Solar Power Thread

Not to rub it in or anything, but it's at times like this that I'm glad to have made the investment in adequate power that's independent of the national bulk generator.

If grid power is restored as scheduled at 16h30, I'll post a screenie of the summation graph showing the inverter resyncing with the grid.
 
Arthur said:
Not to rub it in or anything, but it's at times like this that I'm glad to have made the investment in adequate power that's independent of the national bulk generator.

If grid power is restored as scheduled at 16h30, I'll post a screenie of the summation graph showing the inverter resyncing with the grid.
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How long have you had load shedding today?
 
piranha786 said:
Should the size of the solar panel, battery , inverter match?

Reason for my question... I want to experiment with solar energy, firstly for lightning(loadshedding), and maybe charging a laptop, phone, etc.

Say I buy a 651 car battery (always use it for my car again) with a 60w solar panel
4 x 5w led bulbs
400w inverter (I already have this)
Will a setup like this work?

The other option is to buy a ready set up kit for +- R1800
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Don't use a standard battery. You want a deep cycle battery. Discharging a standard battery will kill it quick
 
Currently looking at what the best location would be for solar panels. I know its best to have it facing north.

My house is 25degrees off north. I have a very steep roof with the pitch at between 45 and 50 degrees.

Looking at my house now at 18:15, the front north facing side has no sun, the side west facing is in full sun and will be until 19:00.

What would an ideal pitch be for the panels?

I am putting up a carport that is sloping 5degrees to the right and could put the panel on top of the carport.

How far apart can panels be spread and still be part of the same string?

I'm also planning on putting in some dormer windows to make use of the attic space so panel space on the roof is limited. Carport will be going up on the right of the pic over the driveway. The trees over the driveway will be removed before the carport goes up.
 

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Chimney is going to be an issue, as shading panels partially is a no-no. I wouldn't put any panels in its shade.
Partially shaded panels cause problems - eg they can burn/ fail.

Looks like you'll get about 14 panels up there (visually based on door size).
If its 14 panels, I'd just do one string.

If you can do more on top of a carport, stick another string on that.

Only going to get you 4KW though peak with 14 panels (about 10-25KW winter -> summer).

Whats your daily load look like?
 
oober said:
What I like about them is that they have a warehouse in Durban so at least you do not have to worry about the shipping part from overseas. They are very competitive in S.A avg. pricing here seems to be R11.97/W!

But as I said I'm still trying to figure out what sort of extra expenses there might be.
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Please post back if you do. Would also be interesting if their products are SABS approved.
 
HvRooyen said:
Signates:
Perhaps this website can help?
http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php?map=africa
I ran a few simulations for my house (also facing slightly east of north) and it seems a 50 degree tilt may be ideal for me - better balance between winter and summer generation.
Comment from someone more knowledgeable will be appreciated.
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Thanks.

Using the default settings for losses and only editing location, inclination and azimuth, it looks like an 8kw pv system would be what I need.

5kw solar panels (20 x 250w panels)
2 x 5kw MPPT grid tied inverters (http://www.thepowerstore.co.za/ProductInfo.aspx?productID=MKS6150-48)
Getting two inverters for now and will add the rest of the panels later.

Other reason for going with this inverter is that it allows for both grid and generator inputs and will allow me to add batteries later on. If there are other inverters at a similar price point and deos the same and is locally available, I might consider them. For now it these seem to be the best.

PV Calculation.jpg
 
Before you spend, have you checked whats using your power?
Have you gone through and looked at what the major loads are, and ways to reduce those first?

30-35kw can probably be brought down quite a bit, especially if most of that is hot water or cooking related.
 
Already converted my geyser to a heat pump and cooking with gas as well.

I have a pool pump running 6 hours a day and a pond pump running 12 hours. Not exactly sure how much electricity my six strand, 150m electric fence consumes. All lights are already CFLs and floodlights are LEDs.
 
So I have given this a lot of thought and also found the information in this thread extremely helpful in making up my mind. I am still using a regular stove and Geyser and our usage is approx. 15-25 KW a day, with the extremes mostly the geyser during winter. I am assuming then if I replace my Geyser with a heat pump, usage, it will always be below 20KW a day regardless of the season. What would be the proper Inverter capacity, and panel configuration be for me to start off with. My double garage has a flat roof, while the house has a steeped corrugated roof.

I would like to do this in stages (due to costs and my reluctance to make debt), so batteries etc. would be the last stage.

Also If anybody knows of a good company I can approach for this in the cape town area, I would really appreciate it.
 
Electric fence is in the double figures of watts.
 
HBee said:
So I have given this a lot of thought and also found the information in this thread extremely helpful in making up my mind. I am still using a regular stove and Geyser and our usage is approx. 15-25 KW a day, with the extremes mostly the geyser during winter. I am assuming then if I replace my Geyser with a heat pump, usage, it will always be below 20KW a day regardless of the season. What would be the proper Inverter capacity, and panel configuration be for me to start off with. My double garage has a flat roof, while the house has a steeped corrugated roof.

I would like to do this in stages (due to costs and my reluctance to make debt), so batteries etc. would be the last stage.

Also If anybody knows of a good company I can approach for this in the cape town area, I would really appreciate it.
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If you get a heat pump just make sure you can still use the internal element of the geyser I'd the heat pump does not work.

I have a heat pump and when the water was disconnected due to maintenance being done, the heat pump did not work as there was a high pressure error. Had no hot water for a week until the technicians came out to fix it.

With a solar geyser you do not have this problem as when there is no sun, you can just use the geyser as normal.
 
I'm bringing in another few pallets of panels (40 panels per pallet), shipping est late Jan, arriving start of March (shipping everything prior to Chinese New Year). Landed price should be about R2700-R2900 a panel (including tax/vat invoice) for a 300W panel
(pricing subject to clearance charges, and the rand not going too far above R11.5, but should be in that ballpark).

Spec's: 300W 36V (8.63A) / Size 1936*992*50mm / Cotech Panels.
PDF's etc can be supplied on request.


I still have shipping space in the container, so can also share shipping if any of you want to share space (currently about 5-10CBM spare). Shipping will be from Shenzhen -> Cape Town.

PM me if any interest, and for more details.
 
Sheesh Lsheed_cn, you in the market selling panels now!

Certainly could be interested. When do you need to know by?
 
lsheed_cn said:
I'm bringing in another few pallets of panels (40 panels per pallet), shipping est late Jan, arriving start of March (shipping everything prior to Chinese New Year). Landed price should be about R2700-R2900 a panel (including tax/vat invoice) for a 300W panel
(pricing subject to clearance charges, and the rand not going too far above R11.5, but should be in that ballpark).

Spec's: 300W 36V (8.63A) / Size 1936*992*50mm / Cotech Panels.
PDF's etc can be supplied on request.


I still have shipping space in the container, so can also share shipping if any of you want to share space (currently about 5-10CBM spare). Shipping will be from Shenzhen -> Cape Town.

PM me if any interest, and for more details.
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Are these Poly or Mono panels ?
 
A slight derail. I had some solar chaps over here on Monday, and I was a bit aghast at the prices they were quoting. What got me reconsidering, at the end of the day, was the price of the batteries. Said batteries which could not be guaranteed for any real lifespan. I have a prepaid meter, so cannot feed back into the grid.

So either I go for a UPS solution, or an off-grid scenario. The cost (as quoted to me) for a UPS solution makes no sense for 4 hours of backup. Off-grid would be nice, except for the damned batteries again. R130k, with half of it basically being the batteries. Which need to be replaced at intervals of (hopefully) 7 years or longer. Whatever calculations I do, I do not see a saving over electricity.

Which leads me to my question - with my situation, how would solar be better than a 20k-30k standby diesel generator hooked up to mainboard?
 
Splinter said:
Which leads me to my question - with my situation, how would solar be better than a 20k-30k standby diesel generator hooked up to mainboard?
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For starters, the cost of generating electricity with a generator is at between R4-R5 per kWh. So the longer you are on a generator the more expensive it will be. For backup power, a couple of hours a week, it should be ok. I bought a 5kw generator this week just for standby generation if the grid is down and there is no sun.

The cost of batteries was also my problem as I was not prepared to put up that much cash into the batteries.

I have an old school meter so technically I can feed back, this is still illegal but approval can be given but there is a lot of red tape to get this approval.

Going to be getting a 5kw solar system hooked up hopefully in the next few months that will back feed during the day as there is no one at home to use what is generated during the day. At night I will use what I exported during the day. Will double the capacity in a year to 10kw and begin adding batteries in a few years time if prices come down.

What size solar system did they quote you on for R130k?
 
signates said:
For starters, the cost of generating electricity with a generator is at between R4-R5 per kWh. So the longer you are on a generator the more expensive it will be. For backup power, a couple of hours a week, it should be ok. I bought a 5kw generator this week just for standby generation if the grid is down and there is no sun.

The cost of batteries was also my problem as I was not prepared to put up that much cash into the batteries.

I have an old school meter so technically I can feed back, this is still illegal but approval can be given but there is a lot of red tape to get this approval.

Going to be getting a 5kw solar system hooked up hopefully in the next few months that will back feed during the day as there is no one at home to use what is generated during the day. At night I will use what I exported during the day. Will double the capacity in a year to 10kw and begin adding batteries in a few years time if prices come down.

What size solar system did they quote you on for R130k?
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They didn't quote specifics - which is why I am a bit wary of them. The "quote" for a UPS system was also full of gaps and inconsistencies. And this is supposedly a "connection" price - as in brother-in-law of a friend. But regardless, I did look at quite a few pages in this thread and the prices seem consistent with what has been posted.

But yes, ultimately it boils down to the fact that I cannot feed back into the system. So a proper diesel generator will cover all my needs given current circumstances. And quite frankly, if the grid goes down for longer than I am able to buy diesel, I reckon this entire country is fooked anyway. Being off-grid will most probably only make you a target for the "zombies".
 
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