DIY geyser conversion to solar

jls_n said:
R9085

The fittings and the pipes was around R500+
Click to expand...

Sounds interesting

Jenny Crwys-Williams just had her place done and more or less said that the cost of that was around R18000 (I think before the R4000 rebate).

My brother had a system installed to heat water for his pool. I'll ask him what that cost and what temperatures he is getting in winter - slight difference between a pool and a shower, or washing dishes I know.
 
Hey

here is some news regarding my installation.

So far it's been going great with the geyser. Temp on some days is around 55 - 57 degrees. Ive seen a few days above 60 degrees.

The only time the geyser uses electricity is between 3:30 and 5:00 when it heats up for me to shower to go to work. Been on leave for a week and a half now and no need for electricity except when the wife wants to wash the towels. thats normally once a week. My monthly bill has dropped with about R100. What i can also say is this. my bill for last year was not under 1700 - 1800 a month. Due to a koi pond that i builded and the pump running 24hrs a day.

We spoke to the town council for kempton and they told us we should go onto the b - tarif rate. Since the change over to the b tarif rate and installing the solar tubes the account avg on 1200 - 1300.

Other Problems:

One day due to load shedding the temp inside the manifold where the tubes connects to got so hot it melted the vacuum breaker causing the water to leak out. The reason is the pump needs electricity to circulate the water.

I tested the control panel to see how much amps the pump uses and it seems it uses 0.1 amps or around 22 watt. small rectifier with a car battery will do the job.

Thats the only big problem i had so far.

Over the weekend when the temp dropped so low the geyser registered 45 - 48 on the panel.

For rainy days i'm not sure about will make a note when it rains again to take temp readings.

BoB

Ive uploaded pictures to the site to show the connections.
http://mybroadband.co.za/photos/showgallery.php?cat=596&ppuser=42335

if u still have queries please pm me.
 
how much is the eskom subsidy? How much will you pay in total + installation out of your pocket then??
 
I know this is an old thread, just wondering if you can give any updates on your installation. How has it worked out over time?
 
mmm that sounds like a lot of money, I am sure one can convert a normal geyser and supplement it with hot water for under R6k, that includes building your own solar collector. You just have to shop around for the right equipment. I'll be trying this soon on a new flat that I am building on my property.

Jls_n don't you have a problem with hail in the Kempton Area...it can hit those tubes flinters?
 
tau1z said:
Ok, why not just get a full system done properly for that price?
I saw another thread here for ecoboys or you can try http://www.solarharvest.co.za
I designed the electronics for them but dont get anything further so dont blast me for doing "advertising"...
Click to expand...

If you don't mind me asking, what kind of electronics? Differential temperature monitoring perhaps?

The reason I'm asking is there seems to be a number of "dumb" systems out there. With some sensors and software they can become a lot more "intelligent" and, obviously, efficient.
 
Paulr said:
If you don't mind me asking, what kind of electronics? Differential temperature monitoring perhaps?

The reason I'm asking is there seems to be a number of "dumb" systems out there. With some sensors and software they can become a lot more "intelligent" and, obviously, efficient.
Click to expand...

It uses a plc to do a variety of things, like temperature and pump control, anti freeze systems, holiday modes, timers etc...
 
These solar systems have a payback less than 2 years now. I've just had a system delivered from a company called Cleanheat (they supply Cashbuild).

R5700 incl VAT for:

Wilo pump - 3 speed settings.
Black Frame (no 90 degree mounting brackets, no assembley instructions)
15 tubes, 54mmOD x 1.8m. I've seen similar online at R80 to replace.
Relay/PLC box (same as JLS_N's), with instructions
Display panel (same as JLS_N's), with instructions
3x temperature sensors, with long leads
2x stainless steel thermowells (fittings to screw temperature sensors into)
Delivery was free to JHB, in a series of cardboard boxes.

