Historical Data"; Industrial Energy Technology Conference; May2011, Energy Systems Laboratory (http://esl.tamu.edu);New Orleans, LA 2011-05
(5) Robinson, J. E.; Robinson T. J.; "Forecasting and Capturing Emission Reductions Using Industrial Energy Man-agement and Reporting Systems"; Industrial Energy Technology Conference, May2010, Energy Systems Laboratory (http://esl.tamu.edu), New Orleans, LA 2010-05
