Tropical technology

TROPICAL Australia can show the way to city dwellers in the use of new energy-saving technology being developed by a member of the team at the Murdoch-based Australian Co-operative Research Centre for Renewable Energy (acrcre/acrcre.html">ACRE).
Associate Professor Dean Patterson, of the Northern Territory University, is working on several projects that could provide major savings in energy costs.
In one, new magnetic materials and other developments will reduce the cost of operating a ceiling fan by at least 90 per cent. A small item?
Not in a city like Darwin, where it has been estimated that, during the afternoon, home ceiling fans use more power than any other appliance.
Wet Season
In the wet season most homes will have several running 24 hours a day.
Professor Patterson, an electrical engineer, points out that the new generation of fans could also reduce capital costs in remote areas (an unusual situation -- most renewable energy technologies at present involve high initial costs, but low operating costs).
He cites the example of the photovoltaic panels that would be installed on a house in a remote com-munity to provide the electricity for a fan.
At present such panels would cost $1000. The new generation of fans, requiring a tenth of the power, would need a panel costing only $100.
Professor Patterson explains that his project, as part of the ACRE programme, is driven by the fact that in providing the benefits of electrical energy, we seek to minimise the direct conversion of energy to low-grade heat, from whence it is no longer useable for the benefit of the community.
He points out that there are two separate, but related aspects which direct the work of his programme:

: The use of renewable energy is severely limited at present, principally because of its cost.; Thus there are economic and social pressures not to waste this expensive energy in any conversion process before it can be used.; Current levels of technology in rotating machinery allow important increases in the efficiency of mechanical/electrical energy conversion. This is the rationale behind efforts in the wind-generation work of the CRC (ACRE).

: Energy use, again driven by a desire to minimise wastage, or direct conversion of energy to low-grade heat.; This aspect has an initial focus for applications in remote areas, where the higher energy costs provide a stronger motivation to reduce waste, and to pay more for more efficient equipment.

Synergy
Professor Patterson says it is the intention of his research group to exploit the synergy resulting from being able to allocate development costs to remote arid areas.
The resultant experience should enable the researchers to present, at a more reasonable cost, high efficiency equipment for use in cities.
The subsidiary focus should present the CRC with a very real opportunity to significantly reduce national greenhouse gas emissions.
Professor Patterson says that as a result of developing awareness of the importance of demand-side management in any serious attempt to limit the global impact of energy wastage, and given the expertise available, his group had expanded its programmes.
These now include an area where significant inroads can be made, in energy management and use in buildings, in temperate, subtropical and tropical conditions.
It is believed that these two areas of research, electric machines and buildings, can give the CRC its opportunity to make a significant contribution to greenhouse gas reduction.
The next step in technology
Some of the technology Professor Patterson believes is within our reach:

Variable speed electrical generators for wind turbines without gearboxes, arid tidal power generators with minimal gearboxes, achieving efficiencies above 95 per cent at the 20kW level.
Economic power electronic interfaces between such generators and a power supply system with efficiencies above 97 per cent at the 20kW level.
Economic, small and efficient magnetic components in the generator structures, and in the power electronics, both in this programme and in the power-conditioning programme.
A range of small electric motors with efficiencies above 80 per cent, compared to the present 50 per cent, for direct application in, for example, ventilation systems, addressing greenhouse gas abatement through demand-side management.
A range of active and passive solutions to dramatically decrease the wastage of energy in buildings, commercial and domestic, in construction and operation, in temperate, subtropical, and tropical climates.