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Real life Solar


Justipoohs
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I recently restored an old farmhouse in the Kalahari just outside Upington NC. I rebuild the house with solar power in mind, but was a little scared of the assumed cost. I must point out that  if I was going Solar I wanted to go 100% solar as just the standing charge on the Eskom pole is R850 per month.

Anyway, earlier this year I decide to take the plunge. The house is three bed, dining room, living room, kitchen, large stoep and a granny flat.

We also work from home full time.

We have a gas geyser for hot water and a gas range and oven to cook.

In the summer, and it's a hell of a summer in the Kalahari we use an evaporator cooler.

I did the calculations over and over again for daily kW used but still it only came to 3kw. So on that basis I installed 4x305w panels, a 3kw inverter and two 200ah gel batteries. Cost R28000

So we run a fridge freezer, a chest freezer, 2 x TV, microwave (just for re heat max 5min) lighting, washing machine 1xload per day, charge phones, laptops and the internet modem, pressure pump for the house water and evaporator.

We have not noticed the difference between Eskom and solar, the batteries seem to use 30% overnight.

My takeaway is that if you are prepared to look at alternatives to Electric stoves/ovens, and electric geysers and foresake aircon for evaporation then off grid solar need not be an expensive proposition.

 

 

Edited by Justipoohs
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9 hours ago, Scorp007 said:

Good that it turned out very well for you. With a 3kwh usage per day is not too costly. When you have to provide for 20kwh per day and allow for 3 days no sun and off grid then it is not cheap. 

That's my point surely "going solar" is the perfect moment to re evaluate usesge.

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2 hours ago, Justipoohs said:

That's my point surely "going solar" is the perfect moment to re evaluate usesge.

@Justipoohs embracing the offgrid lifestyle is a term I often use but I actually bought my aircons after installing my inverter and 6 panels and 4 lead acid batteries. On most sunny days 6 panels actually produces a lot of electricity as you can see on my screen shot. On cloudy days you won't need the aircon as much.Screenshot_20210727-104046_ShinePhone.thumb.jpg.c60638e361f304461acf0453ee054809.jpg

I was running a 18000btu aircon in summer on 6 panels and the wife was very happy.

What I'm trying to say is since you already have 4 panels another 4 might just be the trick to cool summers in the karoo. A 12000btu inverter aircon would probably peak at 1200watts.

The fine lines are the aircon going on and off, without the aircon my loads were also 400-600 which meant 6 panels was already overkill.

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20 hours ago, Justipoohs said:

I did the calculations over and over again for daily kW used but still it only came to 3kw. So on that basis I installed 4x305w panels, a 3kw inverter and two 200ah gel batteries. Cost R28000

That's very low. OK... you have gas for cooking and water heating. I'm guessing you don't have a pool (or at least a pool pump) and don't use a lot of convenience appliances such as a kettles and microwaves. What about a dishwasher? Still, it's a low figure and shows what you can get down to. And when you're down to a number like that then solar is cheap and easy.

I've used 7.67 kw/h so far today, but a good chunk of that will have been water heating. The pool pump doesn't run today. My "background noise" during the day ranges from 400 to nearly 700 kw/h. And I thought I was doing well.

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5 hours ago, Buyeye said:

@Justipoohs embracing the offgrid lifestyle is a term I often use but I actually bought my aircons after installing my inverter and 6 panels and 4 lead acid batteries. On most sunny days 6 panels actually produces a lot of electricity as you can see on my screen shot. On cloudy days you won't need the aircon as much.Screenshot_20210727-104046_ShinePhone.thumb.jpg.c60638e361f304461acf0453ee054809.jpg

I was running a 18000btu aircon in summer on 6 panels and the wife was very happy.

What I'm trying to say is since you already have 4 panels another 4 might just be the trick to cool summers in the karoo. A 12000btu inverter aircon would probably peak at 1200watts.

The fine lines are the aircon going on and off, without the aircon my loads were also 400-600 which meant 6 panels was already overkill.

The problem is here, outside Upington the cooling, in our case evaporator is needed more through the night in order to sleep so aircon isn't really an option without a 200k solar system.

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1 hour ago, Justipoohs said:

evaporator is needed more through the night

Care to give me/us some details on your evaporative cooler? What make? How large? What's the claimed/specced cooling capacity and what water are you using? (Kanaal water? would require some serious filtering etc.) and finally... What is the power consumption of this cooler? (and I suppose does it cool the whole house or only your bedroom?)

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1 hour ago, Kalahari Meerkat said:

Care to give me/us some details on your evaporative cooler? What make? How large? What's the claimed/specced cooling capacity and what water are you using? (Kanaal water? would require some serious filtering etc.) and finally... What is the power consumption of this cooler? (and I suppose does it cool the whole house or only your bedroom?)

It's a cool air venito, about five years old, kanaal water but from the treated tank so sediment settler already added ...rated at 200w on setting 3 but on setting 1 it does the job at 80w airflow is 4500 M2/hr and rated for Effective area 50m. It holds about 40 litres of water. Placed in the corridor it cools the whole house, if just in the lounge then it's very cool and back into the corridor for night time cooling ...only time it's useless nos if there's a thunder storm.

5 years ago it was R8000 from Midas, I see on Takealot now almost identical spec several brands for R4000

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17 hours ago, Justipoohs said:

cool air venito

Ok, a "Swamp cooler", humidifies the house and cools things down a bit... but hey, this last rainy season here in the valley, we had fairly high humidity at times and upcoming season I expect record rains for the Kalahari and Namibia/Botswana, whether that will comes to pass, we shall see, but if it does, the Swamp cooler will probably not do too much good at times, since the baseline humidity will be likely higher than normal by a healthy margin. Are you upriver or downriver from Upt and which side of the river? Here at onder Gariep with just shy of 5kW's worth of panels, we run the dishwasher during the day, cook with gas, but during the day will also run an induction cooker during daylight, at times etc. no batteries to speak of as yet and if no large-ish consumers are running, the load is also from 300W to 700W. Hot water is by way of evacuated glass tube hot water cylinder.

As for AC, don't have, might consider it in the future, but since we're here and surviving the climate since the end of 2008, we've sort of climatised and what the old farmers used to do, is drag the bed out to the porch at the end of November and leave it there until sometime in March next year... best air conditioning to be had, ok, Scorpions, Geel-slang etc. all something to keep in mind, but hey, you're closer to nature and not running up any sort of bill for air conditioning... 🙂

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We are south of Upt, 10km.before Keimoes.

Totally agree with you regards being close to nature ...As for rain I don't see the Kalahari ever having significant rain again, compared to when I arrived from the UK 10 years ago it's less and less every year.

I have found the evaporator to be far better for my health than aircon, and as you say only on thunderstorm nights is it next to useless.

What's the standing charge on your Eskom pole? Ours was R875 a month.

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21 hours ago, Justipoohs said:

Eskom pole?

funny thing, that, they cut us off last June & I scrambled to put in the solar end + an extension lead to the neighbour (150m worth of cable...)

We used to pay R 3k5 to R 4k a month, now, nada... actually still paying them off what I owe them at R 100.00 per month, maybe another 12 months and we should be square, since they want to stuff around, for the most part, I am supplying the neighbour a lot more than what we're consuming, only the last 3 weeks or so, has this turned around by us consuming, maybe from 0 to 5kW per day more than we're feeding back to the neighbour... that should turn around again latest by mid August, I'd imagine when the neighbour will get anything from 5 to 10kW fed from our end, more than we'd consume from his end.

Keimoes is on the western side, we're on the other side, closer to Grootdrink, half way, approximately between Groblershoop and Upington, so up-river from your perspective.

As for rain, let's see, if my thinking is correct, the rains come with the start of the solar cycle '09-10 was fairly wet, '10-11 was 500mm+ rain here and '11-12 also well above normal, normal here is supposed to be around 160 to 180mm for the rainy season. Last rainy season we had 270mm here, above normal and the beginning of the new solar cycle (you know, sunspots & better shortwave radio propagation, possibly...). 2 or 3 seasons ago, bottom of the solar cycle (mostly 0 sunspots) we had 38mm rain for the season! I do expect the upcoming rainy season to be better than the last, maybe not 500mm, but possibly approaching it, lets see, we're only here since end of '08, so I don't have enough historical data. A solar cycle is around 11 years times 2, every 11 years you get somewhat of a peak, the polarisation of the sunspots inverts, indicating the start of a new cycle, hence the 2 times 11 years app. since the 2nd time around the polarisation is back to the starting polarisation.

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