Solar panels on a whole house

MightyQuin

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#21
Hi,

If I no more want to pay electricity, is it possible to put the whole house into solar?

What are the best options to generate my own electricity for a 400 square meter house with 2 geysers and a pool pump plus outside lights?
Unlimited funds....
 

Cius

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#22
No gas. We have a wood-burning stove in the lounge, as well as a fairly well-insulated house. We are in Cape Town, so don't have the extreme temps of the inland cities. No aircon. We have electric blankets in the beds, so don't use electric heaters. Yes, your comment re the costs of solar vs our usage is valid. We had recently put in a new copper-lined geyser (which we still have), so it was the costs of the panel plus some plumbing and fitting. I'd need to analyse what we would have got had we invested that money, relative to what we have saved. But we took the conscious decision to do it for ecological reasons, not primarily to save money.
Out of curiousity how much did the solar geyser installation cost approximately. My electricity bill is steadily rising and I am thinking about starting down the road of energy efficiency with possibly the end goal of going off grid, but for now I will just focus on getting far more efficient.
 
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#23
Out of curiousity how much did the solar geyser installation cost approximately. My electricity bill is steadily rising and I am thinking about starting down the road of energy efficiency with possibly the end goal of going off grid, but for now I will just focus on getting far more efficient.
I have had a passive interest in this for years now. But enquiries in the UK from professional installers have led nowhere. SA is more potentially promising because of the sunshine, but what does concern me is how things would go maintenance wise. I go away for months at a time, and wonder if these systems need monitoring constantly.
 

Lupus

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#24
This might give you some sort of idea of likely savings. We had 5 years municipal records prior to our solar geyser installation in Dec 2009, and have kept track since then. Apart from visits from family (probably 3-4 weeks annually) and friends, and our trips (probably 3-5 weeks annually) our 2 person household has remained constant.
View attachment 561427
What was the cost of installing the solar geyser? As a 4kwh saving a day doesn't really seem to justify this, as I'm sitting at roughly the same usage as you and was looking at reducing it further as well. Trying to see if I could get it to under 9kwh a day.
 

Salmank

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#26
I found this article which is 3 years old:

mybroadband.co.za/news/energy/117579-how-much-it-will-cost-you-to-say-goodbye-eskom.html/amp

So now it should cost about half a million!
 

maumau

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#28
I got a quote last year from a company with an excellent reputation. R100k to generate a minimal amount of electricity. Enough to run a few lights, TV, fridge and pool pump.

What really, really put me off was a bank of batteries humming :(:( - even the fridge sound drives us crazy o_Oo_Oo_Oo_Oo_O

Engineer wanted to install them in a passage cupboard or under cover outside one of the bedrooms.

I was living alone at the time, spending less than R2k per month on electricity.
 

Lupus

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#29
I got a quote last year from a company with an excellent reputation. R100k to generate a minimal amount of electricity. Enough to run a few lights, TV, fridge and pool pump.

What really, really put me off was a bank of batteries humming :(:( - even the fridge sound drives us crazy o_Oo_Oo_Oo_Oo_O

Engineer wanted to install them in a passage cupboard or under cover outside one of the bedrooms.

I was living alone at the time, spending less than R2k per month on electricity.
With three people I don't even spend R1000 a month on electricity.
 

isie

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#30
I was living alone at the time, spending less than R2k per month on electricity.
:cautious: Are you mining or something, i spend under R800 (Prepaid i buy more then i use though so actual cost is less) a month 2 adults 2 kids
 

cbrunsdonza

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#31
What was the cost of installing the solar geyser? As a 4kwh saving a day doesn't really seem to justify this, as I'm sitting at roughly the same usage as you and was looking at reducing it further as well. Trying to see if I could get it to under 9kwh a day.
There is often zero ROI on going for a solar geyser, all you are doing is basically paying upfront instead of spreading it out over a couple of years. You still use electricity on a solar geyser, just a lot less and often only for short periods of the year (seasonal).

The only real monthly cost saving are for high usage users as you are taking usage off the top price tier. If you are already on the bottom price tiers then there will be insignificant savings.

