2. a change in price; 3. a demand response event. Often, a balanced approach that in- corporates two or more of these items will be more easily implemented, as the return on investment of effort and automation is greater. While controlling demand manu-


ally can achieve energy savings, for some facilities the use of demand control systems can assist in the effort. These systems use real-time information and computer-con- trolled algorithms combined with user-defined rules and automation to manage electricity loads. The goal of the software is to realize the electricity savings without producing fewer castings and protecting sensi- tive processes. No matter what method or methods


of demand control a manufacturer employs, the process begins with data collection. Real-time data directly from the utility meter is critical for understanding the minute-by-minute activities on your production floor and reproducing the exact formula utilities use to calculate demand


charges. These are both necessary for accurate predictions of demand spikes and delivering the correct amount of energy curtailment to each piece of equipment you operate. With this real-time information, cur-


tailment requirements are calculated by using a predictive model that accounts for volatility in usage within each inter- val of energy usage. The model should be fine-tuned to address specifics about your facility and its processes. Once calculations are completed, all


available loads should be evaluated and categorized for reduction. This is done in part with rules that are pre-defined by the plant operators to take into account processes, production requirements, time of day or any other parameters deemed critical. Once a demand control system


determines the particular loads to be curtailed, usage can be reduced by the exact amount necessary to meet the objective. In the case of peak de- mand control, loads often only need to be curtailed for a few minutes to avoid a costly spike. With demand response, curtailment can be much


longer, usually two to four hours. One curtailment strategy is “rolling curtailment.” Traditionally, for longer periods of curtailment, plant operators would identify three or four large loads and shut them down for the entire length of the event. With rolling cur- tailment, connection is made to many loads, and a load shedding scheme is implemented that uses combinations of smaller actions that, in the end, have less overall system impact but reach or even exceed the curtailment levels desired. Once curtailment has concluded,


the reduction should be confirmed using data from the meter. Savings should then be verified and docu- mented. These reports can provide insight into sometimes previously obscure energy activities and can aid in better decision-making. This information can be shared throughout the company and often leads to other energy-savings measures.


MC For More Information


“Turn Down the Heat,” R. Murillo, MODERN CASTING, September 2006, p. 30-33.


Identifying Demand Control Savings


Opportunities at Your Site T


o determine your facility’s potential savings, you should:


1. Understand the peak demand charges on your utility bill.


2. Ask your utility provider for available demand response programs.


3. Analyze your energy load profile data (15-, 30- or 60-minute interval data).


4. Determine how much load is available for curtailment.


5. Determine curtailment rules to protect production.


6. Calculate projected savings/revenue. 7. Contact utility for possible incentives. 8. Capture all project costs, including hard- ware, software (if used) and installation.


9. Identify additional system benefits, such as sub-metering, load monitoring and data logging.


10. Calculate the return on investment. 34 MODERN CASTING / December 2010


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60