Energy saving - a piece of cake..

Information from an energy monitoring system was key to success for a recent energy saving campaign at McVities Cake Company.

Parent company, United Biscuits launched its National Energy Awareness campaign "Switched On" initiative in 2001, as part of its continued commitment to care of the environment, with the objective of reducing energy consumption by 13% across its eleven factories by 2009.

A special "HEAT" team was formed at the Halifax site to implement the campaign and develop several energy saving projects. The team quickly identified that they did not have the ability to measure the electricity used in different areas of the production facility or the offices. Understanding that "If you can't measure it you can't improve it" they looked for a cost-effective solution that would provide the information they required.

Following discussions with ISS Ltd of Ilkley a monitoring system was developed based on Prodigy industrial automation software. Twenty mains supplies provide electricity across the site from a central electricity sub station. Special split core current transducers were used to monitor each supply. These give 4-20mA output directly proportional to the current and simply clip on for ease of installation. They are connected via an Adam 5000 unit and RS 485 link to the PC based Prodigy system in an office 200 yards away.

The system provides a continuous record in real time of the electricity consumption across the site. Both instantaneous and daily cumulative demand is plotted and trends of combined, individual or grouped supplies can be viewed on the system monitor. Powerful trending facilities make it easy to see patterns and spot irregularities in power consumption. Historic trending quickly highlights changes in demand caused by different operating procedures or energy saving initiatives. Trends can also be printed out daily, weekly, by shift etc. or on demand as required.

By using the system the HEAT team quickly identified the main areas of energy usage to focus attention upon. During 2001 this led to a reduction of 15% in the kWhs of energy used per tonne of product produced. The pay back period for the system was calculated to be only six months. Following this success it is intended to expand the system in 2002 to include monitoring the usage of gas, effluent and water.

ISS Ltd. supply Prodigy monitoring & control systems as well as instrumentation to industry across the UK. For more information telephone 01943 602001 or email This e-mail address is being protected from spam bots, you need JavaScript enabled to view it