Solar Water Heaters: What you need to know

[BCO]

Hi guys,

I've received a few PMs from forumites who know that I have a solar water heater and had some questions (particularly about the upcoming subsidy) for me, so I thought it'd be better just to share this knowledge in a dedicated thread. Here goes:


Don't confuse a solar water heater with a solar (photovoltaic) panel. Solar water heaters do NOT generate electricity, they literally heat water directly with the sun's energy and store it in a highly insulated tank.
Many solar water heaters also include an electric element just like a conventional geyser and if there's insufficient solar heating going on, they switch to electric. Also, some come with gas heating as an optional extra.
Solar water heaters are going to be subsidised by Eskom. The end user does not have to worry about having to deal with sorting out the subsidy themselves. Retailers will sell users the water heaters at the subsidised price and the retailer will claim this subsidy back from Eskom. Just as a side note, Eskom has contracted Deloitte to handle the subsidy process.
The subsidy process has not yet come into effect. As of today (29-01-2008) I was told that there are still 3-4 weeks to go before it comes into effect. One of the main reasons for this is that the subsidised amount is being disputed by the industry. I was part of the pilot project, and during the pilot, end users received a R6000 rebate. Currently Eskom wants to offer between R3k and R5k, and the solar water industry in SA feels that this amount is too low.
If you want information about the Eskom subsidy, I suggest you speak to solar water heating companies rather than to Eskom. The solar water companies are much smaller and more likely to help out individuals with information than a big juggernaut like Eskom is.


My solar heater was supplied by Solahart (http://www.solahart.co.za). I went with them because apparently they're the only SABS approved solar water heaters in SA. That's not to say they're the necessarily best, and it would be quite interesting if other existing or possible future solar water users could post their make and supplier in this thread.

I've been extremely happy with my heater - especially since it survived a massive hailstorm in JHB a few months back with no damage. I never have a problem with water not being hot either.

Finally, much of the info above was provided by Jim at Solahart, so it should be fairly accurate. Also, I have no professional affiliation with any solar water heating company.

[Syndyre]

So do you run off just solar with no electric backup and you always have hot water?

[BCO]

No, I have electrical backup in my solar heater. Gonna try a little experiment for the next couple of days and turn off the heater on the distribution board just to see what it's like with solar only.

[ghoti]

With your 6k rebate, how much did it end up costing you? IE, with the subsidy could you pick up everything for almost free? or how much are you as an individual looking to put in?

[BCO]

Even with the rebate they're quite expensive. Mine cost me R14000.00. I'm pretty sure that there are cheaper units than the Solaharts though.

[Alan]

Even with the rebate they're quite expensive. Mine cost me R14000.00. I'm pretty sure that there are cheaper units than the Solaharts though.

That is pretty steep :(

[Geoff Ogden]

Wow

Just phoned the PE contact and he tells me R21 000-00 for a small unit (family of 2)

[BCO]

Mine's a 180l unit (used by 3 people) and its pre-subsidy price was R20k.

[Syndyre]

No, I have electrical backup in my solar heater. Gonna try a little experiment for the next couple of days and turn off the heater on the distribution board just to see what it's like with solar only.

Be interesting to see, although that's the best system, solar can heat it as far as possible and there's still an element so you never have no hot water.

[ToxicBunny]

I'm sorry but even a R6k subsidy on a R20k unit is not good enough.

It needs to be able to pay off in tops 5 years I feel. Eskom want us to use these things, they must make it as attractive as possible tbh.

I like the idea, but I don't like the idea of shelling out R15k(+-) on a unit.

[Robin Hood]

I'm sorry but even a R6k subsidy on a R20k unit is not good enough.

It needs to be able to pay off in tops 5 years I feel. Eskom want us to use these things, they must make it as attractive as possible tbh.

I like the idea, but I don't like the idea of shelling out R15k(+-) on a unit.

Yeah...And if you think about it, you are now paying for another man's F-up :mad:

[BCO]

You're also paying to significantly reduce your home's carbon footprint.

[rph72]

What about Solar Panels that will fill a conventional geyser? Will that be cheaper?

[BCO]

To heat a geyser with electricty provided by solar PV panels would be much much more expensive.

[oober]

To heat a geyser with electricty provided by solar PV panels would be much much more expensive.

Yes I rate you would need both solar heating + solar PV.

[rph72]

Solar heated water to be fed directly into your geyser? Pipes instead of cells?

[ToxicBunny]

BC : I know it'll reduce the carbon footprint of my home. But thats not going to sell it to the average joe on the street.

It must reduce his bills, and be affordable, and pay itself off fairly quickly.

[ghoti]

Just spoke to a friend about this, they recon on the news, that this solar heating system would only _cost_ us, 2k or 3k?

[Syndyre]

Solar heated water to be fed directly into your geyser? Pipes instead of cells?

Yeah the water's heated directly, no electricity involved.

[Syndyre]

Just spoke to a friend about this, they recon on the news, that this solar heating system would only _cost_ us, 2k or 3k?

Unless they subsidise it by 90% I doubt it.

[ghoti]

Unless they subsidise it by 90% I doubt it.

Thats what I thought, felt a little "too good to be true"

[McSack]

Just spoke to a friend about this, they recon on the news, that this solar heating system would only _cost_ us, 2k or 3k?


Must've been SABC news :rolleyes:

[BCO]

As I said earlier, my solar heater was one of the more expensive ones available. Maybe there are ones that retail for R10k, less a R3k - R5k subsidy would mean R5000 - R7000 per unit. I highly doubt that there will be any on the market for less than that. Having said that, if a conventional geyser sells for about 2 grand, the R3-4000 difference in capital outlay could be recouped in electricity savings over a couple of years.

@ w1z4rd - your point about saving the average joe $$$$ is very true. Speaking for myself, I did it purely for environmental reasons, but sadly people like myself are very much in the minority (see Bugatti Veyron thread elsewhere).

[ToxicBunny]

BC : Unfortunately I've seen eskom touting percentages based on how much is saved etc etc... not a fixed value unfortunately... and I think I saw between 20 and 30%

[BCO]

Yeah 20-30% of total household electricity usage sounds about right.

[bekdik]

If the top 1000 electricity users were asked by government to contribute R100million each over 3 years, tax deductible, there'd be enough to provide for a higher rebate, bigger buy in, lower electricity usage, less load shedding for the 1000.

All win.

[Freshy-ZN]

Im worried that due to the sudden demand the prices will go up thus effectively negating any rebate.

I think Eskom or the Government needs to set prices on these things or something to ensure that the vultures dont use this national emergency as a get rich quik scheme.

[EchoZA]

Im worried that due to the sudden demand the prices will go up thus effectively negating any rebate.

I think Eskom or the Government needs to set prices on these things or something to ensure that the vultures dont use this national emergency as a get rich quik scheme.

Take for example the prices of UPS'es currently...

[Freshy-ZN]

Yup....South Africa takes 'kicking a man when he is down' to the extreme.

[Impreza GT]

Guys from Suntank qouted me R16000 for a 200lit unit.

[pimal3]

How difficult would it be to build your own solar geyser to preheat water going into your existing geyser? I was thinking of some black PVC pipe lying in a shallow box covered with perspex resting on a north-facing roof. A DIY should not cost more than 1K ~ 2K.

[DJ...]

Yeah the water's heated directly, no electricity involved.

Um, what do you do in winter?

[DJ...]

Yup....South Africa takes 'kicking a man when he is down' to the extreme.

Nope, just called good business. Take advantage while the market is in your favour. You would probably be doing the same thing if you were a business owner whose main revenue stream was becoming a highly demanded product. Eskom's load shedding doesnt eliminate the supply and demand rule when it comes to setting a price.

[flarkit]

BC : I know it'll reduce the carbon footprint of my home. But thats not going to sell it to the average joe on the street.

