Have noticed it takes a few e-mails before most South Africans get around to a response.
Not very good communicators, for some odd reason.
Have noticed it takes a few e-mails before most South Africans get around to a response.
Not very good communicators, for some odd reason.
In search of South African Technology Nuggets(R), for sale & trading in South East Asia.
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desA (02-Mar-10)
This link will give interesting facts on solar.
however it mentions the South African Central Energy Fund (CEF) maybe they have a figure for you of the number of geysers.
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I don't know how accurate you need your answer but from the WHITE PAPER
ON RENEWABLE ENERGY November 2003
So 32 846 GWh per annum (8760 hours) = 32 846 000 000 kwh per year total residential consumption.Solar Water Heating: Domestic solar water heating is currently about 1.3% of the solar energy market. Residential consumption of electricity in 2000 amounts to about 32 846 GWh (2.83 Mtoe). Assuming that some 30% of total domestic electricity consumption is used for water heating and that 60% of this electricity can be replaced by solar energy by using a hybrid solar-electric water heating system, then the potential savings for urban residential households come to 5 900 GWh (0.508 Mtoe) (Fecher et al, 2003). This is about 18% of urban residential consumption which is equivalent to a large coal-fired power station (900 MW). There is thus considerable scope to increase the application of solar water heating,
If as they say 30% is water heating then 9 853 800 000 kWh is water heating load.
This is where the assumptions begin but lets assume that every geyser is on average 3.5 kW and it's actually heating for 5 hrs each day, then its consumption will be 17.5 kWh of power per day. Equates to 6387.5 kWh per annum.
Divide 9 853 800 000 kWh total water heating load by 6387.5 kWh per geyser and it gives you the number of HWC's as 1 542 669 in total.
Add to this that the number of HWC's might be increasing at 5% per annum and the figures were from 2003 then in 2010 it would be nearer 2.17 million cylinders.
There's several areas for inaccuracies in this figure. Firstly Eskoms initial hot water load estimates could be bulls**t, secondly the average geyser power was something I pulled from thin air working on the principal that a 4 kW geyser is the cheapest to purchase so the majority will be 4kW, thirdly the annual increase in the number of homes with hot water is only increasing at 5% per annum. If the innacuracies all compound in one direction then I wouldn't be surprised if this figure is 20% off the mark.
Last edited by AndyD; 03-Mar-10 at 03:28 PM.
desA (03-Mar-10)
Thanks so much. I owe you a few cases of your favourite beverage. Stunning work.
Ok, let's work in the following:
1. SA geyser elements are generally designed on a 3.5h recovery, from cold to hot - based on the geyser element kW & volume.
2. The new geysers will factor in:
2.1 New homes
At 5% growth p.a => 108 500 to 166 058 new HWC's pa;
2.2 Replacement geysers.
At say 10 year lifespan, annual replacement ~ 217 000 to 332 000 p.a.
At say 15 year lifespan, annual replacement ~ 144 667 to 221 333 p.a.
3. New geysers p.a. ~ 253 167 to 387 391 p.a (conservative estimate, 15 year lifespan) / 325 500 to 498 058 (10 life span)
I've worked these into your figures above. We can bat these around further, if you're keen. I hope my calcs are in line.
Looks like a good business to be in.
In search of South African Technology Nuggets(R), for sale & trading in South East Asia.
I think your life expectancy figure of 15 years might have been accurate with the old copper cylinders.
The new galv cylinders with the annodic protection are lucky to last 6-8 years. The problem is that nobody, and I mean nobody ever replaces the annodes every year as specified by the manufacturers. The annodes are sacrificial and once erroded the cylinder starts to corrode rapidly.
A perfect example of built in obsolescence if ever there was one.
^ A very valid point. Thanks for that.
Exactly, who ever thinks to maintain their geyser. No wonder the big geyser manufacturers are building larger factories. Food for thought.
I saw in your quote, this nugget:
Did this estimate materialise?Assuming that some 30% of total domestic electricity consumption is used for water heating and that 60% of this electricity can be replaced by solar energy by using a hybrid solar-electric water heating system,
In reality, what would the solar percentage of the total geyser market be?
What percentage of the market would move over to a heat-pump, if these were reasonably priced, affordable & with a lifespan longer than the geyser itself? Expected energy savings around 70-80% on water-heating.
In search of South African Technology Nuggets(R), for sale & trading in South East Asia.
If you would like some bedtime reading you can try these;
24-market-survey-of-swh-in-sa-final-report
AN HISTORIC OVERVIEW OF CONTROLLING DOMESTIC WATER
HEATING
Market Survey of Solar Water Heating in South Africa
DOE Solar Water Heating Plan/Framework
DEMAND CONTROL UNIT SUPPORTING THE NEW DUAL ELEMENT HOT
WATER SYSTEM
If you're after some specific publication or report/whitepaper try a few strings to focus a google such as 'intitle' and"index.of", you'd be surprised what's not tied down on many of the servers.
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