Little white box signals end to summer blackouts

A little white box—a small, low-cost switching device fitted into low-priority home services such as air-conditioners—could signal the end to Australia’s inconvenient, costly and dangerous summer blackouts during peak demand periods on extremely hot days.

Designed by Australian firm Saab Systems, and currently commencing a second trial in around 2000 homes in Adelaide, the switching device is part of the revolutionary Saab Direct Load Control System (DLCS).

According to David Ledger, Civil Systems Manager, Saab Systems, on hot days the average demand of air conditioned dwellings more than doubles, at a time when electricity network capacity is lower. In these situations parts of the grid can become overloaded, which results in a blackout,” says Ledger.

Rather than building costly infrastructure to meet this fast-rising peak on just a few very hot days Ledger says the DLCS is a simple, no-cost-to-the consumer, way of saving energy and keeping electricity costs under control.

The DLCS can be fitted into power hungry home services such as air-conditioning, pool pumps, hot water systems and spas. The device allows electricity distributors to remotely switch these services off for very short periods during peak demand times. While the switch off time is kept short, so that there is no impact on the performance of these home services, the cumulative effect over a large number of houses produces a major reduction in grid power consumption.

“Turning off domestic air conditioners for just five minutes every hour during a peak demand period in around 100,000 homes can drop a city’s energy load by around 10 per cent—which is sufficient to avoid blackouts on very hot days,” says Ledger.

For air-conditioner installations, the switch only turns off the air-conditioning compressor, leaving the fan running and allowing cool air to circulate. Early trials to ascertain if home owners were inconvenienced by this technique showed there was no change in their home’s comfort level and they were not even aware of when the device was activated.

According to Saab Systems, the Direct Load Control System has the potential to minimise escalating energy bills around the country and has many other applications. Ledger says State energy companies have also expressed interest in using the Direct Load Control System for off-peak hot water control.
Saab’s innovative white box is a win-win solution. Home owners maintain normal levels of air conditioning while avoiding blackouts; energy companies can end overloading of the network; and everybody benefits by the reduction in spiralling energy costs.

The Australian Greenhouse Office has begun talks with Standards Australia on a draft standard to stipulate all new air conditioners sold in Australia have demand management capability.

1 November 2006