In today's ever-changing economy, companies across the country are striving to lower operating costs and trim their budgets. As a result, an increasing number of businesses are starting to pay more and more attention to their utility bills as well as how energy conservation and allocation methods can affect the bottomline.
A good start in making a concerted effort to cut utility costs is to first learn more about your local utility rate structure and the major cost components within it: kilowatt-hours (kWh) and kilowatt demand (kW). After which, the next step is to find out how, where, and when all of the power is being consumed beginning with the main service(s). However, most utility bills only furnish line items of the amount of units of energy and demand consumed during a specific billing month.
By utilizing submetering equipment, companies can accurately pinpoint how, where, and when their facility is consuming power, thereby uncovering specific problem areas within an organization that potentially may have gone undetected.
After taking a good hard look at its utility bills, a foundry located in New Hampshire recently decided to invest in submetering equipment.
At first glance, the foundry's demand profile (shown in the figure below) may not be recognizable as a $138,500 utility bill, but that's exactly what it represents. Now, by reviewing the demand profile provided by the computerized energy monitoring system, the foundry can see how and when it is using energy and whether or not there is any chance of saving peak demands or excess kWh. A closer look at the graphic reveals the 250kW spike toward the end of the month, which has increased the monthly bill by $2000.
With an ECA (External Contact Adapter), end-users can now incorporate anything with an external pulse or dry contact into the automatic meter reading and data logging system. In this case, it was the KYZ contacts furnished by the local utility, but it could just as easily have been pulses from a gas, water, steam, compressed air, chilled water, or BTU meter.
To further complement the ability to see how the overall site was consuming power, additional submetering equipment was installed to find out exactly how much it cost to operate the facility (the foundry operations were being assessed 60% of the utility bill because all of the equipment and furnaces were electric).
The initial meeting and walkthrough with both the accounting and foundry personnel took less than 2 hrs. Within two weeks after receiving the purchase order from an electrical distributor, the submetering equipment selected for the project was shipped and installed. And as part of the software and startup package, factory personnel were on-site to checkout the final connections, load in the software, and teach the customer how to use the system.
This first month's data proved the original assessment of the foundry's electrical use incorrect. By using submetering equipment to obtain specified meter readings, the foundry staff was able to compare their own consumption of kWh and kW against the main service. After doing so, it was established that the foundry represents 39.8% (500,344/1,256,164) in kWh use and 44.4% (1,880/4,228) in kW demand. According to the local utility rate structure, the foundry operations only account for 40.4% of the overall utility bill, as opposed to the assessed 60%. This information alone increased the foundry operations profitability by $27,000 a month.
In addition to learning the true cost of the foundry operations, further demand profile analysis of its submetering equipment has shown that its operations were responsible for setting the peak demand for the overall facility. More in-depth investigation of the foundry submeters revealed the specific department (Pattern Shop) responsible and more importantly how many times it occurred that month. Correcting that situation alone has eliminated $2000 worth of demand charges each month resulting in the payback of the equipment and installation in less than five months.