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Not all correct...

 

Moving over to gas reduces the load on Eskom, less likelihood to get load shedded.

Moving over to gas reduces the load you put onto a inverter/battery should you have been load shedded, making those expensive batteries last longer when things have gone pair shaped at Eskom.

Yes, you at the whim of Gas supply, but a kitchen stove you will normally drive off a 18 or 48Kg bottle... They (48Kg) last 12-18 months for us, and oh you can have these large bottles delivered, so it's a cll and guy shows up with refilled bottle and takes the old empty one. PS don't tell your wife... she will love cooking with gas.

G

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2 hours ago, PeterP said:

Reducing consumption of electricity by changing to gas cooking makes no sense unless we're looking at 100% off-grid set-up with no Eskom supply. Firstly, you incur capital expenditure setting it all up, secondly, you will merely move the expense of electricity over to purchasing of gas, thirdly, you are now at the whims of gas supply and travelling around to get it plus over time it is likely to go up in price and lastly you will continue to contribute CO2. Unless you enjoy cooking on gas or already have a gas stove, I would not change, rather spend a little more on the PV system.

 

agreed. @plonkster has some calculations somewhere that show how much gas you need to boil 1L of water, or something like that, which basically shows that gas cost about the same as Eskom for cooking. The only two real advantages of gas over Eskom is that you have instant hot water (at limited temperatures) and it still works when all other power sources fail ;)

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2 hours ago, georgelza said:

Not all correct...

 

Moving over to gas reduces the load on Eskom, less likelihood to get load shedded.

Moving over to gas reduces the load you put onto a inverter/battery should you have been load shedded, making those expensive batteries last longer when things have gone pair shaped at Eskom.

Yes, you at the whim of Gas supply, but a kitchen stove you will normally drive off a 18 or 48Kg bottle... They (48Kg) last 12-18 months for us, and oh you can have these large bottles delivered, so it's a cll and guy shows up with refilled bottle and takes the old empty one. PS don't tell your wife... she will love cooking with gas.

G

But there's almost 0 cost savings in gas. And we battle to get gas almost every 2nd winter, even with more and more gas companies popping up every now and then. 

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2 hours ago, georgelza said:

Moving over to gas reduces the load on Eskom, less likelihood to get load shedded.

Not even a drop in the dam difference. 🙂 

2 hours ago, georgelza said:

Moving over to gas reduces the load you put onto a inverter/battery should you have been load shedded, making those expensive batteries last longer when things have gone pair shaped at Eskom.

That makes sense yes. Lower costs of the equipment and yes, get a large bottle or two of gas.

Because with load shedding and a stove / oven on batts, you will cry in a few years time. 

Be wise about gas / Eskom / solar.

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5 hours ago, PeterP said:

changing to gas cooking makes no sense

Agreed. In terms of cost it is not cheaper. A 9kg bottle of gas has the equivalent of around 113Kwh of energy (you can work it by googling the calorific content of LPG and converting). That shows that per unit of energy gas costs very close to electricity, so it all comes down to the efficiency (how much heat makes it from the heating element into the food), and my research on that suggests that electricity is up to twice as efficient (if you a correctly sized utensil and so forth).

Regarding CO2, I think there is a case to be made for gas. It is much lighter on the environment than coal. Burning gas at the point of consumption vs coal on the other side of the country... I think gas wins. Also, CO2 is not our biggest worry. CO2 is a fairly friendly gas (plants can use it). The stuff we are worried about is the Nitrous oxides (acid rain) and the carbon monoxides and all those other carcinogens. Gas burns fairly clean.

I do agree however that gas is more for people who like cooking on gas. It really is a pleasure to cook on gas. It also makes you independent of the grid, so if you want to be able to cook when there is a grid outage, using gas is going to be much cheaper than attempting to put up PV that will drive a stove!

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3 hours ago, SilverNodashi said:

But there's almost 0 cost savings in gas. And we battle to get gas almost every 2nd winter, even with more and more gas companies popping up every now and then. 

Not everything for me is about the cost saving, it's the independence... the not relying on Eskom.

G

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1 hour ago, georgelza said:

Not everything for me is about the cost saving, it's the independence... the not relying on Eskom.

G

With solar PV you won't even be relying on the gas-man. We cook with solar power on electric stove, it works and we've never not had power for this, it may have shortened the available power over night as batteries were depleted more than if we didn't cook, but using a stove is typically quite quick so it doesn't actually consume that much - the oven can be a killer though. But each installation is different, in an ideal world we all have enough budget to install sufficient battery to run house over night incl. cooking and geyser boost in the morning - but not all budgets allow this.

The main point I wanted to make was to not CHANGE OUT an electric stove for gas when converting to Solar PV unless there are special circumstances - if you have gas already, by all means keep it.

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I like cooking on gas it's instantly hot and it's just convenient, and it takes the kettle out of the equation too. Yes it's not cheaper to run than an electric stove on Eskom. Though running an electric stove on solar while cooking for a family, I can't see it being more economical that gas. With needing to have extra autonomy built in meaning more pannels larger battery bank possibly additional charge controller , or then you need a genset for the extended cloudy weather and your average 5kva genset ain't going to charge the batteries and run the stove . That or live on take aways.  An extra pylon battery is going to be give or take 20k , that's a real nice stove top and gas for a long time not to mention the 4 or 6 300w pannels to go with it

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3 minutes ago, seant said:

An extra pylon battery is going to be give or take 20k , that's a real nice stove top and gas for a long time not to mention the 4 or 6 300w pannels to go with it

And for really nice, you can get a gas/electric hybrid. Using the electric when there is ESKOM.

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1 hour ago, PeterP said:

With solar PV you won't even be relying on the gas-man. We cook with solar power on electric stove, it works and we've never not had power for this, it may have shortened the available power over night as batteries were depleted more than if we didn't cook, but using a stove is typically quite quick so it doesn't actually consume that much - the oven can be a killer though. But each installation is different, in an ideal world we all have enough budget to install sufficient battery to run house over night incl. cooking and geyser boost in the morning - but not all budgets allow this.

The main point I wanted to make was to not CHANGE OUT an electric stove for gas when converting to Solar PV unless there are special circumstances - if you have gas already, by all means keep it.

I am with you on this, and thus don't have gas, other than the portable gas heater. 

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17 minutes ago, seant said:

I like cooking on gas it's instantly hot and it's just convenient, and it takes the kettle out of the equation too. Yes it's not cheaper to run than an electric stove on Eskom. Though running an electric stove on solar while cooking for a family, I can't see it being more economical that gas. With needing to have extra autonomy built in meaning more pannels larger battery bank possibly additional charge controller , or then you need a genset for the extended cloudy weather and your average 5kva genset ain't going to charge the batteries and run the stove . That or live on take aways.  An extra pylon battery is going to be give or take 20k , that's a real nice stove top and gas for a long time not to mention the 4 or 6 300w pannels to go with it

Our induction plates also give instant heat. A gas stove + installation would set me back about R15K and then I need to buy gas every 6-8 months. At that point I realized it's easier to just extend my existing setup and use it. It turns out that we generally have the plates on 400W or 800W when cooking dinner. The kettle boils on 1300W, albeit a bit longer than 2000W but that's fine. 

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I hadn't thought about induction stoves. Though spending R200 about every 6months on a 9kg bottle of gas won't break the budget. At a thumb suck of R12k over 20 years on gas it's still cheaper than changing a pylon battery pack, if they last that long

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31 minutes ago, phil.g00 said:

And for really nice, you can get a gas/electric hybrid. Using the electric when there is ESKOM.

 

21 minutes ago, SilverNodashi said:

The main point I wanted to make was to not CHANGE OUT an electric stove for gas when converting to Solar PV unless there are special circumstances - if you have gas already, by all means keep it.

Very practical, of course.

There are sometimes political reasons to spend money on something that doesn't directly seem to benefit your own personal goals in a family life.

You're spending 100's of K on the roof, sometimes the boss want's something shiny, or your budget will get a lot harder to justify.

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1 hour ago, seant said:

I hadn't thought about induction stoves.

I have forgotten about them too!!!
interesting to see the MPPT backing off / pushing all the time when they draw say 800w - then zero - then 800w - rinse repeat. Just like a Microwave.

Two thoughts:
We have 2 plates - Snappy Chef and a Morphy Richards. Snappy is better, Morphy is not so lekker. My wife hates them both. Always burns something.
My Mother on the other hand loves hers, cooks and bakes anything on hers like a pro chef - have not told the wife yet.

So if you want, ask the wife / our if you are the cooker, to try before you buy as the makes are vastly different.

And the way they are used by the cooker ... not exactly like a electric / gas hob.

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How much power do induction stoves draw? Do you need special pots, or do they work on any metal?

Incidentally my only experience of the last round of load shedding was when I went to the supplier to refill my gas bottle, but it couldn't be filled due to no power to pump the gas.

Edited by DeepBass9
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1 hour ago, DeepBass9 said:

How much power do induction stoves draw?

Typically 2000 W per element (at maximum heating). I'm happy with a single element one that plugs into a standard outlet powered by my solar inverter, and cost under AU$50 (about R500). It sits on top of the stove, which I've not used (apart from the griller) since I bought the induction cooker.

Quote

Do you need special pots, or do they work on any metal?

The pot has to have iron or steel in the base, though I think not stainless steel. All new cookware seems to come with a glow-plug-like symbol if it is suitable. We used old cast iron pots for a while, then treated ourselves to a new Woll 5 piece set we purchased online at a steep discount. They're still doing fine after a few years, though the wok which we use almost daily has lost some of its non-stick coating. Still very usable though.

I highly recommend induction cooking.

[ Edit : added "standard outlet". I should have added that my cheap model switches on an off below 1000 W, but my understanding is that normal models PWM down to much lower power levels. ] 

Edited by Coulomb
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1 hour ago, DeepBass9 said:

How much power do induction stoves draw? Do you need special pots, or do they work on any metal?

Incidentally my only experience of the last round of load shedding was when I went to the supplier to refill my gas bottle, but it couldn't be filled due to no power to pump the gas.

Last time I checked an induction stove cost in the region of R10K. We hardly use the oven so I just got some induction plates. No fancy name brand. My brother's snappy chef lasted, probably, 3 months more then the warranty, so I decided to buy the cheapest one I could get at Game. That was 3 or 4 years ago and it's still working quite well. 

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Just now, DeepBass9 said:

 simmering a pot?

400 W, depending on how much liquid of course.

Power is power. The savings come from not having to heat up an element and its necessary electrical insulation. You still need to heat up the pot of course, but that's about half a minute.

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Hi 

I recently installed my solar system 

Axpert 5kva inverter 2x series of 3x 355w pannels

8x 100ah bateries 2x bank of 4

So it working alright

But would like to know how mutch energy i generate per hour on the stats i get from watchpower

This is a extract of an hour of pv power i got what is the total i got in that hour the maths im doing doesnt make sense and hope some one can explain it to melarge.IMG-20190425-WA0009.jpg.1c3128903eb69607235bcca91da38c72.jpg

This is what my actual was during the same period except fot to power going to the bateries

large.IMG-20190425-WA0010.jpeg.9e7d1e03a6165d9f7de44efcc533b6b7.jpeg

Edited by Deanvd
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12 hours ago, Deanvd said:

Hi 

I recently installed my solar system 

Axpert 5kva inverter 2x series of 3x 355w pannels

8x 100ah bateries 2x bank of 4

So it working alright

But would like to know how mutch energy i generate per hour on the stats i get from watchpower

This is a extract of an hour of pv power i got what is the total i got in that hour the maths im doing doesnt make sense and hope some one can explain it to melarge.IMG-20190425-WA0009.jpg.1c3128903eb69607235bcca91da38c72.jpg

This is what my actual was during the same period except fot to power going to the bateries

 

That measurement from watchpower was done every 5 minutes, roughly, so you need to add them together to get an hourly view.

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22 hours ago, SilverNodashi said:

so you need to add them together to get an hourly view

Actually, average the figures, so add them and divide by the number of samples in one hour. From your figures, that might be say 1600 W, or 1.6 kW, so that would be 1.6 kWh.

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