You can consider doing the rent-to-own which is suppose to pay itself off, I did that but cannot say if it was worth it over buying upfront. Only advantage was I did not have to pay upfront.

The real benefit though is taking you off the reliance of electricity as you can still get warm water even in winter.

Also geysers do need to be replaced, so switching to solar when it is time is a good move. Consider doing a retro fit if your current geyser is still good - I should have done that.
 

Marsie27

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#32
Thought it would stay the same, or if it were me I'd use more knowing I'm not paying for electricity.

..... or is he not off grid and only talking about municipal usage.... ah, that must be it!
No, Maumau, we are not off grid, it's only our solar geyser that doesn't use municipal electricity, except for the pump that is incorporated in the panel system to circulate the water.
 

Marsie27

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#33
What was the cost of installing the solar geyser? As a 4kwh saving a day doesn't really seem to justify this, as I'm sitting at roughly the same usage as you and was looking at reducing it further as well. Trying to see if I could get it to under 9kwh a day.
Not relevant, as it was done in 2009, but back then it was around R12K, AFAIR.
 

SauRoNZA

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#34
There is often zero ROI on going for a solar geyser, all you are doing is basically paying upfront instead of spreading it out over a couple of years. You still use electricity on a solar geyser, just a lot less and often only for short periods of the year (seasonal).
Is your calculator broken?

The conversion kit for a retrofit setup to an existing geyser is 10k, even less on smaller geyser units.

If it saves you R500 a month (which it should do easily) then it's not even two years before the costs are covered and it starts paying for it's investment.
 

Marsie27

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#35
Some very rough calculations: If I were to invest R12K at 7% for 9 years (2009-end 2018) I should get around R7565 in interest. If we have saved an average of 4.916 kWh per day for 9 years, that equates to 16149 kWh saved over that period. We are currently paying R1.85 per kWh (I'd have to dig around to find what electricity cost in 2009 so just using that for convenience). So that equates to R29875ish, so if you deduct the R12K. I'd say we are still winning.
Anything wrong with my calculations or assumptions? We have to date had to spend zero on maintenance.
 
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SauRoNZA

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#36
Some very rough calculations: If I were to invest R12K at 7% for 9 years (2009-end 2018) I should get around R7565 in interest. If we have saved an average of 4.916 kWh per day for 9 years, that equates to 16149 kWh saved over that period. We are currently paying R1.85 per kWh (I'd have to dig around to find what electricity cost in 2009 so just using that for convenience). So that equates to R29875ish, so if you deduct the R12K. I'd say we are still winning.
Anything wrong with my calculations or assumptions? We have to date had to spend zero on maintenance.
Think you didn't compound interest.

Should be about R10,061 in interest.

One also has to consider that the price of that electricity will likely go up in future so you'll be winning either way.
 

Marsie27

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#37
Think you didn't compound interest.

Should be about R10,061 in interest.
I used the Nedbank online compound interest calculator for fixed deposits, with the interest added at the end of the term. I had to use 2, for 5 years and then 4 years. But sure, if I'd taken the time to "shop around" I guess I could make more with my hypothetical money:)
 

maumau

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#38
With three people I don't even spend R1000 a month on electricity.
No idea how you manage that. I was very careful with my usage.

:cautious: Are you mining or something, i spend under R800 (Prepaid i buy more then i use though so actual cost is less) a month 2 adults 2 kids
:) :) Not mining. Haven't got a clue how my electric was so expensive. We're now 5 people on the property and one of the other people feeds the meter, also on prepaid.
 

isie

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#39
No idea how you manage that. I was very careful with my usage.



:):) Not mining. Haven't got a clue how my electric was so expensive. We're now 5 people on the property and one of the other people feeds the meter, also on prepaid.
you need to do an electricity audit - figure out where and how you can cut down
 

Cius

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#40
We are 4 people, wife mostly cooks at home, and our winter bill is up to R1300 per month at R2 per KWH. Seriously think I need to get the complex to start looking at approving solar geyser solutions. If I could save roughly 1/3 of my usage it would pay off fairly quickly.
 
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