Eskom energy costs have increased so it is viable go off-grid and get your capital costs back with return

AchmatK

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Not sure about daily, but I only use about 35Kw during the evening.
Are you sure?

35kwh at night would need a lot of batteries which is more than the R60k for your system.

Are you sure it's not 3.5kwh?
 

AchmatK

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My apologies, it is about 1.7kwh
That makes more sense.

We are 4 adults and 2 kids and need 10 times that just for our nighttime needs which comes to R100k just in batteries.
 

Tomasz-London

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Double the panels and maybe just maybe but I still wouldn’t risk cutting eskom.

This year Jan we had 5 or 6 days of cloud cover that my 5kw of panels couldn’t produce more than 7kw of power a day . It was unusual but in the last 3 years or so I’ve had my system , there has been more times like this . Granted both my geysers are on the solar system too. In summer I often have power I don’t know what to do with but it’s not a 365 day safe system (5kw panels , 15kwh batteries )

To cater for the odd bad days you would need to overspec the setup that 90% of the time would be Idle
Agreed, and subject to your spec, usage and discipline. However, my comparison was against their cost.
 

Gaz{M}

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Why bother going "off grid" at all, unless there is a huge grid connection charge you want to stop paying.

That way it doesn't matter if you have days where Solar and battery can't cover your load.
 

rh1

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Double the panels and maybe just maybe but I still wouldn’t risk cutting eskom.

This year Jan we had 5 or 6 days of cloud cover that my 5kw of panels couldn’t produce more than 7kw of power a day . It was unusual but in the last 3 years or so I’ve had my system , there has been more times like this . Granted both my geysers are on the solar system too. In summer I often have power I don’t know what to do with but it’s not a 365 day safe system (5kw panels , 15kwh batteries )

To cater for the odd bad days you would need to overspec the setup that 90% of the time would be Idle
Would a generator not be ideal for the overcast days (in addition to your setup)? I dont have a system yet. On my long "would like to have' list. So forgive if it sounds to simplistic.
 

Tomasz-London

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Why bother going "off grid" at all, unless there is a huge grid connection charge you want to stop paying.

That way it doesn't matter if you have days where Solar and battery can't cover your load.
Correct. During 80% of sunny days you over produce, feed back to grid, get kWh credits, and when needed, you pull from grid.
 

gimpex

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Would a generator not be ideal for the overcast days (in addition to your setup)? I dont have a system yet. On my long "would like to have' list. So forgive if it sounds to simplistic.
It is an option for sure. My particular inverter doesnt have a specific input for generator so I believe I would need to possibly "clean" the power coming from a generator into the inverter to make it look like its the grid.

Thought about it but haven't really investigated that option in great detail for now.

My concern with generators is the regular maintenance etc , so the few times a year you might need it , will it work. But I have never owned a generator , so these might just be horror stories which dont reflect reality.
 
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grok

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Compare how low electricity costs were under the NP, they were practically giving it away.

Now ask yourself about that ANC slogan of a better life for all. Are you even a Gupta or a Zuma? LOL!
 

rh1

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It is an option for sure. My particular inverter doesnt have a specific input for generator so I believe I would need to possibly "clean" the power coming from a generator into the inverter to make it look like its the grid.

Thought about it but haven't really investigated that option in great detail for now.

My concern with generators is the regular maintenance etc , so the few times a year you might need it , will it work. But I have never owned a generator , so these might just be horror stories which dont reflect reality.
Is it not just an engine, so normal maintenance and regularly running of the engine, should suffice, at least that how I see it. Another thing is also the brand, some are better than others and the type: on the job portable is being used as home stand by generators. Disclaimer: Not owned one, just been researching as a cheaper alternative to get some back up power in the interim, but also be able to be integrated into a solar/battery system later for the overcast days.
 

AchmatK

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Is it not just an engine, so normal maintenance and regularly running of the engine, should suffice, at least that how I see it. Another thing is also the brand, some are better than others and the type: on the job portable is being used as home stand by generators. Disclaimer: Not owned one, just been researching as a cheaper alternative to get some back up power in the interim, but also be able to be integrated into a solar/battery system later for the overcast days.
A generator on its own is fairly expensive to run.

Using it in solar battery system works out slightly better if you just use it to topup the batteries when needed.

Running a 5kw generator with a constant load just charging the batteries at 4kw for a couple of hours is cheaper per kwh than running it to supply fluctuating loads for hours directly where you will be drawing 1kw for a few hours with random spikes up to 5kw as the loads in the house changes. I would probably need to run it for 3 hours daily to keep my battery SOC up. The other issue is the noise as it would need to run at night/early morning as this is the time that the battery would run down.

I had a 5kw generator I think 5 years ago but it was a schlep to start it up everyone there was load shedding as I had the pull start one and not the key start. Ended up selling it after 2 years with maybe 30 hours of run time.
 

Crush

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I agree with the articles estimates. To go off-grid requires serious behavioral changes to your consumption and massive investment in batteries. I would even suggest that the 4.5kw of panels is waaaaay too small.

I've got 4.2kw of panels on my roof and for 6-8 months of the year I can cover 95% of my daily consumption. The problem comes at night... if you have guests over and need 2 more people to shower and have hot water. Or if you entertain on a Sat night. Or the wife wants to bake something and use the oven on a whim. Life happens and off-grid is hard to do. But reducing your bill by 80% is actually very easy I reckon.

My system cost me R140k... with extra labour and materials because my roof was not ideal for panel placement. I have 4.28kw of panels, a good 5kw inverter and 10.5kwh of battery storage. We have a geyser and a heat pump so water is heated primarily by the heat pump and geyser set to kick in to maintain a min temp if 2 or 3 people bath/shower at the same time. We also cook on gas so that saves a lot. Winter heating is by combination of very efficient aircons and gas, but we do use an electric heater in the bedroom for my little 3-year old. That alone kills an off-grid dream for my house in winter.

So it's really down to personal circumstances. If I go gas geyser, 2 more batteries and another 2kw of panels, I reckon I'd be almost entirely off-grid. But that's getting the cost up to around R230k total. And a few consecutive cloudy days will still ruin my plan.
 

rh1

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A generator on its own is fairly expensive to run.

Using it in solar battery system works out slightly better if you just use it to topup the batteries when needed.

Running a 5kw generator with a constant load just charging the batteries at 4kw for a couple of hours is cheaper per kwh than running it to supply fluctuating loads for hours directly where you will be drawing 1kw for a few hours with random spikes up to 5kw as the loads in the house changes. I would probably need to run it for 3 hours daily to keep my battery SOC up. The other issue is the noise as it would need to run at night/early morning as this is the time that the battery would run down.

I had a 5kw generator I think 5 years ago but it was a schlep to start it up everyone there was load shedding as I had the pull start one and not the key start. Ended up selling it after 2 years with maybe 30 hours of run time.
Hi AchmatK

Thanks, but should I get one, the long term plan is to use it as a redundancy to the solar system. But inputs like this is appreciated.

Another idea that I have, is that I am considering getting a smaller inverter/battery backup that I will use to power the lights, specifically the outdoor security lights. And, then getting a bigger invertor/battery back up for a select power points. And later getting solar. This way I can probably scale up as funds allow. Would this be feasible.
 

rh1

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I agree with the articles estimates. To go off-grid requires serious behavioral changes to your consumption and massive investment in batteries. I would even suggest that the 4.5kw of panels is waaaaay too small.

I've got 4.2kw of panels on my roof and for 6-8 months of the year I can cover 95% of my daily consumption. The problem comes at night... if you have guests over and need 2 more people to shower and have hot water. Or if you entertain on a Sat night. Or the wife wants to bake something and use the oven on a whim. Life happens and off-grid is hard to do. But reducing your bill by 80% is actually very easy I reckon.

My system cost me R140k... with extra labour and materials because my roof was not ideal for panel placement. I have 4.28kw of panels, a good 5kw inverter and 10.5kwh of battery storage. We have a geyser and a heat pump so water is heated primarily by the heat pump and geyser set to kick in to maintain a min temp if 2 or 3 people bath/shower at the same time. We also cook on gas so that saves a lot. Winter heating is by combination of very efficient aircons and gas, but we do use an electric heater in the bedroom for my little 3-year old. That alone kills an off-grid dream for my house in winter.

So it's really down to personal circumstances. If I go gas geyser, 2 more batteries and another 2kw of panels, I reckon I'd be almost entirely off-grid. But that's getting the cost up to around R230k total. And a few consecutive cloudy days will still ruin my plan.

I think that the idea is to have power for the key essentials and not be off grid 100%, for instance, if I could have power mainly in the morning and early evening that would be ideal as Eskom rarely load shed during the night.
 

Crush

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Absolutely.... I agree with that. My goal is also a cost and disruption one.

I'm happy to reduce monthly cost by 80% for 10 months and have 100% uptime all year around. And the large initial cost is actually funded from my homeloan so in my current case, I pay R1000 more on my homeloan but save on average R1200 on my monthly electric bill. So it's a win!

Edit: That was at the pre-June CoJ pricing, so I anticipate that the electricity savings are now R1350 per month.
 
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