Additional parts required:
4x s/s angle brackets, 4xs/s bolts and nuts, 5m copper tubing, various unions, 90 degree bends (10 odd) 2 x brass valves, 2x T's, insulation and tape, solder, gas solder gun. Important: an electrical contactor (heavy duty relay switch) is required for big or old (2kW+) geysers like mine, as you risk melting your PLC. Total extras (DIY from scratch): R1100 approx.

I will try to fit this to one of my two geysers. I have an old, "square" low pressure geyser, supplied by a water tank. This will mean solving problems, like:
* locating the frame low enough to remain charged from the tank (i.e. very cramped access, so I'll have to strip tiles to get in there)
* Positioning the circulating pump low enough to get enough suction head on the pump.

Currently, I have nil plumbing experience and limited electrical experience, so it should be fun. I will post pictures once I have things up and running.

The other solar project that I have started, is to build a photo-voltaic array to a standard capable of lasting 25+ years. I have now purchased 2kW worth of individual cells. Quite a long payback, but what the hell. DIY is cheaper than commercial, but not many people feel confident in exceeding commercial quality, or have the time to research or the hands-on affinity.
 
Solar Geyser installation completed

Hi,

I have finished installing my solar geyser. See it here:

http://mybroadband.co.za/photos/showphoto.php/photo/14015/title/solar-geyser/cat/500

My insulation efforts are quite effective, losing only 1ºC overnight.

It has been running for nearly a month now, and I have only had my geyser on for 4 hours (total) for supplimentary heating. A fully programmable system, whichever way you look at it.

Hot days, (like now in summer) the 200 litre geyser reaches 64ºC
Cloudy days, it barely makes 36ºC
Average: I'm guessing 55C. Not bad for a 15 tube panel on a 200 litre geyser. Note that the geyser supplies 2 showers a day. If I needed more, I'd have to go 18 tube.

The Minimum temp for a shower = 44ºC
Minimum temp before having to turn on cold water = 50ºC

I'm a bit dissapointed with some of the additional components that I wasted money on, like galvanised fittings from Cashbuild. These are RUBBISH!!! I broke (cracked) several while hand-tightening and only spotted this once comissioning, when I got leaks. If I had not fitted a drip tray, I would have had to try make an interesting/creative insurance claim. Utter rubbish galv components. Go to a reputable plumbing shop for galv fittings. Conex fittings from Cashbuild are fine.

I had to use metres and metres of copper tubing, as my geyser is on South end of roof, and the solar panel and pump are on the North end. Copper tubing is very expensive. If you are on a budget, strongly consider going galv tubing and a manual threading machine.

Zip-lock pipe insulation is very effective, but expensive unless you hunt around (R40 a 2m length). A buddy I know used an old magazine collection and duct tape for his insulation - wrapping the magazines around the tubing.

As stated before: panel, pump, temp sensors, PLC, electronics box - R5700.
All-in, including the materials and all tools required works out as R8500 (18m more copper tubing than I planned - see above). This price excludes labour. A less complex system like a high pressure geyser (no stand pipes - less tubing) and I'd guess R7700 or less is possible.

I am not a plumber or electrician, but I managed to figure out all the skills and tools required from scratch and got it installed in 6 days, by myself over 3 weekends.

Lessons to remember:

1) install planks in your ceiling between trusses. You can always do the marathon yoga-solder sessions, but planks will keep you from cramping up and falling through the ceiling.
2) Conex fittings always seal, every time. Galvanised fittings do not.
3) ALWAYS have a means to drain the geyser. I had to wet-fit (literally hot-fit) a means to drain the geyser. Doh!
4) Always open a few tiles on the opposite side of the roof for ventilation. It gets extremely hot in a roof space.
5) Always have a continuous stream of cooling water flowing onto drill bits that are drilling through concrete tiles. They last much longer.

I'm not punting this company, but I used Cleanheat components (they are all chinese components, regardless which system you buy):
Kenneth Tam: [email protected]. I had a faulty temp sensor thermowell (leaked), which he replaced without quibble, or charge.

Regards,
Bob
 
Last edited:
Nice update, thanks. And well done on the installation - that looks like a serious job!

Your performance from a 15 tube system is not bad at all.

How is your PV project going?
 
DIY PV panel progress

Pretty slow on the PV side... I need to speed up if I want to get capital return on the R10k of new solar cells I've bought. In hindsight, buying them now was a bit premature, but at R5 a watt I think the price wasn't too bad at the time.

If cells are expected to work more than 5 years outdoors in all weather, then they need to be hermetically sealed. All the usual DIY systems you see on the internet with wooden frames, lexan plastic and no encapsulant are hopeless long term solutions, unless kept indoors.

Modern methods of cell incapsulation require mass production methods. Two sheets of specialised plastic are used, with heat and vacuum to create a laminate sandwich. While a cheaper method, it needs expensive machinery and can't be done DIY without a proper vacuum system.

Then, there is the "old school" method of making panels. It has stood the test of time and panels from the 1970's still work. However, is labour intensive and involves sealing the cells inside a silicone or other substrate.

I am trying to source high quality silicone pottant similar to Sylgard for the solar cells directly from China (this seems to be mega-expensive stuff). I also still need low-iron, non-reflective armoured glass (which no-one in SA seems to make). Etching the glass with Hydrofluoridic acid is extremely dangerous (and a dumb DIY move). The rest of the parts are off the shelf and fairly cheap: framing aluminium, sheet aluminium, backing plastic, tabbing wire, diodes, etc.

Then I need to solder the 500+ cells together in accurate jigs; pre-coat the cells with silicone pottant (painting the stuff on thinly, then letting dry). Then I plan to pour silicone on 1.5m^2 panes of glass (1mm layer), placing cells over the wet glass, letting that dry and then sealing on top of that with a final 2mm of potant. Plastic and aluminium backing, aluminium framing.

That way, no moisture whatsoever can affect cells over the next 25 years. The glass also becomes more forgiving when hammered by hail. Of course, if the glass breaks, so do your cells.

The PV system will be used to run fridge, freezer, pool pump, TV and lights. The stove, iron, kettle, dishwasher, washing machine and geysers will still be on the grid. I'll probably move to gas eventually for most of the cooking.

I'll be staging the PV installation so that I can tinker and shakedown panels by at first running the pool pump as a dedicated system off of the first few panels (no battery at first).

What a pity that the government does not force Eskum(plaine) to implement grid-tie electricity generation, where average joe public sells excess power back to the national grid.
 
PV Array info

R5 to R6.50 a Watt should be about what you are looking for if you buy PV cells in bulk, landed cost. We are talking about the raw solar-cell product here: undamaged, unmounted, untabbed, silicone wafer, monocrystalline, A-Grade, 3.95W solar cells. They are about 0.2mm thick x 165mm square(ish) - extremely delicate and must be kept extremely clean when handled. I got mine off e-Bay when the dollar exchange was pretty good.

The local (ZA) off-the-shelf rate for a complete PV panel is R30 to R60 a Watt for silicone Photovoltaic (about R64k for a 2kW array), or R200 a Watt for flexible (roll-up) photovoltaic panels (R400k for 2kW). Remember that I still need to spend a ton (another R10k) on materials to finish the array, making it about R10 a Watt once done, excluding my time (which would be I'm guessing another R15 a Watt). I choose to exclude my time input involved.

Warnings on DIY solar PV panels:-
* You cannot make high efficiency solar PV cells. You would need a sophisticated laboratory and considerable resources and deposition machinery to produce a decent PV cell. The only viable DIY method is to buy complete PV cells and make/assemble panels.
* Spend your money on worthwhile energy saving goals first. Probably most worthwhile in this order:
Geyser blankets (R100-R200)
Better ceiling insulation (R x)
Energy saving light bulbs (R34 each)
Energy monitor (Efergy, Owl, etc) (R300-R1000)
Better ventilation for fridges/freezers (R200 - R2k)
Solar Geyser (R9k-R16k)
Gas hob (R2k - R4k)
Skylights (R3k each)
New AAA+ fridge/freezer/dishwasher/washing machine. You may find fridges/freezers are borderline return on investment cases for energy saving purposes (18y+ ROI)
Solar Stirling generators systems (R100k per 2kW - a 2.5m dia. mirrored dish (2011).)
Solar Panels 2kW (R25kDIY-R100k. complete with ancillaries: R40kDIY-R400k)
Off the grid system 6-8kW: (R100k-R400k. " " " ": R160k - R1.0M)
Last time I looked, wind power was cheaper, but you need to go really high up - something like 20m for best results. This means you can't really build this in a built up area.
* Most PV cells for sale online (eBay) are B grade factory rejects. You really have to get a good deal from a reputable supplier - you have to gamble a bit. My cells checked out okay as A-Grade. Not even one broke in transit. Some need a clean.
* Don't bother with buying broken or chipped cells if you are building large panels. You are wasting your time trying to fix them. Important: using chipped cells will restrict the maximum current to the weakest cell in a series string. You will lose LOTS of power because of 1 bad component.
* Beware online "Solar eBooks". Unfortunately, 99% of these are scams, some providing stupid/obvious/basic infomation like "this is how to assemble it", then only showing a vague schematic and leaving it up to your imagination to complete. Do not buy an eBook unless you have reviewed a chapter and feel confident of its details, usefulness.
* Sattellite-grade efficiencies are 20%+ now. Commercial panels are 17-18% efficient. Rejects are 10%-16%.
* Implementing a production line with a project like this helps reduce time involved. Plan your time carefully.
* Important DIY tip: avoid tinkering and experimenting. Do your research properly. Find technical papers, adequate materials and suppliers upfront. Look at other peoples DIY efforts. Settle on a complete design. Buy materials for one small (tiny) panel, test it and settle on that method upfront for the production run. Measure materials accurately. Only order what you need.
* Many people say that building your own panel is at best a "science project" and not commercially viable. Somehow, DIY has become synonymous with poor quality. Few people are prepared to put in quality materials, time (huge time) and effort to produce a high standard. It is the aspect of time that makes self-manufacture a borderline venture.
* How do you value your time? Would you be sacrificing family time making panels, or just being more productive when you'd be doing nothing already. If you're rich, go ahead and buy your R100k system. Just leave poor me alone to build a more efficient system than yours.
* Batteries realistically only really last about 7 years before needing replacement. Factor this into the running cost.
*An argument is that commercial panels are "better" because they are "guaranteed" for 15 years. Big deal. How many chinese or start-up solar companies are going to be around in 15 years? Most panels are not guarenteed against physical breakage, which is the most likely mode of failure. I built an MP3 player 10 years ago. It still works, despite several component failures. My iPod Broke. It no longer works and can't be fixed. Go figure.
* "Average" middle class houses use (with some license) anything from 1000 -1300 kWh a month. A 2kW array will save only about 330kWh a month:
* Guesstimated electricity bill savings on a 2kW array (if you use most of the power productively) is about R200 a month at 0.59c a kWh. Assume Eskum increase prices 35% over 4 years, then down to 7%/y. A professional 2kW array is approx R80k all-in (inverter, panels, batteries, etc), so about 14 years return on investment (including 2 sets of battery replacements). DIY will be a R40k investment ttl, so about 8 year ROI, including 1 set of battery replacement.
* I may do a definitive instructible, as there are not many blow-by-blow solar panel instructions out there.

It turns out that solar panel manufacturers make a killing. Something between 40% on the low end and 60% profit on the high end if they source all their goods direct. But it is difficult building a good reputation in this business. Automation machinery is hellishly expensive, so is skilled labour.
 
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