It must reduce his bills, and be affordable, and pay itself off fairly quickly.

That's the truth indeed. I'd consider forking out R5k for a really good solar heater, but no more.

I was also wondering about this idea:


How difficult would it be to build your own solar geyser to preheat water going into your existing geyser? I was thinking of some black PVC pipe lying in a shallow box covered with perspex resting on a north-facing roof. A DIY should not cost more than 1K ~ 2K.

Wouldn't this reduce the amount of heating that your geyser does significantly? Can anyone provide some more info on doing this please? Pros, cons and details such as making the water flow?

[Freshy-ZN]

Nope, just called good business. Take advantage while the market is in your favour. You would probably be doing the same thing if you were a business owner whose main revenue stream was becoming a highly demanded product. Eskom's load shedding doesnt eliminate the supply and demand rule when it comes to setting a price.

Actually no. Id just be happy that business was booming. Wouldnt have to put prices up as volumes of sales would be in my favour.

[jls_n]

Alternative u can convert your existing geyser to make use of solar heating.
http://www.sunpower.co.za/ have all the details needed to convert your current geyser.

If the geyser is below the panel then u would need a pump to circulate the water. It seems the pump will use very little power if i remember correctly, something in the range of 40w - 60w or alternative is to install a solar (photovoltaic) panel which will power the pump during sunshine.

The quotes i've seen just for panels is around R4800 - R5000. Thats the evacuated tubes for that price.

[BCO]

Um, what do you do in winter?

In many parts of SA, the sun still shines in winter.

[AutoX]

The subsidy process has not yet come into effect. As of today (29-01-2008) I was told that there are still 3-4 weeks to go before it comes into effect. One of the main reasons for this is that the subsidised amount is being disputed by the industry. I was part of the pilot project, and during the pilot, end users received a R6000 rebate. Currently Eskom wants to offer between R3k and R5k, and the solar water industry in SA feels that this amount is too low.


Here comes another gravy train!!!

[DJ...]

In many parts of SA, the sun still shines in winter.

From what I have read here so far, it is not the sun shining that heats the water, it is the ambient temperature produced by the sun that is conducted to produce heat. Well I just dont know how the ambient temperature in parts outside of Durban during winter is hot enough to heat my geyser properly. It really is an honest question - is it really hot enough in places like Jozi where the temperature in winter often doesnt break double figures to heat my geyser? Or does the electric aspect then kick in? If so, then this is not really an efficient form of solar heating and I couldnt justify paying those prices...

[BCO]

From what I have read here so far, it is not the sun shining that heats the water, it is the ambient temperature produced by the sun that is conducted to produce heat. Well I just dont know how the ambient temperature in parts outside of Durban during winter is hot enough to heat my geyser properly. It really is an honest question - is it really hot enough in places like Jozi where the temperature in winter often doesnt break double figures to heat my geyser? Or does the electric aspect then kick in? If so, then this is not really an efficient form of solar heating and I couldnt justify paying those prices...

They don't heat water beacause of ambient temperature. They ABSORB sunlight and convert its energy to heat. This is a function of the insolation (http://en.wikipedia.org/wiki/Insolation) at a particular area. This is how water in one opf these heaters can get as hot as 80 degrees in summer

Although insolation drops during winter, there's still usable energy in the sun's rays.

[DJ...]

They don't heat water beacause of ambient temperature. They ABSORB sunlight and convert its energy to heat. This is a function of the insolation (http://en.wikipedia.org/wiki/Insolation) at a particular area. This is how water in one opf these heaters can get as hot as 80 degrees in summer

Although insolation drops during winter, there's still usable energy in the sun's rays.

OK, thanks for clearing that up.

[Alastairo]

I have just organised an installation of a panel to heat 150 litre geyser from Sunpower and the cost is R8600 installed with control panel and pump.
After looking at Eskom website and coming up with a cost of R13k (including subsidy) - I know this isn't what its going to be --- I think I got a good deal

[pieter_s]

I agree with some sort of price control or regulation, especially since it will now be a legal requirement that by 2010 we MUST have these installed.

[Albereth]

You're also paying to significantly reduce your home's carbon footprint.

What is the carbon footprint of manufacturing solar heaters?

[Albereth]

Do these things require sunlight to shine on them directly - i.e. are placed in the sun. Or will the light be good enough - if could be in shade?

Not everyone lives on the northside of the hill and quite a few like the shade of trees or has someone decided that trees need to be chopped down to let the sun shine through - and what effect will that have on the carbon footprint, trees being a good store of carbon?

Will the airconditioners be subsidised?

[BCO]

Albereth, they need to be in the sun.

Regarding the carbon cost of manufacturing a solar heater, I'm fairly sure that after its 20 year (or more) lifespan it results in a nett saving of CO2.

[Koos Custodiet]

How difficult would it be to build your own solar geyser to preheat water going into your existing geyser?

As far as I can tell, not that difficult. Or expensive. I looked at the sunpower.co.za site and their prices seem a bit steep. But then again, prices are determined by supply and demand, and the demand is high, with the (Eskom :-) supply cutting out all the time.

Take a look at
www.builditsolar.com/Projects/ WaterHeating/ISPWH/IPSWH.pdf

Koos

Edit : oh yea, what I'm planning to do : if you have a pressure geyser, you can tap the warm water pipe, run that to the solar "panel", and feed the output back into the geyser drain valve. If the panel is higher than the geyser you need a small pump to circulate. Pump must obviously be able to handle the water temperature. This will basically keep your water warmer than the thermostat is set at, so the heater element won't come on.

Powering the pump with a solar panel is also a good idea, since otherwise you'd radiate the geyser heat out at night.

Edit 2 : Look what popped up on one of the sites I visit regularly : http://hackedgadgets.com/2008/02/07/diy-solar-refrigerator-water-heater/

[JJCOOL]

What you really need to know...

There are currently many different SWH products available on the market, and customers need to well informed prior to deciding which unit to purchase. At face value many solar water heaters appear to be similar in design, but in fact there is huge discrepencies in the performance of these products.

The main considerations are:


Sizing of the unit - how many users per day?
Performance - more efficient units will achieve higher temperatures thereby increasing your amount of usable hot water
Positioning - all solar units should be positioned in a true north direction and at the correct inclination angle for your location
Pressure - high pressure units will retain your existing water pressure (but are more expensive), low pressure systems are cheaper but you will only get a fraction of the water pressure you have previuosly enjoyed
Materials of construction - the unit will be located outdoors 24/7. So it makes sense to buy a product which will not corrode or rust over time and must be well insulated to prevent unwanted heat loss
Efficiency - is the system optimised to take advantage of the suns energy, even under advers conditions.
Is the unit freeze and hail resistant.
What temperatures can be expected
What are the different installation options that are available
What is the installation cost
What is the payback period.


I would urge anyone who is considering going the SWH route to make sure they are getting EXACTLY what they need, with particular referce to the above issues.

As far as DIY setups go, these are unlikely to provide water at anything more than 45 degrees.

I sell an internationally patented SWH system that can actually boil 264 Litres of water with only 6 hours of sunshine.

Anyone who would like more information is welcome to contact me. My advice as to the "in's and out's" of various systems that are available is free.

[kilos]

JJCOOL I see the SWH you use is pretty popular making news in the
TIME magazine http://www.microsolarsystem.com/art.htm

Local company in George selling SWH from China
using vacuum tubes www.green-power.co.za

Would be great if a magazine like Popular Mechanics SA
can do a test with all the different SWH manufacturers.
to see which one is the best value for money.

[BCO]

Those Mikro SWHs look very nice indeed.

[JJCOOL]

Thanks Kilos.

Yep. Great system.

My demo units boil the water almost daily - of course we are not running these under load. But customers can expect to get 75 - 80 deg daily - which is already much higher than standard geysers.

