Pony

I had/have one. I was trying to get it to turn a permanent magnet generator, but the wind was too erratic and it was not effective. I took the generator off, but the turbine is still spinning after about 3 years. 
 
Looks like this : 
 

I would recommend a good quality flat plate collector in a Thermosyphon configuration.
Characteristics that I would look for in the flat plate collector are as follows:
1) Copper risers & header manifolds
2) Copper or aluminum absorber 
3) Selective or semi selective coating applied to absorber
4) Preferably ultrasonic welding where the risers connect to the absorber
5) Iron free tempered glass or anti reflective coated glass as the cover
6) Strong extruded aluminum profiled casing
7) Mineral or glass wool as the back insulation.

Comments on Point 2:
 
If you install a separate DC earth electrode then that earth electrode must be bonded to the AC electrode. If you don't bond them together you could end up having a large potential difference between the two earthing systems under fault condition. (e.g lightning strike) This potential difference could lead to unsafe touch potentials.
 
To properly disperse a lightning strike you need a low impedance path to earth for it. So having multiple earth electrodes bonded together is a good idea to achieve that.

Hi everyone,
 
My solution to Eskom and the global warming issue goes like this; for hot water; a Geyserwise 900W/2200W AC/DC element powered through a Microcare 40A MPPT from 4, 305W black series Sunpower solar panels and then for electrics a 3kW plus Infini powered from 14, 305W black series solar panels with 8 100Ah Lead Crystal batteries as backup.
 
The system works great, the geyser has been up & running for just over a month and in this time I've only had to add AC power for half an hour on two occasions, otherwise we see 75 degrees almost every day.
 
The inverter is a peach. The Infini has been operational for 3 weeks now and has surprised me with it's output, and although the plan was not to run it grid-tied I tested it for a few days. The veld fire smoke here on the highveld really dampens the power generation, however I've still seen 21 to 24.4 kWh on normal sunny days and 13.1 kWh on a cloudy day.
 
Here are some pics
 











.

My two Axpert 5kva inverters arrived this morning, so next step is to start looking at batteries.
I'm on a bit of a budget so looking to get the best bang for buck.
 
My first question is which is better and why.
 
6v * 8 = 48v
or
12v * 4 = 48v
 
Not taking into account that you usually get more ah from the 6v batteries, which configuration is better?

2V x 24.  If one cell dies or get damaged for whatever reason, you only replace the single cell.  Only my opinion though.
 
If you look at pictures of all the big installations you will mostly see 2V cells and sometimes 4V or 6V batteries.  Capacity wise a 12V battery would also get quite bulky and heavy.  The other option is to connect multiple serial strings of 12V batteries in parallel to get the same AH rating.
 
Since you are going to use 2 x 5KVA inverters you are probably looking at at least a 2000AH battery bank - in that case I'll try to get very high AH 2V cells in order to have a single serial string instead of lower AH batteries in multiple serial strings connected in parallel.

Well well, all I can say is that I am extremely impressed so far.
Not any of my panels is truly facing north or at the correct angle, but it is not going too bad.
Here is what I got the past week.
I am extremely impressed with Yesterday, as it was overcast and rainy
 

Hi Wouter
 
May I ask what your interest in a VAWT is? I have built both vertical and horizontal, but vertical has been proved to be much less effective. They are OK as toys or as a reminder that lots of free energy is slipping us by every day. If you would like some photo's just let me know.
If you are at all serious about making some electricity, build a horizontal and at least a 1 kw.
 
Have fun,
windwize

Ok, so I spent another week-end on the roof contenplating which way to go with my panels.
Finally decided to go with 4 strings of 3 panels each.
 
Basically it came down to the Jinko and Tenesol panels not matching 100% in performance if I mix them in the same string
So now it will be 6xTenesol and 6xJinko. Could be a nice match-up.
Jinko to do the early morning sun to afternoon, Tenesol to do late morning to late evening.
 
So to make things legal and easier for me to measure and test, I installed a solar combiner + fuse box on the roof.
The cable is a 4 x 6mm trailing cable, so more than enough insulation and protection.
Each 6mm core should be good enough for 40Amp, so I'm covered there.
 

