At Gateway Theatre of Shopping in KwaZulu-Natal, energy tariffs skyrocket when power consumption exceeds the notified maximum demand (NMD). Since August 2011, however, power consumption has been closely monitored and managed, a move that will save property owners Old Mutual Property (OMP) a considerable amount in energy costs per annum.
Gateway is one of the most prestigious shopping malls in South Africa with 150 000m2 of general letting area, almost 400 shop fronts, and 24 million people per year passing through its doors. The centre faces the same energy costing challenges as any large facility in South Africa where Eskom’s NMD tariff rules are in force – if the centre exceeds notified maximum demand, the facility is charged a premium on power usage.
Notes Ken Davidson of the Property Investments division of OMP: “Maintaining a cost effective ‘green’ facility is non-negotiable criteria for OMP as one of the leading property management groups in South Africa and a founding member of the Green Building Council of SA. With the implementation of this energy monitoring and management solution, one of our most important long term goals – a key driver of the R6 million integrated intelligent building automation strategy launched at the Gateway centre in 2009 is being realised.”
The power management solution has been made possible through better exploitation of the automation capabilities and embedded energy management solution within the Johnson Controls Metasys Building Management System (BMS) installed at the centre.
The challenge; the solution
Ian Hargreaves of Johnson Controls describes the challenge faced at Gateway: “Eskom defines highest averaged demand as the highest measured kVA or kW during any 30-minute integrating period within a designated billing period. If this average is higher than the notified maximum demand, the facility is charged a premium on usage. To adequately manage its consumption and utility bill, the facility thus needs to measure power usage in real time and act quickly to keep usage in peak periods below the maximum.
“We have been able to do this by integrating a Panel Track Energy Metering System to the shopping centre’s now upgraded and IP enabled Metasys building management system,” says Hargreaves.
The Panel Track system meters eight defined ‘rings’ or streams of energy consumption at the facility. That information is fed into the Metasys BMS which has been configured to trigger load shedding activities when defined maximum use thresholds are reached. Load shedding is done by shutting down power hungry non-essential equipment like the two Carrier Screw Chillers, two Carrier Centrifugal Chillers and 3 Trane Centrifugal Chillers with Pumps and Cooling Towers at the shopping centre that can pull up to 8mVA when working at high capacity.
Says Hargreaves: “We will continue to refine the solution to optimise load shedding and power usage, while at the same time meeting the changing needs of tenants and shoppers in the mall.”
For both Johnson Controls and OMIG the energy management solution is a flagship solution. Says Rowlands: “This is the second energy management solution that the OMIG has implemented with Johnson Controls, the first being at the Menlyn shopping centre in Gauteng. We hope that it will serve as a showcase to other property owners, incentivising them to also implement technology enabled green strategies – it’s an investment that is certainly beginning to pay off for us.”
About Johnson Controls
Johnson Controls is a global diversified technology and industrial leader serving customers in more than 150 countries. Our 142,000 employees create quality products, services and solutions to optimise energy and operational efficiencies of buildings; lead-acid automotive batteries and advanced batteries for hybrid and electric vehicles; and interior systems for automobiles. Our commitment to sustainability dates back to our roots in 1885, with the invention of the first electric room thermostat. Through our growth strategies and by increasing market share we are committed to delivering value to shareholders and making our customers successful. In 2011, Corporate Responsibility Magazine recognised Johnson Controls as the #1 company in its annual “100 Best Corporate Citizens” list. For additional information, please visit http://www.johnsoncontrols.com.