Interval Data

Interval data is one of the most powerful tools available, yet very few plastics processing sites actually get it or know what to do with it. Not only does it give you time-based information on your energy use, it’s generally free.

Your energy supplier collects data on how much energy you use every 10, 15, or 30 minutes (you can see this if you go to the main meter and look for the connection). They do not collect this for your benefit; they collect it so that they can bill you for energy use.

However, this data is very valuable to plastics processors. It allows you to look at your energy use every interval and to see when you are using energy. This is particularly important for looking at start-up, shut-down, and holiday usage, or use at any time when the site is not fully operational.

This data is even more valuable when a site has several meter points. The interval data then becomes almost like submetering for free!

Actions:

Get the interval data from your supplier. They’re already collecting it and will send you a large spreadsheet file.
The data will be in spreadsheet format (generally CSV). Convert this to your preferred format and start looking at the data. Add up daily use, look at daily profiles, and look at times when the site is not fully operational.
Look especially at start-up times, shut-down times, and energy use over holidays. Using interval data will allow you to see when machines were turned on or off.
Above all, use the free data

Note: Dr. Robin Kent is the author of Energy Management in Plastics Processing, published by Plastics Information Direct, and managing director of Tangram Technology Ltd., consulting engineers specializing in energy management in plastics processing. rkent@tangram.co.uk.