Jump to content

Designing a new house for solar


Recommended Posts

Hi, I'm somewhat new here (registered a while ago, but this is my first post).  I'm busy designing a house with maximum solar efficiency in mind.  I've turned the whole house on the yard so the roof faces north while the garage is still aligned with the yard / driveway that faces north-ish.  The gap due to the difference in angles (which will fall in the garage), will make for a nice little area for all the solar equipment so no actual garage space is wasted.

I pretty much have an idea of what I'm going for, but my query more relates to specific brands, how good they are and how the support is for their suppliers.  I'm planning to be mostly off-grid except for the oven.  Stove will be gas, geysers will be some sort of solar geysers connected in series and everything else will run off the solar and batteries.  I'm hoping we'll be less power intensive in the new house but the new house should be cooler since I'm designing it that way and thus we shouldn't need aircons 24/7.

I've installed a cheapish solar system in my current house (1x 5kW Axpert King, 14x 330W Renewsys panels, 8x Narada Acme F batteries) so I'm not a complete noob, but only just barely.  The installers were ok, they did a clean job and the system works fine, but I'm slightly skeptical of their advice.  While some of it seems sound, other sounds like I should have it double checked.

So here is what I'm planning thus far.  Please feel free to comment and give feedback on the brands (or setup).

Solar Panels
At least 24x 400W Mono Percium panels.  Thus far I'm mostly considering ARTsolar mostly due to them having higher efficiency and warranty and the price seems reasonable as well in comparison to other brands.

Inverter
I'm either looking at 2x 5kW or 1x 8kW.  My previous installers made a good point that if I have 2, then at least if one breaks then I'm not without power.  Thus far I'm looking at one of these two as they both have 5 year warranties.

  • Fronius Primo 8.2-1
  • Fusion 8kw Hybrid Inverter

I might want to look at pumping electricity back into the grid when that option becomes available.  I saw an option on one of these where that can be turned off, so I think I should be set with these.  Another question though:  Would I be able to connect a 5kW inverter to one of these later on or must both inverters be the same size?

Batteries
This is where I really need advice since I've been hearing opinions from all over the place.  My previous installer mentioned that Pylontec gives lots of issues and they rather install Narada batteries that has a 12 year design life and use it for off-grid daily use (still just to 50%, but they recon it will last at least 12 years).  (See why I'm skeptical)
I've seen a few threads of people having issues with PylonTech but was hoping for some more confirmation here and that those instances weren't just adhoc experiences or issues due to bad installations.

Besides the quality, the batteries obviously need to be compatible with the two inverters mentioned above.  Thus far I've been looking at these batteries:

  • Dyness Lithium-ion
  • Freedom Won Lite Home

Geysers
I've been looking at the geysers from UberSolar.

Other
Any other advice is welcome.  The db board will be located next to the inverter and batteries and I'll leave a couple of conduits running from the top floor to the garage for the wires for the solar panels.

Link to comment
Share on other sites

28 minutes ago, ViperGTI said:

Solar Panels

solar panels are solar panels, I doubt you really find bad ones these days, going for maximum efficiency usually means you are limited in space, personally I went for maximum smoke for minimum cost, in other words lowest ZAR/W ratio.

30 minutes ago, ViperGTI said:

Inverter

Don't know the units you're looking at, but would imagine that paralleled units need to be the same capacity and from the same manufacturer.
Personally I would recommend Sunsynk, we're running a Sunsynk 5kW unit and I'm happy with it. (It is a Hybrid.)

33 minutes ago, ViperGTI said:

Batteries

Certainly LiFePO4, but which manufacturer, I don't know, having seen pricing from FreedomWon, makes me think of FreedomLost, personally I'm thinking of doing a cell shipment from the far east and make up a battery to suit... (am not and neither am I related to Rockefeller, so need to watch the cents, never mind the Runts)

36 minutes ago, ViperGTI said:

Geysers

Don't know the one you're looking at, we have a evacuated tube HWC without extra wiring and heating element and it works well enough, but we have not gone through a full winter with it yet, watch this space 🙂

39 minutes ago, ViperGTI said:

Other

Don't know whether Eskom will allow feed in, but I suspect not, so don't hold your breath, some municipalities around the country may allow for it eventually, but don't expect this to become profitable. Good on the no aircon, heck no aircon here either, but sometimes, I wished...

Link to comment
Share on other sites

9 minutes ago, Kalahari Meerkat said:

Personally I would recommend Sunsynk

+1 for Sunsynk. The Fusion 8k is a whitelabelled Sunsynk inverter in any case.

10 minutes ago, Kalahari Meerkat said:

having seen pricing from FreedomWon, makes me think of FreedomLost

😁😆🤣

@ViperGTI Looks like you are building a big system, would be a shame to match it with batteries that cannot deliver strong charge/discharge rates.  What is the C rating of the  FeeedomWon or Dyness batteries? Powerforum Store still has Hubble 5.5kW 1C batteries at a very good price, seeing that you are going for local assembly on the panels you may wish to do the same with batteries, but I think that you need to be quick.

Link to comment
Share on other sites

Thanks for all the responses.  I'll try and work through everything and reply where needed.

53 minutes ago, Kalahari Meerkat said:

solar panels are solar panels, I doubt you really find bad ones these days, going for maximum efficiency usually means you are limited in space, personally I went for maximum smoke for minimum cost, in other words lowest ZAR/W ratio.

The panels that I'm looking at works out about R4.80/watt which seems about the same as the cheaper panels (looking at ArtSolar specifically).  Space isn't an issue as I've designed the roof in such a way that I can fit 3 rows of panels that are 2.1m high.  So if I put the panels for the geyser also on the north side of my roof, then there is space for about 27 panels on the north side (excluding the garage's roof).

1 hour ago, Kalahari Meerkat said:

Don't know the one you're looking at, we have a evacuated tube HWC without extra wiring and heating element and it works well enough, but we have not gone through a full winter with it yet, watch this space 🙂

I've talked to a bunch of people (plumbers) and they recommend installing two 150L solar geysers in series.  The developer that I'm working with said he's got two installed like that and in 4 years, he has maybe be once where he had to use power to heat up the geysers.

1 hour ago, Kalahari Meerkat said:

Don't know whether Eskom will allow feed in, but I suspect not, so don't hold your breath, some municipalities around the country may allow for it eventually, but don't expect this to become profitable. Good on the no aircon, heck no aircon here either, but sometimes, I wished...

Isn't that what the point is of this whole unbundling of Eskom?  To pave the way for IPPs to feed power back into the grid.
Unfortunately we use aircons a lot.  The new house will still have aircons, but with the insulation of roof overhang, I suspect we won't need to use it as much.  At least, that is the hope.

1 hour ago, YellowTapemeasure said:

Looks like you are building a big system, would be a shame to match it with batteries that cannot deliver strong charge/discharge rates.  What is the C rating of the  FeeedomWon or Dyness batteries? Powerforum Store still has Hubble 5.5kW 1C batteries at a very good price, seeing that you are going for local assembly on the panels you may wish to do the same with batteries, but I think that you need to be quick.

True, which is why I came here asking for recommendations on the brands.  I'll have a look at Hubble.  I'm going to need at least 20kW worth of battery backup to last through the night (based on current usage).  Luckily I have time since we're still sorting out the building plans before submitting them for approval.  So I can start ordering components so that it arrives around the time the building finishes.

1 hour ago, Bobster said:

Consider a heat pump. Draws a lot less power than a traditional element, works when there's no sun. Mine is backed up by the solar system.

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. :)

Link to comment
Share on other sites

2 hours ago, Kalahari Meerkat said:

Don't know the units you're looking at, but would imagine that paralleled units need to be the same capacity and from the same manufacturer.

The beauty of the sunsynk is that the aux is configurable and can be set as ac coupled input. Basically you can connect a 5kw sunsynk(or any other inverter) on the aux of the 8kw sunsynk. 

The 8kw sunsynk basically becomes the grid for the secondary inverter. The connected inverter should however be limited to 4.6kw output. 

Link to comment
Share on other sites

11 minutes ago, Achmat said:

The beauty of the sunsynk is that the aux is configurable and can be set as ac coupled input. Basically you can connect a 5kw sunsynk(or any other inverter) on the aux of the 8kw sunsynk. 

The 8kw sunsynk basically becomes the grid for the secondary inverter. The connected inverter should however be limited to 4.6kw output. 

I see in your signature that you're using Pylontech batteries.  How are they working out for you?  As I've mentioned in my original post, I've heard some bad things.

Link to comment
Share on other sites

3 minutes ago, ViperGTI said:

I see in your signature that you're using Pylontech batteries.  How are they working out for you?  As I've mentioned in my original post, I've heard some bad things.

They working out fine. Only limitation is the 0.5C charge and discharge rates. Had the 4kw geyser switch on when we had load shedding at 6am and even though there was sufficient battery to run the geyser, my bedroom aircon was on at the time and the total load was 6kw. The BMS of the pylontech disconnected as it was drawing more than 5.5kW from the batteries. My plan is to eventually increase the battery bank to 8 x 3.5kWh pylontech batteries so the 0.5C rating will be a non issue. 

Link to comment
Share on other sites

12 minutes ago, ViperGTI said:

I see in your signature that you're using Pylontech batteries.  How are they working out for you?  As I've mentioned in my original post, I've heard some bad things.

My own 3x US3000B haven't given me any issues in the past 7 months that I have owned them, I can't complain. I chose them based on their promising test results vs other premium brands (like BYD).

At the same time, I have seen some eyeopener photos of their insides though, here on the forum. So today, if I were buying, I would probably give Hubble the thumbs-up.

Edit: Then again, I have a tiny 5k system, so own my needs dwarf yours.

Edited by YellowTapemeasure
Link to comment
Share on other sites

9 minutes ago, YellowTapemeasure said:

My own 3x US3000B haven't given me any issues in the past 7 months that I have owned them, I can't complain. I chose them based on their promising test results vs other premium brands (like BYD).

At the same time, I have seen some eyeopener photos of their insides though, here on the forum. So today, if I were buying, I would probably give Hubble the thumbs-up.

Edit: Then again, I have a tiny 5k system, so own my needs dwarf yours.

Has your SOH dropped yet on the inverter LiBMS screen? 

Mine dropped to 99% SOH after 5 months. 

Link to comment
Share on other sites

24 minutes ago, Achmat said:

How is the battery test center managing to discharge them at 1C if the BMS limits this to 0.5C? 

Is there a report on the capacity discharged / time? I only see one with cycles in their methodology, 3x per day, and at Southern hemisphere temperatures.. Why do you say that they are discharging them at 1C? And if they are, maybe they have a bank in parallel?

They have been charging and discharging the US 2000B since phase 2 -- July 2017, with no issues, and data suggests a "SOH of ~82% after ~1,940 cycles". It was pretty good for me at the time.

Edited by YellowTapemeasure
typo
Link to comment
Share on other sites

4 minutes ago, YellowTapemeasure said:

Is there a report on the capacity discharged / time? I only see one with cycles in their methodology, 3x per day, and at Southern hemisphere temperatures.. Why do you say that they are discharging them at 1C? And if they are, maybe they have a bank in parallel?

They have been charging and discharging the US 200B since phase 2 -- July 2017,l with no issues, and data suggests a "SOH of ~82% after ~1,940 cycles". It was pretty good for me at the time.

Could be that they have more than one battery connected. I'm assuming it's one US2000 battery as they are discharging it at 2.4kw and then 1.88kw alternating between the two rates. 

My own estimate is to get mine to 4 500 cycles before reaching 80% and only discharging to 30% SOC. 

Link to comment
Share on other sites

14 hours ago, ViperGTI said:

Hi, I'm somewhat new here (registered a while ago, but this is my first post).  I'm busy designing a house with maximum solar efficiency in mind.  I've turned the whole house on the yard so the roof faces north while the garage is still aligned with the yard / driveway that faces north-ish.  The gap due to the difference in angles (which will fall in the garage), will make for a nice little area for all the solar equipment so no actual garage space is wasted.

I pretty much have an idea of what I'm going for, but my query more relates to specific brands, how good they are and how the support is for their suppliers.  I'm planning to be mostly off-grid except for the oven.  Stove will be gas, geysers will be some sort of solar geysers connected in series and everything else will run off the solar and batteries.  I'm hoping we'll be less power intensive in the new house but the new house should be cooler since I'm designing it that way and thus we shouldn't need aircons 24/7.

I've installed a cheapish solar system in my current house (1x 5kW Axpert King, 14x 330W Renewsys panels, 8x Narada Acme F batteries) so I'm not a complete noob, but only just barely.  The installers were ok, they did a clean job and the system works fine, but I'm slightly skeptical of their advice.  While some of it seems sound, other sounds like I should have it double checked.

So here is what I'm planning thus far.  Please feel free to comment and give feedback on the brands (or setup).

Solar Panels
At least 24x 400W Mono Percium panels.  Thus far I'm mostly considering ARTsolar mostly due to them having higher efficiency and warranty and the price seems reasonable as well in comparison to other brands.

Inverter
I'm either looking at 2x 5kW or 1x 8kW.  My previous installers made a good point that if I have 2, then at least if one breaks then I'm not without power.  Thus far I'm looking at one of these two as they both have 5 year warranties.

  • Fronius Primo 8.2-1
  • Fusion 8kw Hybrid Inverter

I might want to look at pumping electricity back into the grid when that option becomes available.  I saw an option on one of these where that can be turned off, so I think I should be set with these.  Another question though:  Would I be able to connect a 5kW inverter to one of these later on or must both inverters be the same size?

Batteries
This is where I really need advice since I've been hearing opinions from all over the place.  My previous installer mentioned that Pylontec gives lots of issues and they rather install Narada batteries that has a 12 year design life and use it for off-grid daily use (still just to 50%, but they recon it will last at least 12 years).  (See why I'm skeptical)
I've seen a few threads of people having issues with PylonTech but was hoping for some more confirmation here and that those instances weren't just adhoc experiences or issues due to bad installations.

Besides the quality, the batteries obviously need to be compatible with the two inverters mentioned above.  Thus far I've been looking at these batteries:

  • Dyness Lithium-ion
  • Freedom Won Lite Home

Geysers
I've been looking at the geysers from UberSolar.

Other
Any other advice is welcome.  The db board will be located next to the inverter and batteries and I'll leave a couple of conduits running from the top floor to the garage for the wires for the solar panels.

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.

 

Link to comment
Share on other sites

So based on my 1% drop in SOH in 5 months, that is roughly 2,5 % per year, gives me 8 years to reach 80% SOH and just under 3000 cycles. I bought my Pylontech 2000 batteries at R15,000 each, so that each cycle is roughly R10, which at April 1st prices is 4 kWh’s , which is about the same as my battery capacity  ( at 80% ) capacity, which brings me to my conclusion, that you only need enough batteries for load shedding, do you guys agree is a fair assumption , granted the batteries will still have 80% capacity and however many years they last.

Link to comment
Share on other sites

18 minutes ago, Tariq said:

So based on my 1% drop in SOH in 5 months, that is roughly 2,5 % per year, gives me 8 years to reach 80% SOH and just under 3000 cycles. I bought my Pylontech 2000 batteries at R15,000 each, so that each cycle is roughly R10, which at April 1st prices is 4 kWh’s , which is about the same as my battery capacity  ( at 80% ) capacity, which brings me to my conclusion, that you only need enough batteries for load shedding, do you guys agree is a fair assumption , granted the batteries will still have 80% capacity and however many years they last.

Similar to my calculations. Granted that the batteries will not be entirely dead. Only that your 3.5kWh battery will now be a 2.8kWh battery 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...