Background

The Utility Load Manager (ULM) is a Patented Smart System that enables Smart Grid functionality on the Low Voltage Network. The primary use of the system was to segregate and ensure control at the residential level. This would enable National Control to control the residential load and prevent load shedding in the economically active sectors.

It was projected that between 2000MW off peak and up to 6000MW during peak could be controlled and taken offline in case of a load shedding necessity.

Large Scale Pilot Rollout

• The ULM was developed, manufactured, and rolled out in 27000 residential houses.
• This sample signified a representation of the whole residential market (excluding lower LSMs)
• Teams were deployed to interview and test the customer reactions to the new product and its purpose during load shedding. Effectively the residence would be load limited and prevented from using more that a prescribed amount of power during the load shedding period.
• The skills needed to gather the customer data, the network information, the profiling data etc. was all tested and proven in this project.

Results: Key findings and inferences

The following key findings are relevant from the pilot studies:

• Load limiting provides control of demand in residential homes and provides 40% more power that appliance control (geyser control). This is because appliance control typically focussed on an appliance and not the whole house (Based on University of Stellenbosch M&V audit report Nov 2009)
• Unlike Appliance Control and timers that are currently being employed, the load limiting devices cannot be easily by-passed, as this will be detected and can be rectified. With Appliance control devices such as ripple control and timers, a steady degradation in the benefits will be noticed.
• Load limiting is much faster and easier to roll out as NO home intrusion is required (Based on University of Free State CDS ULM report April 2010)
• Full Virtual power station attached to the system, this gives a real time view of the power consumption at any point in time and the reduction is demonstrable. This can be measured and verified through the system backend. (Based on University of Stellenbosch M&V audit report Nov 2009)
• The Display unit issued is collected from the utility and synchronised with the field device on connection to the homeowner’s plugs. Hence no home intrusion is required.
• Residential home owners embrace Load Limiting in the face of blackouts. The Load limiting methodology was developed as an alternative to Blackouts and as a partnership between the residential home owner and Utility. (Based on University of Free State CDS ULM report April 2010)

The system overview: