Defence firm has solution to blackouts

One of Australia’s top ten defence systems firms, Saab Systems, has used its military expertise to devise a low-cost system that could provide a long-term solution to the problems of power management and signal an end to Australia’s inconvenient, costly and dangerous summer blackouts during peak demand periods.

The revolutionary Saab Direct Load Control System (DLCS) is designed around a small, low-cost switching device fitted into low-priority, power hungry, home services such as air-conditioning, pool pumps, hot water systems and spas. The “little white box” receives data via FM radio transmissions, allowing electricity distributors to remotely switch these services off for very short periods during peak demand times.

According to David Ledger, Saab’s Civil Systems Sales Manager, the switch off time is kept short, so that there is no impact on the performance of these home services, but 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.

Saab’s innovation would permit the equitable control of nominated domestic systems and remove the need for widespread mandatory restrictions.
For air-conditioner installations, the switch only turns off the air-conditioning compressor, leaving the fan running and allowing cool air to circulate. 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.

Ledger says 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.

“Rather than building costly infrastructure to meet this fast-rising peak on just a few very hot days, the DLCS is a simple, no-cost-to-the consumer, way of saving energy and keeping electricity costs under control.
“The system can also be programmed not to inconvenience high priority users such as the sick and elderly,” says Ledger.

Saab’s innovative white box is a win-win solution. Home owners maintain normal levels of air conditioning while avoiding blackouts; energy companies can avoid 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.

19 January 2007