Peak Demand Control for Industry

It has been proven for many years that the there are three key areas that can save industry money on their power bills.  First is retrofits of inefficient equipment and lighting, second is making sure your on the best tariff or have the best possible electricity purchasing scenario for your company and lastly managing your peak demand.

Peak demand control is critical to reducing costs because so many of today’s electricity charges are scaled by the demand level.  Back in the good old days, the demand charge was a simple calculation of  kW or kVA peak times a fixed rate (for example  2500kw x 14.00 per kw) now there are transmission, distribution, connection and other charges that directly relate to the highest demand you have set.  In many electricity markets there are also charges for demand in the on/off/mid or shoulder peak periods too.

A misconception regarding demand is that it is an instantaneous occurrence, in other words, people think that if the demand in the facility goes from 1500kw to 1800kw for even a few moments, that a new peak demand level will be logged by the utility meter. This is not true.  Peak Demand is calculated over a period of time which is defined in your utility tariff or electricity purchasing agreement.  Typical measurement periods for demand calculations are 5,15,30 or 60 minutes.  Some markets even calculate the values on a rolling window to make it more difficult to reduce your overall peak.

When you decide to manage your peak demand using a computer system it is critical to know when each measurement period is starting, without this information you can never correctly calculate the peak demand the way the utility does.  Once the computer software and the utility meter are in sync, then you have the power to control your peak demand to a level of your choosing.  

In order to avoid setting a new peak for your facility it is necessary to choose a target level that you wish to operate to and then have the computer software read the utility meter data and then predict where the kW or kVA load will be by the end of the current time interval.  When the Energy Management Software predicts that the target will be exceeded, then the decision is made to begin to curtail pre-selected loads in the pre-determined order to ensure that by the end of the interval the peak target is not exceeded.

This all happens automatically and efficiently and the end result is savings on all the charges that relate to your peak demand.  Of course you have to have equipment within your facility that you are willing to control in order to curtail the electricity load when it is necessary to do so.  With the rising costs of energy, it is no longer a question of if something can be controlled but at what cost saving it is worth while to control.

In most areas, Industry have not exploited the opportunities to save on electricity charges through this peak demand control method.  This may be due to lack of understanding of the principles behind peak demand management or a lack of knowledge regarding how to get this type of Software installed and working. At LCA Energy Management Solutions, we are ready to help you deploy a peak demand control system that will generate virtually instant monthly savings.  We provide training, startup and ongoing technical support services.

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Meter it

In order to control peak demand and save money, it is important that the Software you choose to be able to read the on-site utility meter(s) on a minute by minute basis.  This means either communicating directly with the meters or having pulse metering signals made available to bring into data acquisition equipment (DAQ).  If the facility is supplied with electricity by more than one meter then all supply meters will need to be included in the data collection. The Energy Management Software will either talk directly to the meters or the DAQ and centralize the data at the computer.  In the case of multiple supply meters, the software must be able to add or totalize the meters in order to get a “Facility Total” consumption reading on a minute by minute basis.

Control it

In order to control loads within the facility and save money, the Software must be able to take the Total Facility load and compare it to a Peak Demand Target  or  Hourly KWh target.  When the forecasted demand or consumption is predicted to exceed the set targets, the Software must then reduce the load according to the “Curtailment Strategy” that you have configured.  The Curtailment Strategy will decide what loads are shed, how much and in what order. 

The Sofware you choose should also support multiple curtailment strategies so that you can choose different scenarios based on production requirements or based on whether you are activating the strategy based on peak demand targets, hourly kWh targets, a Demand Response Signal or a Target Price point (a electricity price threshold)

Confirm it

It is also important that the Software have the ability to generate reports that clearly indicate savings, curtailment events and Demand Response Compliance.  Multiple users should be able to access the information in a timely manner and to be able to generate reports that clearly show DR compliance, Peak Demand Control Savings, load profile changes and savings achieved through electricity price based curtailment.

Versatility and expandability are also important, both in terms of configuration and being able to add additional meter(s), sub-metering and control points.  So be sure you can expand as your requirement change over the coming years.