city was also investigating ways in which existing households could be offered financial incentives to switch to solar geysers.

'It's going to be an interesting task for us to try'
"I don't think people realise the impacts that renewable energy and energy efficiency across the city and in most parts of South Africa, can have in changing the energy recipe and providing jobs," he said.

Another speaker, Trevor Govender of the Department of Minerals and Energy's renewable energy branch, said fitting solar geysers to all commercial buildings and homes - where technically feasible - would save eight percent of South Africa's total energy consumption.

The use of solar geysers could provide 23 percent of the government's energy savings target of 10 000 gigawatt hours by 2013, he added.

And a solar geyser could save an individual home as much as 30 percent to 40 percent of its energy bill - although there was the "unfortunate" problem of the high initial cost of such heaters, Govender said.

Asmal said Cape Town had 10 percent targets for both the number of city households to be fitted with solar geysers and for renewable energy as a percentage of the overall energy consumption, both by 2010.

"That target (renewable energy) is part of the statutory IDP (integrated development plan) and so is established in law," he pointed out.

The city's housing stock was somewhere in the region of 800 000 to 900 000.

"So we're looking at 80-to-90-to-100 000 houses being fitted with solar water heaters.

"Now that's a fairly ambitious target.

"Recently one of our partners reminded me of what that target meant, and it threw me back a little - it means putting in 1 000 solar water heaters a month!

"That's ambitious, and it's going to be an interesting task for us to try and pull that off."

But the project potentially provided a major economic development boost, he added.

"From a conservative calculation just on that 10 percent target, R1-billion will come into the economy with those solar geysers.

"That will be a fairly significant investment and it gives us the opportunity to set up the industry."

Although the city would not itself finance the fitting of solar geysers, there were various ways in which this could be done, Asmal said.

Among others, the city had held initial discussions with Absa Bank, and Eskom's demand side management fund and the government's central energy fund could be tapped.

Also, the CDM (clean development mechanism) fund that is part of the Kyoto Protocol on climate change could be used to provide financial incentives to switch to the cleaner and renewable energy option offered by solar power.

Although the draft by-law would make it compulsory to fit solar geysers in new buildings, the city would promote the use of incentives, Asmal said.

"We'd certainly like to go the incentive route rather than the stick route."

And the city would also look carefully at how solar energy could be used in other areas - notably the desalination of seawater, which has very high energy requirements.

From a straight financial viability point of view, calculated in terms of traditional economics, fitting solar geysers was probably financially unsound, Asmal conceded.

"But we need to look at this in broader terms of full environmental resource economics, and factor everything into the costs.

"We are now starting to pull together a number of these solar water heating initiatives, and we're getting an actuarial scientist in with Sustainable Energy Africa and other partners to factor that and to work out the financial flows and modelling of the whole process."