I run two houses wholly offgrid with Pylons.

One property has been running since November 2018 and comprises 2 parallel banks of 4 Pylons (one bank is 2.4s and the other bank is 3.5s). They are now sitting on 98% SOH.

My other property has only been running since November 2020 and has 2 parallel banks of 2 Pythons. They are still at 100% SOH. During the weeks of rainy weather we drew these down to shutoff several times.

I'm really not concerned about longevity since I am convinced that we will be replacing the current technology with something far better well before planned battery end of life.



 

hi @PaulinNorthcliff, the house with the 98% SOH, how far down do you discharge your batteries and assume being off grid you cycle the batteries daily

2 hours ago, Erastus said:

If you do it all on a "new" house why do you still use old fashioned methods of electricity in the house? When I did my house some years ago I did it by designing the electricity lay out different and by doing that I got away with saving on equipment that is costly.  Just think not the old way of wiring. It might cost a few R more on wiring but will safe plenty on expensive equipment.

Unless you want to brag with equipment that cost a fortune and expensive in the long as well as short run.

 

Care to expand on this> Did you run DC circuits for 12V?

1 hour ago, Tariq said:

hi @PaulinNorthcliff, the house with the 98% SOH, how far down do you discharge your batteries and assume being off grid you cycle the batteries daily

Thinking a bit on this and I think the first percentage drop will be quicker than subsequent drops. For example, dripping capacity from 3.5kWh to 3.49kWh it would show 100% SoH to 99% SoH. Capacity would need to go below 3.465kWh for it to go below 99% SOH and then to 3.43kWh to get to 98% SOH. 

@ViperGTI. Something to think about in your planning. Installing a stove top with LPG and electric plates combined.It will cost more but it is worth the layout. We started with LPG only before installing solar. Later we leaned that we have extra electricity that we don't use. I then installed a Elba stove with 2 plates. These stoves use power depending what your setting is, no1. Uses only 100Watt going up to 1000Watt at setting 6. The big plate is 100 to 2000 Watt. These plates draw a constant current, so no on and off switching. We now cook more with electricity than LPG now. 

14 hours ago, ViperGTI said:

I've looked into it, but there are some issues... think it requires maintenance quite often or only lasts for a certain period.  Can't remember now, just that I looked into it and then dismissed the idea.  Besides I doubt that it can use less power than a solar geyser (which uses none) unless it starts generating its own electricity somehow. 

They don't use their own electricity of course, but the way I see it they use a lot less and so on gloomy days I can still run the heat pump from stored power. In fact mine starts up at 6 ish before I have any useful PV, so it runs off batteries for a while before we get enough PV to charge batteries and service the load. If I did that with a conventional geyser I'd draw more power for longer and take a bigger chunk out of the battery. 

They do need some care. You need to open it up once a year or so and clean out leaves that can accumulate. There's a filter that needs cleaning too. It's not a lot if you're a handy person.

No solution is perfect. I've had a solar geyser here in Johannesburg and it worked, but it wasn't so great on gloomy days. With my current setup, most days I run the heat pump for free.

16 hours ago, Kalahari Meerkat said:

FreedomSquandered seems to be 15 cell design, which I don't like, but otherwise specs and 10 year Warranty seems also not too bad, still I'll do my sums and probably sea freight some cells, its not on the cards for me right now anyway...

Why don't you like this design?

If I were building a house from scratch, I would do the following;

1) Split Essential and non-essential DB's

2) Build a utility room that contains the DB's and has space for

a) Batteries

b) Inverter(s)

c) limits electrical run from PV panels

d) Well ventilated

e) Geyser to run from evacuated tubes + elec

f) Gas stove (I see someone suggested gas-electric)

g) Place for a water tank to collect rain water, 20 000l minimum, + pressure pump for watering garden, filling pool.

h) WiFi repeaters in the ceiling, connected by cable

 

I live in a house built in the 50's, so to get all the above to fit is a mission!

Edited March 9, 20215 yr by FixAMess

28 minutes ago, FixAMess said:

Why don't you like this design?

For LiFePo4 batteries a 16 cell design makes more sense, yes with one less cell you are only 3.x volt lower for the whole battery, but also 1/16 of energy capacity less than you should be/could have. But apparently, it is a 16 cell battery, but their spec sheet doesn't state whether it is or isn't.