Well, as Grid-tied is not yet allowed in CPT, it is not really worthwhile going this route, just yet.
I got a normal 2nd hand invertor for very cheap from Gumtree, so why spend 3times that for something I was not sure I could use.
 
Once all the legalities is sorted in CPT, this will be my first option.
2nd would be Microcare.
3rd would be SMA (Sunny Boy)
 
For now only 3 invertors is certified by CPT, the MLT units, Microcare and Sunny Boy. I hope this will change soon

Ok, for now the contactors is sorted. Everything was mounted on some marine plywood.
The 2 main contactors is big, so if they switched, the smaller contactor would shake and loose contact.
Mounted the smaller contactor in a diffrent location, so that problem is sorted for now, I hope.
 
With my PV solar totalling 1880W (235W x 8) and my load over 2000W, I am getting some other problems now
As my battery bank is very small, only 200Ah and the load very big, I find now that my system keeps switching between Solar and Eskom around every 10min.
 
Options would be to schedule the motor run times better, but then I will get less time on the pool pump.
Increase battery bank capacity, but as I got the existing units free, I would not like to spend more money on the battries. Also only running load during the day.
Increase the PV capacity. As my roofspace is getting smaller, I might have to mount these new panels in a diffrent location.
Anybody know how this would affect the MPPT controller? I would hate to have to go and buy another one.
I was thinking of adding another 4 x 235W panels.
That would give me 3 strings of 4 panels each.
 
That would get me to 2820W total. At 48V the amps would be 58.8 which is still within the MPPT controller limit.
4 x 37V (Voc) = 148V. That is also still within the limit of the MPPT controller. Max is 150V.

Leaves, isolating circuits for when running on battries or mains is very easy.
The difficult part is getting the wiring for each circuit sorted out.
Just use a contactor with the coil powerd from mains. When the mains goes off, the contactor falls out and there is no power going to that circuit.
Once mains is restored, contactor will come back on and circuit will be live again.

Hi all,
 
This morning I came across a lightly used (6 month old, I'm told) set of Trojan T-125 batteries (4 of them), apparently thrown out of a golf cart not because there's much wrong with them, but because the owner of the golf cart converted to petrol after the controller board died. I was also given a warranty by the seller, so I can take them back.
 
What I'm trying to do now, is check the manufacture date. The interwebs says to look at the number stamped into the negative pole, but mine has none of those. It has several other numbers all over... someone had engraved A1027 on all of them, it has 0611 (or 1190, it's hard to make out what's up and what's down) melted into the case, and below the positive terminal it has what looks like U13C0AB. So at the moment my best guess is June 2011, which is hardly 6 month's old, but better than nothing.
 
Anyone know what to check for? So far 3 out of the 4 measures quite low, (SG somewhere in the 1100s, voltage around 6V, indicating a 50% charge level), so right now I have them hooked up to the solar panels to charge them up a bit... but it is somewhat of a cloudy day so this might take a while.
 
I also read a rant somewhere where someone claims these cells needs to be held at 14.8 (for a 12V bank, for me that would be 29.6V) to get a proper absorption charge. Anyone know if this is true, or whether 14.5V (or 29V for me) is sufficient?
 
Any other advice also welcome of course :-)

Geeze Mike, that sounds great!
 
Question:
How you planning to run the grid tied and bi-directional invertors together off a single solar array?
Why only gas for water heating? No solar heater?
 
As you right at the sea, make sure you do not have issues with metals. Solar panles does have an alu frame, so mounting them on a diffrent metal could cause corosion where they fixed

morning Wetkit,
 
backup mode with grid tied limiter:  for this method of connection the gti always feeds all power available from the solar panels to the grid. if  / when the grid fails then the gti will shutdown and the bi-directional will power the load from the batteries.
when the grid comes back on line the gti will feed power back again and the bi directional will draw some extra power from the grid to recharge the batteries.
 
Gas = no complications and zero power requ for elements. trying to do the total green thing :-) the gas geyser gives me 28l per minute at 55 deg. i dont need more than that.
All framing is Aluminium

Hi Sunboy.
Hope you well.
The best way to start would be to list your major components in your computer.
The name and model of each. With this we could sum up all the power requirements and get a good idea of how much power your machine uses.
Looking forward to hearing more.