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Good day, Members.

We are renovating a house on a farm and are preparing to move there by the end of the year.

The Eskom connection is disconnected and we plan to stay off grid with a solar system.

I attended a 1 day solar system design and installation course hosted by Kragdag to gain some knowledge.

I have an electronic & computer engineering background.

But like with any new endeavour the magnitude of options have stumped me a bit.

Also, I almost fell prey to this scam: http://www.solarcityrsa.co.za/ image.png.bb82c24f1830c544168842724950ca9a.png

Which was reported here: https://www.reportacrime.co.za/CrimeReport.aspx?ID=33454

Luckily I didn't have the funds to immediately get it and I smelled a rat when their email address did not work and they don't have a physical address. When I  phoned the number on the site the guy ensured me everything is legit, but by then the red lights were flashing.

 

According to our current municipal bill we use between 19-34 kWh per day (summer - winter). Including geyser, heaters and swimming pool pump.

On the farm we'll have a solar geyser, no swimming pool and also rather use a fire place for heat in winter.

According to a online calculator we'll then be using about 18kWh per day.

I'll appreciate it if some of the knowledgeable members on here would answer some of my questions.

 

1. Does your wife use a hair drier?

2. Do you use a tumble drier?

3. Electric oven?

4. Laundry iron?

5. What is your typical kWh usage per day?

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Welcome,

To answer your questions,

Hairdryer ,  yes

Tumbledryer , no

Electric oven , nope

Laundry iron , yes

The iron is use mostly during the day when the sun shines so no use of the batteries , and the hair dryer is mainly use just as the sun starts to charge the batteries. Our house occupants consume about 12Kwh a day .

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1 hour ago, Vosser said:

1. Does your wife use a hair drier?

yes

 

1 hour ago, Vosser said:

Do you use a tumble drier?

yes

 

1 hour ago, Vosser said:

Electric oven?

no

 

1 hour ago, seant said:

Laundry iron , yes

yes

 

.. almost all the above equipment is used during peak power generation except the hair dryer. My wife checks the battery capacity in the morning and determines when she will take a bath/shower so that she can dry her her as soon as she is done. If batteries permit then she dries it early, else she does it during peak generation.

Edited by stoic
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1 hour ago, seant said:

Welcome,

To answer your questions,

Hairdryer ,  yes

Tumbledryer , no

Electric oven , nope

Laundry iron , yes

The iron is use mostly during the day when the sun shines so no use of the batteries , and the hair dryer is mainly use just as the sun starts to charge the batteries. Our house occupants consume about 12Kwh a day .

Same as the above, plus a pool pump and borehole pump. 12-15kwh per day (adjusted to the available power on the day)

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1 hour ago, Vosser said:

1. Does your wife use a hair drier?

Yes. But seriously... that's 2kw for like 7 or 8 minutes, and she hits the cool-air button every few seconds too. In terms of energy it's like 250Wh.

1 hour ago, Vosser said:

2. Do you use a tumble drier?

Yes, but only because we're lazy and it pretty much runs from the grid. If I were in your shoes I'd install a nice big washing line outside.

1 hour ago, Vosser said:

3. Electric oven?

Yes, but we're city dwellers and that's pretty much your only option. Gas is good for the stove top, but not so much for the oven. Again, if it is used two hours a day, and because it uses a thermostat and isn't on permanently, it's really not that big a consumer.

1 hour ago, Vosser said:

4. Laundry iron?

Yes, but again... it's a high-peak-low-energy appliance.

1 hour ago, Vosser said:

5. What is your typical kWh usage per day?

It varies. In winter and on very hot summer days (with the AC running), easily 40kwh a day (of which I offset 10kwh with solar at present). In Autumn and Spring it's more like 25kwh to 30kwh. We still have an electrical geyser (that accounts for around 4kwh, except in peak summer when the solar prefeed takes care of 100%) and the mentioned tumble drier also takes a good 3kwh. So we're pretty close to 20kwh a day. On a really good day (if the kids play outside and the TV remains off the whole day), we get down to around 13kwh.

 

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23 minutes ago, stoic said:

My wife checks the battery capacity in the morning and determines when she will take a bath/shower so that she can dry her her as soon as she is done. If batteries permit then she dries it early, else she does it during peak generation.

Kudos to your wife! She's a real PV systems engineer ;)

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Quote

 

  2 hours ago, Vosser said:

3. Electric oven?

Yes, but we're city dwellers and that's pretty much your only option. Gas is good for the stove top, but not so much for the oven. Again, if it is used two hours a day, and because it uses a thermostat and isn't on permanently, it's really not that big a consumer.

 

There's nothing wrong with a gas oven for baking. Ours has a fan system and my wife bakes all sorts of stuff.

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8 minutes ago, DeepBass9 said:

There's nothing wrong with a gas oven for baking. Ours has a fan system and my wife bakes all sorts of stuff.

I remember the old days on the farm... farmer's wives hated the gas oven. Was a pain to even light the thing (that was before electric igniters). Most of them preferred the coal stove.

🙂

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13 minutes ago, plonkster said:

I remember the old days on the farm... farmer's wives hated the gas oven. Was a pain to even light the thing (that was before electric igniters). Most of them preferred the coal stove.

🙂

We have one of those as well, and a pizza type oven (which is the best for roasting meats and making pizzas), but the coal stove takes a long time to warm up to an even heat (it burns things from the firebox side), so the gas oven is best for bread and pastries etc.

In winter though the coal stove (we use wood in it) is excellent bacuse it is nice and warm to stand next to, and you can fit about 8 pots and kettles on top, an just move them around to get the correct heat. 

Edited by DeepBass9
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Hi Vosser,

1. Does your wife use a hair drier?
sometimes

2. Do you use a tumble drier?
yes

3. Electric oven?
yes

4. Laundry iron?
yes

Apart from the above, I'm using the electric kettle, induction stove top, electric geyser, side-by-side fridge with icemaker, etc.
No pool, no Air Condition.

5. What is your typical kWh usage per day?
Around 20kWh.
But on the active day, it can be MUCH more easily. So it's good to have a slightly bigger batteries or to have a diesel genset as a backup, if needed.

image.thumb.png.2811bce983b525f3f247c481f0b24b53.png

The thing is, that I drastically oversized my PV system, but I'm not feeding into the grid, too. So, when I have no use for the solar power I simply "let it stay on the roof". It's clearly visible on the chart below: The battery was full at 10am, and since there were no major AC loads, the generation dropped.

image.thumb.png.7fc7e49721812fbe989de7492bd3cd15.png

Speaking of monitoring, I would say that for the wife it's okay to have a battery monitor (or a tablet on the wall) with just one number and some bargraph - Battery SoC.
For you, it's better to have something more sophisticated - ICC or some homebrew monitoring at least:

image.thumb.png.0a9ea281a59d1f3b9e24a5eecb8a8879.png

(Excuse the °C and Btu/h, please - there's a long story behind, why I used these symbols instead of %SoC and Ah...)

I'm using the washing machine that's combined with the heatpump tumble dryer (AEG). Here's the sample of the consumption. For one batch of laundering+drying it's cca 2kWh:
image.thumb.png.f7613675ccbb34eecc6be902bc5d158f.png

You can easily do 2 or 3 batches of laundry on one day. So it's good to size for that, especially if you plan to go fully offgrid.

GOOD LUCK!

Edited by Youda
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And this is electric owen's consumption profile:

- For the first hour of operation, it runs at 2kW for 30 minutes.
- Then there are just short 1 minute spikes.
- 1st hour uses roughly 1.2kWh of energy, but in the following hours the consumption is "almost nothing"
Therefore, it's good to prepare a few baking batches and do them all in a row.

image.thumb.png.6b277c9427ff8e58ba0241ec50e4e74a.png

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1 hour ago, Youda said:

Hi Vosser,

1. Does your wife use a hair drier?
sometimes

2. Do you use a tumble drier?
yes

3. Electric oven?
yes

4. Laundry iron?
yes

Apart from the above, I'm using the electric kettle, induction stove top, electric geyser, side-by-side fridge with icemaker, etc.
No pool, no Air Condition.

5. What is your typical kWh usage per day?
Around 20kWh.
But on the active day, it can be MUCH more easily. So it's good to have a slightly bigger batteries or to have a diesel genset as a backup, if needed.

image.thumb.png.2811bce983b525f3f247c481f0b24b53.png

The thing is, that I drastically oversized my PV system, but I'm not feeding into the grid, too. So, when I have no use for the solar power I simply "let it stay on the roof". It's clearly visible on the chart below: The battery was full at 10am, and since there were no major AC loads, the generation dropped.

image.thumb.png.7fc7e49721812fbe989de7492bd3cd15.png

Speaking of monitoring, I would say that for the wife it's okay to have a battery monitor (or a tablet on the wall) with just one number and some bargraph - Battery SoC.
For you, it's better to have something more sophisticated - ICC or some homebrew monitoring at least:

image.thumb.png.0a9ea281a59d1f3b9e24a5eecb8a8879.png

(Excuse the °C and Btu/h, please - there's a long story behind, why I used these symbols instead of %SoC and Ah...)

I'm using the washing machine that's combined with the heatpump tumble dryer (AEG). Here's the sample of the consumption. For one batch of laundering+drying it's cca 2kWh:
image.thumb.png.f7613675ccbb34eecc6be902bc5d158f.png

You can easily do 2 or 3 batches of laundry on one day. So it's good to size for that, especially if you plan to go fully offgrid.

GOOD LUCK!

I think a lot of that consumption is water heating. We use hot water from a solar geyser, or just cold water and then hang on the washing line. Our top loader uses about 200-300W when washing and then up to about 700W for a few minutes on the spin cycle.

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1 hour ago, DeepBass9 said:

I think a lot of that consumption is water heating. We use hot water from a solar geyser, or just cold water and then hang on the washing line. Our top loader uses about 200-300W when washing and then up to about 700W for a few minutes on the spin cycle.

You are right! These are the parts of the laundry cycle:

1350232630_laundrycycle.png.0982a1c79a1003082f48cf18384a660a.png

There was an option to use the hot water from the geyser, but my washing machine has just one water inlet - for the cold water. And as far as I know, there are some parts of the cycle where it needs a bit colder water - rinsing for example. Also, with wool sweaters, you have to wash them using cold water only, otherwise they shrink (The cost of this experince was R3000 that I payed for a brand new Tommy Hilfiger....oh my!)

But I know a couple of guys who installed a thermostatic valve in front of the water inlet, so it's mixing water from the geyser with the cold water. Then, the heater has not to work for so long and the laundry is done okay too.

 

@DeepBass9 what's your experience with using hot water instead of cold? And what's the temperature of the water that you use for this?

 

 

 

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Actually initially we were using 'hot' water from the solar geyser, but the washing was done in the morning, so the water wasn't really hot, more like 40 degrees. Then my wife was complaining she didn't get a steaming hot bath on washing day, so we just use cold water now. Actually the washing soap technology is quite well advanced now so cold water washing does the same job as hot more or less. This is a farm though, so we put a limited amount of  'delicates' in the washing machine.

We do have a lodge though, so we use white fine cotton linen, which needs to be spotless, and it is.  

Edited by DeepBass9
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We'll be doing an off grid installation from scratch.

I am looking at the Victron products and Pylon batteries.

What's the pros and cons between getting the Victron EasySolar-48/5000 - 70-100  and getting a standalone Victron Inverter, MPPT etc?

Am I right that the EasySolar just combines the seperate products into one panel?

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2 hours ago, Vosser said:

What's the pros and cons between getting the Victron EasySolar-48/5000 - 70-100  and getting a standalone Victron Inverter, MPPT etc?

42 minutes ago, plonkster said:

Buy the "package" that costs the least.

Yes that is good advice re. lowest cost but the price difference should be smallish.

I say buy the components separate. IF ever something has to be repaired / replaced or whatever you have room to maneuver and not take the whole shebang in. 

It boils down to personal preferences.

 

Edited by Guest
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