7 minutes ago, FixAMess said:

If I were building a house from scratch, I would do the following;

1) Split Essential and non-essential DB's

2) Build a utility room that contains the DB's and has space for

a) Batteries

b) Inverter(s)

c) limits electrical run from PV panels

d) Well ventilated

e) Geyser to run from evacuated tubes + elec

f) Gas stove (I see someone suggested gas-electric)

g) Place for a water tank to collect rain water, 20 000l minimum, + pressure pump for watering garden, filling pool.

h) WiFi repeaters in the ceiling, connected by cable

 

I live in a house built in the 50's, so to get all the above to fit is a mission!

Oh, I'm already planning almost all of this except for the split DBs, but I can maybe look into that.  The only real non-essentials that I can think of would be the pool pump and pressure pumps (for rain and grey water).

2.a+b:  I have dedicated space in the garage that doesn't take up any of the garage space.  I could close it if I really want but I figured there would be more ventilation if I just leave everything open.

2.c:  This is a bit hard as the PV panels are on the roof of the top floor.

2.f:  Gas stove already planned, but with electric oven.  I was looking into full gas stove/oven, but decided to rather stick to electric.

2.g: Planning for both rain water and gray water collection with a split outlet for the gray water to choose if I want to collect it or just let it run back to municipality.  I'll actually need two of each (one on each side of the house).

2.h: Only planning for a single conduit from the bottom floor to the top floor.

@Erastus What ideas did you have and what expensive equipment would I be able to cut out?  The main things are the inverter, batteries and panels and I don't see a way to cut those out.

58 minutes ago, FixAMess said:

If I were building a house from scratch, I would do the following;

1) Split Essential and non-essential DB's

2) Build a utility room that contains the DB's and has space for

a) Batteries

b) Inverter(s)

c) limits electrical run from PV panels

d) Well ventilated

e) Geyser to run from evacuated tubes + elec

f) Gas stove (I see someone suggested gas-electric)

g) Place for a water tank to collect rain water, 20 000l minimum, + pressure pump for watering garden, filling pool.

h) WiFi repeaters in the ceiling, connected by cable

 

I live in a house built in the 50's, so to get all the above to fit is a mission!

Good list, for me, I'd add a borehole with a solar-friendly pump.

4 hours ago, Tariq said:

hi @PaulinNorthcliff, the house with the 98% SOH, how far down do you discharge your batteries and assume being off grid you cycle the batteries daily

When I struggled with my old Goodwe there were one or two occasions when the BMS shut the batteries off to save them... 18% at one stage, although the Goodwe was set to pull the plug at 20%. This should still be within the Pylon's safe space of 10% SOC.

Sorry @PaulinNorthcliff, I meant what DOD do you take the batteries down to on a daily basis

23 minutes ago, Tariq said:

Sorry @PaulinNorthcliff, I meant what DOD do you take the batteries down to on a daily basis

It very much depends.

Typically no lower than 20% SOC. If I charge up early and then the sun shines until sundown and we enter the night at 100%, then the system at my house is on 65-70% SOC by sunup.

At my office (where we have almost half the batteries - because nobody is likely to put on the tumble drier, AND the dishwasher, AND the washing machine at night), then we hit 30-37% SOC by sunup.

Edited March 9, 20215 yr by PaulinNorthcliff

7 hours ago, ViperGTI said:

Oh, I'm already planning almost all of this except for the split DBs, but I can maybe look into that.  The only real non-essentials that I can think of would be the pool pump and pressure pumps (for rain and grey water).

2.a+b:  I have dedicated space in the garage that doesn't take up any of the garage space.  I could close it if I really want but I figured there would be more ventilation if I just leave everything open.

2.c:  This is a bit hard as the PV panels are on the roof of the top floor.

2.f:  Gas stove already planned, but with electric oven.  I was looking into full gas stove/oven, but decided to rather stick to electric.

2.g: Planning for both rain water and gray water collection with a split outlet for the gray water to choose if I want to collect it or just let it run back to municipality.  I'll actually need two of each (one on each side of the house).

2.h: Only planning for a single conduit from the bottom floor to the top floor.

@Erastus What ideas did you have and what expensive equipment would I be able to cut out?  The main things are the inverter, batteries and panels and I don't see a way to cut those out.

DO you mind to send me your pdf of your plan then I can fully assist you.  I when the architect did my house I insisted on a different approach with DB's etc.  No electrical firm wanted to do it. So I designed it installed it and had it approved.  Today I do not use fancy batteries and I save thousands.

Once I have it I will fully developed it for you.  It is difficult to discuss a length of wire.  Also I am not good talking to humans better to computers so I would advice you and then you are welcome to put it on the board and all can have a ball.

I can assure you with a little extra wiring you will save more on batteries and I will discuss it and explain it to you in full.  My house have 5 DB's and two external ones.  Therefore my solar system done not have all the boxes and channels and and and you see on foto's

 

9 hours ago, YellowTapemeasure said:

Care to expand on this> Did you run DC circuits for 12V?

A combination.  I mentioned somewhere I have 5 DB's in my house. The average electricians night mare.  Therefore in Cpt I have one guy that I make use of. He now trusts me as I helped many people moving to solar. My COC's normally take 10 minute with them as they fully understand what I am doing and starting to convince others to follow suit.

8 minutes ago, Erastus said:

A combination.  I mentioned somewhere I have 5 DB's in my house. The average electricians night mare.  Therefore in Cpt I have one guy that I make use of. He now trusts me as I helped many people moving to solar. My COC's normally take 10 minute with them as they fully understand what I am doing and starting to convince others to follow suit.

I'd love to know more, and when you have the time, I am patient. We need rebellious, challenging Galileos like you, otherwise we may all still believe in Aristotle's teachings on falling bodies and the papal view on the earth being the centre of the universe. 😉

37 minutes ago, YellowTapemeasure said:

I'd love to know more, and when you have the time, I am patient. We need rebellious, challenging Galileos like you, otherwise we may all still believe in Aristotle's teachings on falling bodies and the papal view on the earth being the centre of the universe. 😉

I just have one very bad part of me and I talk better to computers than humans.  But I will sit and draw my system on a sketch one day.   Rebel I am fir sure.

The council every two/three weeks came to inspect my house for what I was doing but in the end they got tired.  😇 I personally believe in time to come we all will only have low voltage DC homes with a few sockets AC. That is if we have leaders and not followers which seem to be so common(algemeen).

Edited March 9, 20215 yr by Erastus

1 hour ago, Erastus said:

I just have one very bad part of me and I talk better to computers than humans.  But I will sit and draw my system on a sketch one day.   Rebel I am fir sure.

The council every two/three weeks came to inspect my house for what I was doing but in the end they got tired.  😇 I personally believe in time to come we all will only have low voltage DC homes with a few sockets AC. That is if we have leaders and not followers which seem to be so common(algemeen).

Mooi so, ek sien uit daarna!

Edited March 9, 20215 yr by YellowTapemeasure

22 hours ago, ViperGTI said:

2.f:  Gas stove already planned, but with electric oven.  I was looking into full gas stove/oven, but decided to rather stick to electric.

If you go full gas then the stove still needs some electricity but not much. It needs electricity for the sparker, for the lamp in the oven, for the fan in the oven - but these are minor draws and the stove can be backed up.

If you go gas hob, electric oven then the whole stove will have to be on the non-backed up DB and you will need to have some kind of ignition device handy for the gas hob during outages.

So I had a quick chat with my installer (the one who did my current house) and gave them the rundown of what I'm planning to hear their opinion as well.

They're big fans of the Axpert King inverters so their recommendation is to have two of them and join them together.  I'm still rather looking at my original list but with Sunsylk also in the running.

For batteries however, they strongly discourage Dyness due to warranty not being great, the Hubble they don't really have strong opinions on (they think it is ok, but not great) and strongly recommend on of the following Lithium batteries:

• Blue Nova
• Freedom Won
• Narada

We've already covered the Freedom Won earlier in this thread (and they also say it is extremely expensive).  Does anyone have any opinions or experience with the other two brands mentioned.

From what I can see on Blue Nova, it seems that it can be discharged to 100% DoD, also comes with 10 year warranty and 2x 5.2kW costs about the same as the 10kW Freedom Won.  They do seem to go on special from time to time like at the moment it is available for R32k per 5.2kW at LiveStainable.

https://www.bluenova.co.za/wp-content/uploads/2020/07/BN52V-100-5.2k-DU.pdf