Other evacuated tube systems are just copy-cat products and are actually infriging our our international patents.

The SABS has a R28 Million test rig from Germany which they use to rate systems and give certification - therefore Popular Mechanics SA probably would not have the funding. Mine is nearly complete with SABS testing after 5 months.

[JJCOOL]

Those Mikro SWHs look very nice indeed.

Thanks BlueCollar - you should see how well it performs, it is unlike anything else I have seen locally.

[BCO]

Thanks BlueCollar - you should see how well it performs, it is unlike anything else I have seen locally.

Bah, pity I spent R14k on a Solahart last year, coz I'd have been quite interested in one of yours (not that I'm at all unhappy with the Solahart).

[JJCOOL]

R 14k for solahart is cheap - Their 300L system is now R 30k, and mine is half that price.

[psc]

Other evacuated tube systems are just copy-cat products and are actually infriging our our international patents.


There are many evacuated tube designs (solar), most predating Malaysia's Teoh Siang Teik "Microsolar" (US Patent # 6,014,968) issued 2000.

1985, Billy Hunter of California (US Patent # 4,505,261).

In China, Qing Hua has been making evacuated tube solar panels since the 80's.

If I remember correctly "Sunlight" is one of the current major (Chinese) producers, one can buy the tubes independantly ideal for DIY.


Based on this I feel that your statement that they are copy - cat producers is somewhat bold, most use a different means of collecting the solar energy in the evacuated tube. :)

http://www.diytrade.com/china/4/products/2954187/Solar_Water_Heater_Solar_Collector_SFA_series.html

[JJCOOL]

There are many evacuated tube designs (solar), most predating Malaysia's Teoh Siang Teik "Microsolar" (US Patent # 6,014,968) issued 2000.

1985, Billy Hunter of California (US Patent # 4,505,261).

In China, Qing Hua has been making evacuated tube solar panels since the 80's.

If I remember correctly "Sunlight" is one of the current major (Chinese) producers, one can buy the tubes independantly ideal for DIY.


Based on this I feel that your statement that they are copy - cat producers is somewhat bold, most use a different means of collecting the solar energy in the evacuated tube. :)

Fair comment PSC. However there is an interesting back story.

It is true that the patent was awarded on the product itself in 2000. However, in the mid-eighties a chinese person (name unknown to us) actually went to visit Mr. Teoh Siang posing as a reporter, took some photographs and subsequently returned to china and reverse engineered the product. The patent was applied for and awarded some time later.

This story was related to us by Mr. Teoh Siang (the inventor) himself, when we were recently with him in Malaysia.

The patent does not apply specifically to the use of evacuated tube technology - however many of the design elements have been copied and are now readily available in South Africa as sub-standard products.

We have no intention currently of suing anyone for infringement of patent rights - but we find it necessary to point out to the general public that similar looking products WILL NOT deliver the same performance levels.

We are simply trying to educate the public into making informed choices.

[psc]

@JJCOOL

Fair Comment, I wish you the best success. One question, in the unlikely event a tube breaks is there a way of preventing water loss ?

[JJCOOL]

@JJCOOL

Fair Comment, I wish you the best success. One question, in the unlikely event a tube breaks is there a way of preventing water loss ?

It will depend on the way the tube breaks. The evacuated tubes can fracture on the outer layer (thereby releasing the vacuum) without the inner layer rupturing. No water will be lost with this kind of breakage, and the damaged tube can be indentified easily due to the fact that the barium getter located at the end of the tube will react with the oxygen in the air forming barium oxide - a white compound. This white compound coats the bottom end of the tube and makes spotting fractured tubes extremely simple.

If a tube shatters through an extremely large impact i.e a brick, then the tank will drain. Both Mikrosolar and our distributors keep stock on spare tubes and replacing a tube is a very simple operation.We have also developed a polypropylene "emergency plug" which can replace a tube until it can be replaced.

In all cases a broken/fractured tube will not seriously impact on the units performance.

[BCO]

R 14k for solahart is cheap - Their 300L system is now R 30k, and mine is half that price.

I have the 200l unit, and I was fortunately part of the initial rebate pilot project so I got R6k back, bringing the price to R14k.

[JJCOOL]

I have the 200l unit, and I was fortunately part of the initial rebate pilot project so I got R6k back, bringing the price to R14k.

Have you noticed a significant decrease in your electricity bill since installing this unit?

And do you always have sufficient hot water available?

How many hours a day is your timer controlled element operational?

[BobbyCash]

Hello,
What's the latest take on the SHW heaters from Mikro?
Thanks

[Mr Blah Blah]

Can anyone advise me: I have had a Microsolarsystems water heater installed (25 l) by a bit of a Laurel and Hardy outfit.

Following installation the hot water pressure was discernable lower.

I am wondering if it was installed correctly. The cold water main goes directly into the solar water heater and from there feeds into a pressure geyser.

Logically this sounds ok, but conceivably it could go FROM the pressure geyser TO the solar water geyser. Would this have any effect on the water pressure?

Has anyone else had problems with decreased hot water pressure linking a solar water heater to a pressure geyser??

[JJCOOL]

There are various installation configurations that are possible. What you are describing is a standard pre-feed/pre-heat type set up which is one of Eskom's approved methods.

The Microsolar tank itself contains a heat exchange coil made from approx 30 metres of 1/2" copper piping. If you take into account the additional pipe work required to connect the inlet and the outlet of the solar this could be an average of another 10m of pipework (much more in some cases).

This means that you now have an additional 40 - 50m of pipes in your sytem to your point of usage. It is normal to have a small pressure drop due to pressure/friction losses through your pipes - around about 15% pressure loss would still be normal. Anything above this should require further investigation.

On a normal 4 bar water supply a 15% pressure drop is negligible - but if your water pressure was poor before the solar was installed then you would more likely notice the difference.

Any solar water heater - regardless of make or model - will require the addition of extra lengths of pipework.

We could re-pipe your system so that your geyser feeds into the solar and then onto your taps - but from a pressure point of view this would not make any difference. If your consumption was erratic or very low, then the geyser first option would be feasible.

Please PM me if you are still experiencing difficulties and I will get our installer to contact you and rectify your problem.

[BigAl-sa]

Has anyone else had problems with decreased hot water pressure linking a solar water heater to a pressure geyser??Had mine for more than 10 years and the pressure is pretty good. There is a drop in pressure caused by the Masterflo valve, but you have that with a high pressure geyser anyway.

[Mr Blah Blah]

Thanks JJCOOL. That is useful. I reckon the pressure drop is proabbly about 15%- on erratic and low pressure to start with.

Is there any reason why sometimes the overflow spouts copious amounts of water - to the point where I have had to go up on the roof and adjust the valves? This has happened a few times...

[Deenem]

Solar Water Heater Exhibition on at Sandton City Fountain Court ATM.

If anyone is interested.

[JJCOOL]

Is there any reason why sometimes the overflow spouts copious amounts of water - to the point where I have had to go up on the roof and adjust the valves? This has happened a few times...

Hi Mr Blah Blah

The expansion of the water on heating is accomodated by making use of a vent which is open to the atmosphere - thereby preventing any potential pressure build-up and possible explosion.

If one takes into account the co-efficient of expansion of water, heating up from 20 degrees to 100 degrees celsius will result in an additional volume of up to 5 litres. The tank will drip more as the water temperature increases (much like the overflow on a standard geyser)

The auto fill valve automatically maintains the level in the tank by relpacing any water lost through venting (through the vent pipe or through the temperature safety valve). It is not recommended by us that the auto fill valve be adjusted by the client - the installer will set the valve during the installation.

If your system is venting more than 5 litres per day then perhaps a little tweaking is in order. Why not let one of our trained installers come out and just check that all is in order.

btw: Are you satisfied with your water temperature - and have you noticed a reduction in your electricity usage?

[GreenBean]

JJCOOL,
See your location is stated as Alberton. I'm based in Alberton and would like to find out more about your system and how it works in practice as everyone claims theirs is best. Let me know how we could go about it. Been to mikrosolar.co.za and have a pamphlet, so I'm familiar with the system itself. Please email me: jacques@greensource.co.za

[Hosehead]

Go to any home expo today and you'll be all but assaulted by Solar Greysers.

I also used one between which by now must now be 10-12 years old and I see all these new ones being touted as the best thing since sliced bread and wonder what's really changed besides the astronomical price tags. These things were a novelty back then...

Some of my recollections with this and specific to the Cape.

These things boil during summer. Literally. The overflow was a scalding torrent of water over the side of the house in the middle afternoon (during the hottest part of the day) It was also connected to the solar mat on the roof to heat the swimming pool. I could turn off my internal electric greyser during summer months (Blue Sky days) but during winter months- even with sunny days- I'd have to turn it back on because the solar was incapable of heating even a thimbleful of hot water - never mind the pool.
So May thru November were write off months for my Solar Greyser. The rest of the year I had more hot water than I knew what to do with.

Now with water and electricity tariffs what they are, I think any savings are negligable because these offset each other.

I was recently in the market to buy a solar unit for someone else but until the unit cost comes down or the subsidy is increased and the new technology is SABS approved to our climatic conditions (There's so much choice out there but which brands are tried and tested?)- it's just not worth the extra hassle and expense.

[kingmonty]

What do they cost nowadays? And is there still a subsidy?

[BCO]

As far as I know there is still a subsidy, albeit a fairly small one that varies depending on which SWH brand/type you buy.

It's been a while since I looked but prices, I think, range from like R5k to R30k.

[kaybeach007]

Hello boys and girls. SWH are becoming more and more popular and important to us. Eshkom, as with most government institutions, is a screw up. The important thing to realise is that electricity costs will double over the next 4 - 5 years. Yes 15% - 20% increases annually are on the cards, so buy the SWH now and save from day one.

On the Eshkom DSM website is a list of all approved (get your rebate) installers. The rebate is based on the type of system, it's efficiency and the amount of local content in the manufacturing process. All systems are SABS approved in order to qualify for the rebate. To get SABS approval they need to heat the water in a certain amount of time and retain that heat for a specified amount of time.

All the systems are much of a muchness. Flat-plate and vacuum tubes are the two technologies available. In Europe and Canada vacuum tubes are preferred but in Africa, with all our sun, it doesn't matter which you choose. Flat-plate is low tech, doesn't break, more than efficient enough to do the job (you don't need boiling water, 65C is what you want - don't get caught up with salesman speak). Calculate on 50 litres per person (200 litres for family of 4).

I have had one for years with no electrical backup and haven't had a cold shower yet, with 3 women ruling the house, guess who showers last (I have a beautiful wife and often need cold showers, but can't have them).

I hope this post helps. Yes, you got me! I install SWH in the Eastern Cape. I believe that we all have to do our bit for the environ, but if you're a cold heart, then let me assure you that electricity prices will double in 4 years (inside info) 15% - 20% compounded annually! Eshkom will also be introducing punitive sliding scale tariffs soon, so prices will increase exponentially as you spend. Most 200 litre systems are about R20K and will pay for themselves in 4 - 5 years.

Some additional info: houses with SWH already installed are fetching R30K - R35K more than without, so home buyers are starting to put a SWH on their list of things to look for. Estate agents are specifically mentioning energy saving features as selling points, so there's more to these bunny hugging initiatives than meets the eye.

If anyone has questions just ask.

[captainwifi]

[[Category:Sasecurity]]

The commercial solar heaters at R35000 are just to expensive. Take that solar heater and determine it's weight and then ask yourself what would the equivalent raw mass of steel actually cost? Certainly not R35000. With modern CNC machines anything can be manufactured today on a small scale. There is no way we are going to make it in this country if people are conned into paying R35000 for solar heating. http://www.rawsolar.com specific means of generating electricity seems to be the most cost effective. The design is standard there is nothing fancy about it and there various patents surrounding it that we can hack. I have read extremely wide on this topic and have a pretty good idea as to how to crack this energy problem, getting it all unto a wiki with pictures and everything will take time though. These are a few preliminary sketches.

=== Patents ===
back to [[EskomPower]]. There are a series of patents on creating steam to turn a turbine generating electricity. These links will be updated as time allows. We can hack the patents and deploy the technology.
* http://scratchpad.wikia.com/wiki/SolarCooker
* http://scratchpad.wikia.com/wiki/EskomPower
* http://scratchpad.wikia.com/wiki/ElectricCar


=== $17 solar cooker ===
* http://blog.wired.com/wiredscience/2008/07/mit-students-cr.html ''$17 solar cooker using bamboo''
* http://www.oneearthdesigns.org
* http://www.rawsolar.com
* http://groups.yahoo.com/phrase/steam-turbines
* http://www.ausra.com/technology ''Compact Linear Fresnel Reflector, or CLFR, is Ausra’s solar power technology.''

=== Steam turbine and solar cooker design ===
Build a $17 parabolic reflector and focus the beams on a 3000cc casing boiling the water creating steam. The steam turns a turbine. The only constraint it seems to the creation of this energy is the cost of steel. By using bamboo for the parabolic reflector huge cost savings are enacted. We need to manufacture the turbine blades ourselves by purchasing our own CNC cutting machine. I will upload the specific patent that shows how to build a vacuum black body on which sun energy is focused as time permits. The idea was patented in 2000 thus it will only expire in 2020. We will use a http://scratchpad.wikia.com/wiki/FrontingCompany to manufacture these key patented technologies - this is an issue of life and death for us. You can't run 15kw motors on a farm to pump water of sun energy but if the city dwellers were to heat their water and recharge their battery operated white leds with this solar technology then you can remove yourself completely from the energy grid and only power your fridges and computers with Eskom power, leaving critical power for food production, mining and industry. Every time you power that geyser or switch on the stove you are burning hard $us currency and making your small contribution to destroying South Africa, it is time for a radical rethinking of how we will use technology maliciously patented.


=== others ===
* http://www.sunfire.co.za/solarcookers.htm
* http://www.sustainableprojects.co.za/?gclid=CI-UlIPl25gCFQxHQwodthULdg
* http://www.green4cent.com/HomeMadeEnergy.aspx
* http://www.microcare.co.za/solar_products.html

=== Focusing arrays ===
http://fuelzilla.com/groups/homepower/Solar-Dish-Collects-Concentrates-Solar-Energy-By-Factor-of-13601-.htm

http://www.naturalnews.com/024631.html

http://www.iedu.com/DeSoto/Projects/Stirling/Heat.html


=== Mastes thesis on solar electric steam ===
http://www.redrok.com/led3xassm.htm#newton

=== solar turbines ===
* http://www.green-trust.org/wordpress/2005/07/23/diy-bladeless-disc-steam-turbine/
* http://www.green-trust.org/steamturbine/steamturbine.htm
* http://www.green-trust.org/steamturbine/Solar_White%20Paper_Part%201.pdf
* http://fuelzilla.com/groups/homepower/Solar-Dish-Steam-Turbine-Electric-Generator-2144-.htm
* http://www.quasiturbine.com/ETypeSteam.htm
* http://www.neon-john.com


=== search terms ===
Use these search terms at http://www.patentstorm.us.

removable brackets, concentrator, reflector, parabolic, electrical energy, solar radiation, anode , charge evacuated receiver, photovoltaic , incident light , fresnel mirror, fresnel lens solar fluid heater, solar collector, system and method for concentrating sunlight ,

SYSTEM AND METHOD FOR CREATING A NETWORKED INFRASTRUCTURE DISTRIBUTION PLATFORM OF FIXED HYBRID SOLAR WIND ENERGY GENERATING DEVICES

collimating backlight , Apparatuses and methods for shaping reflective surfaces of optical concentrators

Heat actuated cooling system , optical concentrators , perimeter monitoring techniques

[ToxicBunny]

wify : Have you ever tried any of your "theories" yourself?

[Arthur]

Question:

On a double story house, does the solar 'collector' panel for a decent SWH system have to be on the top roof, ie above the geyser, or can it be at any height? The reason I ask is that, for aesthetic and serviceability reasons, I'd prefer to have the panel(s) on a north-facing stoep roof rather than on the roof above the top floor.

[syntax]

What do they cost nowadays? And is there still a subsidy?

You will pay between 9 - 30k for the system. There is a subsidy if you use certain types of geysers, and its aroudn 2 - 2.5k.

And yes, this is a mild punt at my signature.

[captainwifi]

[[Category:Sasecurity]]

=== solar turbines ===
http://www.green-trust.org/wordpress/2005/07/23/diy-bladeless-disc-steam-turbine/
http://www.green-trust.org/steamturbine/steamturbine.htm
http://www.green-trust.org/steamturbine/Solar_White%20Paper_Part%201.pdf
http://fuelzilla.com/groups/homepower/Solar-Dish-Steam-Turbine-Electric-Generator-2144-.htm
http://www.quasiturbine.com/ETypeSteam.htm
http://www.neon-john.com


From this site http://www.green-trust.org we get

http://www.greensteamengine.com/licenses.htm Connect this steam engine to a solar heating system you can build yourself as described in Pop mechanics 2008 to generate the steam from the sun. The steam engine turns a generator for electricity.

The design is covered by patent http://www.patentstorm.us/patents/6647813/fulltext.html.

[ToxicBunny]

have u tried this yourself wify?

[elmorya]

"SWH are becoming more and more popular and important to us. Eshkom, as with most government institutions, is a screw up. "

I think this is the point we are all missing. Eskom have screwed up big time and now want the consumers to pay/sort themselves out. Now from reading the above forums - people seem to falling for it -they are buying all these overpriced "solar gimmicks", which by their own admissions do not work was well as they hoped. Works well in the summer months only is the general consensus. I think we need to confront Eskom as a united front (together with all the Unions), resident associations, and whatever other bodies that do exist in our society. Touting figures like R30 - R40k as "affordable alternatives" only serves to send a message to the bureaucrats as " Ha they have money!" Let's hit them with another hike/increase/etc! Next thing you will be paving your own roads and disposing your own sewerage!

"Let them eat Cake"

[BCO]

I don't think they're gimmicks or that they don't work as well as hoped - at least not with my SWH.

Also, not sure where you got your figure of R30k - R40k.

[syntax]

they are buying all these overpriced "solar gimmicks", which by their own admissions do not work was well as they hoped. Works well in the summer months only is the general consensus. . Touting figures like R30 - R40k as "affordable alternatives" only serves to send a message to the bureaucrats as " Ha they have money!"

What are u talking about?

Overpriced gimmicks? maybe ur looking at rubbish units then? I can name a few in the 9-15k price range which work really well. I have switched off my geyser completely for just under a month now with water that is almost boiling? As in NO ELECTRICITY going to my geyser and still getting over 60 degree water out easily...... Surely that means its working?

Only works well in summer months? Most panels work equally well in winter and summer, and at sometimes better in winter due to less cloud cover.

30-40k alternatives? Are u thumb sucking ur facts and figures here?

[DigitalSoldier]

You will pay between 9 - 30k for the system. There is a subsidy if you use certain types of geysers, and its aroudn 2 - 2.5k.

And yes, this is a mild punt at my signature.

Think I saw solarharvest on the eskom approved supplier list :D

http://www.eskomdsm.co.za/?q=Solar_water_heating_Background_information


With immediate effect consumer rebates will now be paid directly to consumers and not to the installing supplier. In order to claim the rebate for the system fitted by approved Eskom suppliers, the purchaser will submit a claim for the rebate to Eskom's auditors who are facilitating and monitoring the process.

The rebate system is not in anyway exclusive. The requirements of a supplier to sell systems that qualify for rebates are the following:

* Be able to offer a 5 year guarantee
* Submit documents, including public liability and company details
* Have system tested AND passed at the SABS for the following;
o Safety
o Mechanical
o Thermal

The choice of what systems are submitted for testing is solely up to the supplier.

Important: No rebates are paid for systems which were installed before your system, your supplier or your installer were registered on the programme.

[syntax]

Probably, however you wont believe how hard it is to get some of the tendersetc.... Its pretty tough to try do things legally and still get ahead. It is not actually my company, but i did design the electronics for it and it would be nice to see it succeed. Will see how it goes....

[ecokid]

I agree that Eskom has let us down
I just saw a company on Cape Town gumtree offering a pressure heater for R5500 150L

lets hope prices are all going to come down
http://capetown.gumtree.co.za/c-Business-Services-other-150L-High-Pressure-Solar-geyser-only-R5500-W0QQAdIdZ112600643

[2CentsWorth]

I got 10 quotes and all of them quoted me R15k - R25k (after rebate) for the installation of a SWC. My geyser popped, and I figured well let's just replace with a SWC. However:

1. the insurance wasn't willing to cover the replacement to HWC
2. excess on replacement geyser (electric): R1000.

My total monthly electricity expenditure is R520 (I reckon R180 of that is thanks to the Geyser). If I had to install a HWC, it would take me more than 75 months before I start seeing a genuine saving (probably more if you take interest into account)

If they really want people to seriously consider these things, then they will need to bring the overall costs down to something comparable to electricity driven cylinders. And at least get the householders insurance to cover it when an existing geyser does burst.

[syntax]

I got 10 quotes and all of them quoted me R15k - R25k (after rebate) for the installation of a SWC. My geyser popped, and I figured well let's just replace with a SWC. However:

My total monthly electricity expenditure is R520 (I reckon R180 of that is thanks to the Geyser). If I had to install a HWC, it would take me more than 75 months before I start seeing a genuine saving (probably more if you take interest into account)


As i said, the prices vary quite a bit, but trust me there are panels that will cost around 9k with installation after rebate.

The savings depends on how you use ur electricity? On our place, our electricity bill was almost halved. Our geyser has not been switched on in over a month and a half (this includes the rain days etc...). We are saving around R225 a month on electricity, means you have paid for the system in under 5 years.....(and during power failures we run certain "critical lights" off the system which is pretty cool....)

electricity is only going to get more expensive....I agree its not cheap right off, but its getting better

[captainwifi]

http://scratchpad.wikia.com/wiki/Solar_Energy


=== Stirling Engines ===
http://www.stirlingengines.com Sun catcher Stirling engine design as described in popular mechanics 2008 December.
* http://www.patentstorm.us ''Patent: 7134279''
Use a 3-D laser scanner to scan every screw, nut, bolt and curve on the Stirling engine into Autocad then publish the design somewhere on the internet.

Hacking the patent is the moral thing to do.

[ToxicBunny]

My original question to you wify still stands.

Have you tried ANY of this stuff on your own home?

[duderoo]

Was just quoted R27000 from solahart.......what a outlay.

[BCO]

Was just quoted R27000 from solahart.......what a outlay.

Very good quality SWHs tho.

[Paulr]

Very good quality SWHs tho.

So it may be, but most people don't have that kind of cash to give out.

If, however, you integrate that cost with the cost of a new house/townhouse (those little 2 bedroom places that go for over a million!), it becomes a fairly small amount in the bigger scheme of things.

Which is why we need some people with guts in the government... Pass a law that every new dwelling (over a certain value) must have a suitable SWH installed as standard, and at least we can reduce the future energy demands in that regard.

Ah well, we can all dream can't we? :rolleyes:

[BCO]

So it may be, but most people don't have that kind of cash to give out.

If, however, you integrate that cost with the cost of a new house/townhouse (those little 2 bedroom places that go for over a million!), it becomes a fairly small amount in the bigger scheme of things.

Which is why we need some people with guts in the government... Pass a law that every new dwelling (over a certain value) must have a suitable SWH installed as standard, and at least we can reduce the future energy demands in that regard.

Ah well, we can all dream can't we? :rolleyes:

Agreed.

[voxhound]

If anyone is still watching this thread, Eskom has announced much improved (more than doubled) rebates. You can get the details here http://www.eskomdsm.co.za/. The rebate for the system I just installed went from R3,800 to R8,200. Bad timing for me.

[Paulr]

I just did a search on Eskom's site for suppliers in Gauteng, for a 200l pumped indirect system.

Even after the new rebate, the average price still comes to around R20k including installation! :cry:

Sorry, but I (and most of the people I know) don't have that kind of cash. Even by financing it, there would still be an impact on my monthly cash flow for a few years, as the savings in electricity won't cover the repayments...

I'd also like to see what's going to happen to the prices of these systems in the next few weeks after the new rebates are announced....

[voxhound]

Paulr,

Looking at the data it is true that most of the best value options are not in Gauteng. I have no idea why. If you are happy to look at 200l pumped direct frost resistant systems, you can get:

SunAfrica SUN 200 total cost R6,441, rebate (measures performance) = R6,292.
Intisolar SFSHP 200 total cost R7,878, rebate R6,422.

If your daily hot water consumption justifies a 200 litre tank, I am pretty sure your savings would pay the extra monthly payment from putting R6-8k on your bond. R8k at 8.5% over 10 years costs R99 per month. I reckon you'd save that with two people showering even before the next Eskom increase.

For more analysis of the systems, take a look at my blog http://resourcemouse.blogspot.com

[Paulr]

Interesting, thanks.

R8k is a much better practical proposition!

One question, the prices you have in your post (total cost), I take it that is after the rebate?

[voxhound]

I have worked with price = system price + install price - rebate.

For many systems the system and installation give a range, I have used the lower figure for the calculations.

I have also used rebate as a measure of effectiveness, since that is what Eskom asked SABS to measure to calculate the rebates. For example if you have two systems that cost R8k after rebate, you should still take the one with the biggest rebate, since it works best.

When I get some time I plan to put together a spreadsheet with a few inputs and calculate how long it takes to get payback for a given system.

[Paulr]

When I get some time I plan to put together a spreadsheet with a few inputs and calculate how long it takes to get payback for a given system.

There's quite a few people on here who would be really interested in that.

What are you doing between 3 and 5 tomorrow morning!? :D :whistle:

[Moederloos]

It costs between 8 and 15 kw of electricity to heat a cold geyser to hot (200l).
The difference is due to ambient water tempreture (water going into the geyser is colder in winter than summer, so takes longer to get hot)

Kwh of power now costs +- 85c depending on where you are.
so, in the region of R10 to heat a geyser. If I switch my geyser off when hot and only back on when the water is cold, it lasts about a day for 6 of us.

So, a geyser will use around R300 a month for my household at current prices.
Going forward, in three years I can expect to pay:
R750 per month for hot water...

A 200l solar system will set me back around R20K (rebate excluded).
20K over 36 months is R555 (excluding interest).

And I show Eskom the middle finger - worth R500 a month, easily.

[pietb]

Just something to take note of:

The information on the Eskom supplier list is somewhat outdated even if the list was updated with the new rebate figures.

As someone mentioned, the system with the higher rebate is a more effective one. SABS allocate a "Q" factor to each system. The more effective the system the higher the "Q" factor the better the rebate.

[kaybeach007]

Greeting Everyone

I install solar geysers, Kwikot to be exact. Good solid brand, 20 year life span if you service the tank and change anodes every 2 - 3 years.

Costing 150 litre system:
150L Kwikot Solar Tank = R4 600
Conergy Collector Panel = R4 000
Roof bracket/stand = R1 000
Pressure control valve = R500
4 x 5.5m class 1 copper pipe = R1 280
Connex Vacuum Breakers, connex elbows & tees = R450
Solder elbows & tees = R120
Labour = R1 500
Subtotal = R13 450
VAT = R1 885
Total = R15 335
Gross Profit = R1 565 (haven't paid my diesel, phone, rent, bank loan, etc yet.)
Cost to client = R12 200, ROI < 36 months.

Any significant truss reinforcement would be added to price. Put a 350kg point load on your roof and see what happens in 6 months time, I've had some good laughs at bad jobs.

Most people forget about all the extras, sure the system costs you R8 600 ex vat, but the rest adds up quickly. I'll put R3 000 worth of copper piping in you roof and you won't see it, the above costing is absolute minimum. I can put class 0 copper piping in and all the old school plumbers will faint in horror in unison.

Profit on 200 and 250 litre units is a bit better, but not much. You have to do at least 40 - 50 installations per month to get ahead convincingly. Bakkies and vans need maintenance, employees need bonuses, landlords need rent, blah, blah, etc.

A word of advice. Pumped systems are not the best things in the world. Sit down with the installer and get him to find you a solution that does not require pumps, controllers or any other gadgetry. A well installed thermosyphon system will work without any gizmos, pumps or controllers and you don't need to sacrifice a lamb or even a chicken to get it to work.

My system runs on the sun throughout winter (no clouds in winter), I use electrical backup in summer (thick cloud and it rains), a good installer will design and position you system for winter, summer is not a concern, ask questions, tell the installer to show you where the sun tracks in winter compared to summer and ask him how the installation will maximise winter radiation exposure. If he cannot answer - chase him away. Some of my guys can't read or write, but I have taught them about the sun in winter and summer, where it is and how to maximise exposure, how to deal with dorma windows, flat roofs, A-frame houses, trusses and spreading loads, reinforcing trusses as well as what happens to a baby when 200 litres of 65 degree water bursts and floods it in its cot - it's happened!!!

It's an interesting time for the industry and lots of debate, which is good. Lots of fly by night installers, but they will be weeded out over time.

DO YOUR HOMEWORK, ASK QUESTIONS.

[Paulr]

A word of advice. Pumped systems are not the best things in the world. Sit down with the installer and get him to find you a solution that does not require pumps, controllers or any other gadgetry. A well installed thermosyphon system will work without any gizmos, pumps or controllers and you don't need to sacrifice a lamb or even a chicken to get it to work.

If you install a solar powered pump (extra costs, I know) you won't suffer during blackouts etc. Otherwise, why do you say that?

[voxhound]

I have a system I installed 12 years ago (2 x flat panel + thermosiphon = no pumps needed), and it works well. +/- 100% of heating needs the sunny half year, +/- 50% of heating needs in the colder half year. I am in the Cape where summers are sunny but winters are often cloudy. I recently installed a system for my mom, and used a pumped one because it had a good SABS/Eskom rebate rating. It does seem very efficient, but it will not work when the power is off for the pump, and there is more to go wrong.

I am still working on the spreadsheet for savings and payback.

[Nerfherder]

I have an idea for a geyser conversion, can anyone tell me if this will work well ?

I have heard that you can change your geyser element from a single element to a dual element, the theory is that two smaller elements will pull less power. In a normal situation where you have a full hot geyser only one element will power up and maintain the heat. When you have an empty geyser fulling up with cold water then both elements will kick in.

What I want to do is link the primary element up to a solar panel, it would not need too much power. Then hook the second element up to the normal mains.

In the morning you shower and the geyser empties. Both elements heat up and half your power comes from the sun and half from normal power. Then during the day the heat will be maintained by the primary element (Solar) and if there is not enough sun the other element(mains) will kick in. Obviously you can further improve the system by using insulation and even by putting a timer on the mains part of the system.

This would be cheaper as it does not require a large solar panel as you would to power a larger singular element. It should not require any specialized additions (I'm no expert though) and could potentially be fitted to any normal geyser.

We already know that you can leave your geyser off during the day, provided you adjust the temp etc. Some of us are forced to do this anyway.

So do any of the geyser installers think this is a good idea ? How much would it cost ?

[kaybeach007]

Hi Paulr
Most pumped installations use a small 12V pump to circulate the water. They run off a 10W or 15W PV panel. There is usually a controller of some kind that manages the pump. All this does is add to the mix of "THINGS THAT CAN GO WRONG". We often have problems with the pumps and controllers and have to go back and replace. You want a system that needs the minimum amount of maintenance. If you are rolling in it, no problem, phone me and I will maintain/replace at the drop of a hat for a price. For the average Joe, thermosyphon system, no hassle, no fuss, change the anodes every 3 years (20 minutes) and the system will give you 20 years of free hot water.

Nerfherder
The smallest VIABLE element for a 150L geyser is 2kW (average SA domestic size). Assuming that you have a Kwikot geyser, machining costs for a new cover plate approx R2 500. 2 x 1kW elements approx R500. So the conversion of the tank is R3 000 (the cheap part). Now let's look at generating power. If you power one 1kW element with PV you need (assuming 100% efficiency) 5 x 200W panels at approx R8 000ea = R40 000. 5 x mounting bracket sets = R1 000. Cabling R2 500 (you have to use large cross sections for DC) = R43 000 in total.

150L Kwikot Solar geyser, fully installed R16 000 - R17 000 less rebate R4 700 = R12 300. I'd go for the solar geyser.

[voxhound]

Folks, I have done my "business case" spreadsheet for a household to calculate the payback time for a solar panel. It is still a bit rough, but you can use or download it at my bloghttp://resourcemouse.blogspot.com.

I think the basics are pretty sound, but please feel free to suggest corrections or ideas for improvement.

Note also that Eskom say the rebate will be reviewed (reduced) after a year. My advice: strike while the iron is hot.

[kaybeach007]

Excellent Voxhound.

Some general advice. For families that mostly shower, we always recommend low flow showerheads. We use 6L/min showerheads, fantastic! At 6L/min you are using 4-5L/min hot and 1-2L/min cold, so a 150L geyser gives you 30 - 37 minutes of shower time.

We often try and convince people to start reducing their consumption and install smaller systems, it's good for the environment and good for their pocket. Why install a 200L or 250L system when you can get by on a smaller 150L system?

I measured a showerhead the other day at 25L/min. The family wanted 2 x 250L systems installed (R26 000 x 2 = R52 000 (nice business for me) less R7 900 x 2 = R36 200 total) for a family of 4 (mom, dad & 2 teenage boys), all of which showered and I said no way, impossible! I talked them into installing a 200L system and 2 low flow showerheads for them (R23 000 - R7 200 = R15 800). Saved them a whack in installation costs, a whack in ongoing electricity costs, reduced their water bill, each one has a 10 minute shower now AND they reckon the new showerhead are better than the old big drain cover they had.

It's a nice feeling when you get to help a family save R20 000 with something as simple as that. Remember, going solar is more than just saving electricity and money, it's about saving our planet as well (although I must say getting a cheque from Escum for a couple of grand and giving them the finger is the cherry on the top)!

Remember, saving the planet one geyser at a time!!!

[Wynsam]

Folks, I have done my "business case" spreadsheet for a household to calculate the payback time for a solar panel. It is still a bit rough, but you can use or download it at my bloghttp://resourcemouse.blogspot.com.

I think the basics are pretty sound, but please feel free to suggest corrections or ideas for improvement.

Note also that Eskom say the rebate will be reviewed (reduced) after a year. My advice: strike while the iron is hot.

Thanks for the work you did here. I am finding it most useful.

[rph72]

The suppliers list doesn't seem to work. :(

http://www.eskomdsm.co.za/?q=swh_supplierslist

Will send them an email. Looking for suppliers in Cape Town, Northern area.

[voxhound]

rph72 I have just checked and the Eskom suppliers list is working now.

[voxhound]

Two new developments:

- The City of Cape Town says it plans to set up a system to fund solar hot water installations with a monthly repayment on your rates bill (offset by your electricity savings).
- Santam have announced a scheme to replace burst conventional geysers with solar systems in insurance claims.

Details and links in my blog resourcemouse.blogspot.com (http://resourcemouse.blogspot.com)

[rph72]

rph72 I have just checked and the Eskom suppliers list is working now.

Thanks. Initially it didn't work in FF, so I used IE. Seems to work in FF now. :)

[DeadCore]

i just imported solar panels for %75 of my house's power,i also use a solar geyser,the pipes are laid over the roof between my solar panels.works well but it costs a lot,it's worth it.

[bender442]

Don't know if anyone is still monitoring this post, but here's my 2c:

I got my solar geyser a few months ago and I don't know why more people aren't doing this. My water temp today was 65 degrees (Cape Town) without any electrical backup.

I've calculated my payback will be less than 3 years. I'm on prepaid and have already seen my bill dropping - will have to do a proper analysis to work out how much, but it is really noticeable.

There's a lot of info in this thread about pricing but really you must just do your homework. I looked at about 10 different suppliers before I made a decision. Price was not my only criteria but it was a big factor. In total it cost me R15968 for a 300L high pressure system after the eskom subsidy. And that was including installation and everything.

I paid R28450 for system + installation, got R12482 back from Eskom. The thing was installed in a day, and I had hot water the same evening. So far so good!

Bottom line is if you want to save money, you have to spend money.

-- E

[Pieter @ 4 Seasons Solar]

Hi bender, Yeah that system you got is the one with the highest indirect rebate at the moment, we sell them up here in the Transvaal and we have had nothing but praises, We had a family the other day that said, theirs was at 78'C, then they had a shower and it went down to 64'C, the following morning it was at 63'C......... "Bottom line is if you want to save money, you have to spend money." , I agree with this, you can go and buy a R10k system from china, and buy another one 3 years from now, and another one 6 years from now or you can spend R30k now and have a system with a life expectancy of 15+ years, made by people that has been making solar geysers for 48 years.

[kaybeach007]

Hi there all.
I always enjoy it when solar guys brag about how hot their systems get. Utter rubbish. Remember anything over 65'C is a waste as well as reduces the life of the geyser, especially the PEX and composite lined tanks. Ceramic lined tanks can take higher temps for longer, but still deteriorate fast if heated too much. Remember galvanic action and thermal stress increases with temperature, so chase the saleman out the door if he brags that his system reaches anything more than 65'C.
Oh and by the way, SANS 10106 section 5.4.5. specifically states "Where the temperature of the stored water is not set to 60'C, the system shall be fitted with a mixing valve.". What that means is that ALL SOLAR GEYSERS must be fitted with a mixing/tempering valve because you cannot control the upper temp on a solar geyser, especially not EVT systems. A mixing/tempering valve is a valve that mixes cold water with the hot water, so that the water is never more than 60'C when it comes out of the hot water tap. It is a safety feature and is required BY LAW, so check that your installer is putting one in. They cost R500 - R750, so the guys love to "forget" them and make make a few bob more. If you do one installation per day, that's an extra R10 000 - R15 000 profit per month. That extra profit is nothing when a child opens the hot water tap by accident and gets 2nd degree burns to their face and upper body.
Please guys, hot water is dangerous.

[BigAl-sa]

Hi there all.
I always enjoy it when solar guys brag about how hot their systems get. Utter rubbish. Remember anything over 65'C is a waste as well as reduces the life of the geyser, especially the PEX and composite lined tanks. Ceramic lined tanks can take higher temps for longer, but still deteriorate fast if heated too much. Remember galvanic action and thermal stress increases with temperature, so chase the saleman out the door if he brags that his system reaches anything more than 65'C.
Oh and by the way, SANS 10106 section 5.4.5. specifically states "Where the temperature of the stored water is not set to 60'C, the system shall be fitted with a mixing valve.". What that means is that ALL SOLAR GEYSERS must be fitted with a mixing/tempering valve because you cannot control the upper temp on a solar geyser, especially not EVT systems. A mixing/tempering valve is a valve that mixes cold water with the hot water, so that the water is never more than 60'C when it comes out of the hot water tap. It is a safety feature and is required BY LAW, so check that your installer is putting one in. They cost R500 - R750, so the guys love to "forget" them and make make a few bob more. If you do one installation per day, that's an extra R10 000 - R15 000 profit per month. That extra profit is nothing when a child opens the hot water tap by accident and gets 2nd degree burns to their face and upper body.
Please guys, hot water is dangerous.

My previous geyser (direct) lasted 15 years and was still working when the panel popped. On sunny days it used to get pretty close to boiling point. Most geysers have a sacrificial anode in them anyway, and that will corrode before the geyser does.

With my new geyser (indirect), I specifically asked that the tempering valve *not* be included as I use the hot water for sterilisation. The installer had no problem with this.

WRT high temperatures, the hotter the water, the longer it will remain usable under bad weather conditions.

[kaybeach007]

Hi BigAl

I hate to be the bearer of bad news, but what your installer did was illegal and the PIRB as well as IOPSA will pull his registration if they find out. Him and you don't have a choice, if a solar geyser goes in it must have a tempering valve, it's the law. The laws are there to protect the consumer. I understand that you use the water for a specific purpose, I have done work for dairy farmers and their requirement in the milk shed is that "they want it as hot as possible". In their case I put big signs above their 32mm valves, saying "industrial hot water, not for human consumption" to cover my backside. If you have a tap inside the house connected to that solar geyser and you decide to sell your house, you will be required to put a tempering valve on the geyser. The new owner will require a geyser COC as well as an electrical COC in the near future. The rules are changing and lots of people will get caught out.

WRT higher temps, the higher the temp the shorter the lifespan of the tank. Not many geysers have sacrificial anodes in them anymore, people want cheap and nasty, not quality. There are only a hand full of manufacturers that still do ceramic lined, anodically protected tanks.

[Paulr]

Hi there all.
Oh and by the way, SANS 10106 section 5.4.5. specifically states "Where the temperature of the stored water is not set to 60'C, the system shall be fitted with a mixing valve.". What that means is that ALL SOLAR GEYSERS must be fitted with a mixing/tempering valve because you cannot control the upper temp on a solar geyser, especially not EVT systems. A mixing/tempering valve is a valve that mixes cold water with the hot water, so that the water is never more than 60'C when it comes out of the hot water tap. It is a safety feature and is required BY LAW, so check that your installer is putting one in. They cost R500 - R750, so the guys love to "forget" them and make make a few bob more. If you do one installation per day, that's an extra R10 000 - R15 000 profit per month. That extra profit is nothing when a child opens the hot water tap by accident and gets 2nd degree burns to their face and upper body.
Please guys, hot water is dangerous.

Bit of a late reply, but anyways....

kaybeach007 - where would the mixing valve typically be fitted? I see on google that it looks like a typical adjustable regulator with 3 pipe connections and an adjustment screw. Is that correct?

I want to double check my system to make sure it's fitted.... :erm:

[kaybeach007]

Hi Paul
We use the Apex valve mostly, they are the most robust. They have 3 ports, hot in and cold in on either side and hot out at the bottom and a black plastic cover on top with a big adjusting screw underneath the cap. You would usually install it close to the geyser, because you have a cold water supply close by and you can cover the whole house with one valve. If your tank is outside (close coupled) then it usually is behind the tank where the pipes penetrate the roof, on a split installation inside the roof.
If you cannot find it call the installer back to install one, don't pay him for it either, it's a standard item on any solar installation and if he is Eskom accredited, he knows it.

[Paulr]

Thanks, I'll check.

[Pieter @ 4 Seasons Solar]

Yeah, too hot is not too "hot" , Unless you have a robust enough geyser too handle it, BUT, as said, it is law to get the water down to below 60'C. So if a salesman try the "but ours get really hot, to 90'C+" pitch, they are trying to compensate for something (quality maybe) . Most solar water heaters will easily reach those temperatures under the right conditions, but who will use 90'C water ?? I tell you what , go boil the kettle , and the stick your hand in it........, You would say I'm crazy right.... well why would you want your solar geyser to boil the water then?

Anyways, when shopping for a solar geyser, look at the quality of the system and I suppose the rebate is a fair indication of the quality.

[Pieter @ 4 Seasons Solar]

Hi BigAl

I hate to be the bearer of bad news, but what your installer did was illegal and the PIRB as well as IOPSA will pull his registration if they find out. Him and you don't have a choice, if a solar geyser goes in it must have a tempering valve, it's the law. The laws are there to protect the consumer. I understand that you use the water for a specific purpose, I have done work for dairy farmers and their requirement in the milk shed is that "they want it as hot as possible". In their case I put big signs above their 32mm valves, saying "industrial hot water, not for human consumption" to cover my backside. If you have a tap inside the house connected to that solar geyser and you decide to sell your house, you will be required to put a tempering valve on the geyser. The new owner will require a geyser COC as well as an electrical COC in the near future. The rules are changing and lots of people will get caught out.

WRT higher temps, the higher the temp the shorter the lifespan of the tank. Not many geysers have sacrificial anodes in them anymore, people want cheap and nasty, not quality. There are only a hand full of manufacturers that still do ceramic lined, anodically protected tanks.

Yoh Yoh, thats dangerous and like KB said illegal. We cannot stress how important the "bell's and whistle's" are on Solar Water Heaters......Sure!!! you might not need electric windows in your car, but you need to have a sacrificial anode....... you might not need an aircon in the car, but you need a mixing valve..... you might not need alloy wheels, but yo need propper insulation on the pipes...... My point is, the extra's on a solar system is there for a reason, not to make it more luxurious like the extra's on a car.

But that mixing valve thing is a big no no...

[Stokstert]

Regulations, regulations......I can adjust my electrical only geyser to 70ºC which is legal and no one complains, but I may not use my 70ºC solar heated water. WTF
The default setting on the mixer valve is normally 55ºC and most installers leave it at that. For kitchen use that is really on the low side and people should ask installers to adjust it to 60ºC.

[kaybeach007]

I know, regulations can be a bit tiresome, but they are there with the best intentions at heart, to keep us all safe. On a standard geyser, a plumber with half a brain will adjust the thermostat up to 70C if there is a long run length to the taps (over 15m), if it is a small house and everything is within 7 or 8m of the geyser, he adjusts it down to 55C. Never go below 55C, legionella bacteria flourishes between 45C and 50C. 55C is more than adequate for kitchen use, see how long you can keep your hands in 55C water, time it and tell us, good luck.

Bear in mind the fact that water under pressure in a solar geysers can reach temperatures of more than 100C, now boil your kettle and put your hand inside, see how long you can keep your hands in 100C water, time it and tell us, good luck. The point is to err on the side of safety, rather than rushing a 3 year old to the emergency room with 2nd degree burns on their face and hands.

Despite how clever we all think we are, regulations are born out of experience, trial and error and 2nd degree burns.

[Stokstert]

I am not washing my hands in the kitchen but utensils which are much easier to disinfect with 60+°C than 55-°C. Stupid suggestion to ask me to put my hands into a boiling kettle, it's the same as to ask me to drive my Porsche into a wall at 250 Km/h just because it can.
With that argument of yours, all cars should be governed to 55 Km/h just because most cars these days have a N-cap rating at which most people could survive such a crash. ;):D:whistle: