Jump to content

Figuring out a Hybrid setup


bruce wayne
 Share

Recommended Posts

hi all

please forgive me - i am totally (electrically) technically unaware. i have been reading thru these forums, but now have more questions than answers :-(

i have a standard house, with daytime consumption comprising pool pump, fridge, freezer, computer - about 3,500 W.

i would like a hybrid system that can :
* use daytime PV where possible 
* if i exceed my generated PV, then source the balance from battery/grid intelligently (don't trip if i exceed - once a week the tumbledryer, iron and washing machine will also be running)
* at night source from battery first (e.g. from 22h00 - 06h00)
* have some load shedding capacity - e.g. survive at least 3 hours with no grid (day or night)
* at least have ability to feed back to grid in future (currently just doesn't seem to make sense)

what i've discovered sofar :
* Infini 5kW seems great, but expensive and scarce
* Infini 3kW seems next best, but limited to 3kW (naturally) - it has a low "tripping point"?
* Axpert 5 also popular, but cannot intelligently distribute between PV and grid/battery 

my questions (sorry if this has been covered a million times already)
1) i can't seem to get ballpark pricing for standard, all-inclusive installations e.g. infini 3 plus panels plus batteries, or infini 5, or Axpert 5?
2) is it recommended to draw from battery every nite i.o. from grid? you will draw less from grid, but how will this affect the batteries in the longterm?
3) i have a prepaid meter - what does this mean for my proposed installation? what can and can't i do with it?
4) any recommended installers in the cape town northern suburbs area? 
5) what permissions do i need from municipality? if i don't?
6) any other recommended setups that i should investigate?

many thanks for your response - you guys seem remarkably patient with all of us noobs that keep asking the same questions ...

Link to comment
Share on other sites

Welcome Bruce. The guys will be around soon to answer.

What I can say for the moment, :
Prepaid meters and grid tie - feeding back to the grid - does not work well.
You do not want to charge batteries using the grid, unless it is a emergency.
What are your loads a night, for you do not want to go below 50% DOD on your batteries.
We have a few installers here that can help.
If you ask Plonkster and me, investigate VICTRON!!! :D

Link to comment
Share on other sites

welcome to the site,

 

i run my entire home  on an Imeon 3.6 hybrid inverter. during the day my load is supplied by pv on the roof, night time from my battery bank. you are going to need  a decent battery bank and sufficient panels . The Infini is a great unit, the 5 kw is somewhat pricey but now available, the Imeon is a 3kw but can run full steam up to 6kw if solar, battery and pv are available. System prices can be anything from R89k up to R230K dependent on the configuration. The Imeon system seems to be the most popular i have installed over the last year, around 57 installs in the last 4 months just on Imeon, I think the Infini 5kw plus will give it a run for its money seeing that it can handle 10kw of pv.... oh and by the way my Eskom bill i max R75 per month which i hope to cancel with the addition of a 2kw wind turbine ...

Link to comment
Share on other sites

Nice JDP!!!

After reducing our loads over a few years, SWAMBO and hers in line (I like to believe), we are at times <R750pm ... which makes it extremely difficult to justify more solar expenses ... for now.

Link to comment
Share on other sites

Hi BatBoy,

You looking for a Hybrid inverter and nothing else.

Currently your best option would be the Imeon, as the 5kw Infini price is nuts :(. There is also other options, but most of them have battery voltages from 96V up to 192V !!! (IngeCon or AEC)

Just make sure your really want to run ALL night from batteries, as this will put a huge strain on the bank and your wallet.

Just make sure you understand the limitations of each Inverter.

The Imeon can do 6kw, but only when it runs from mains. During a power failure you limited to 3kw, so plan accordingly to avoid dissapointment.

Regarding the feedback to the grid, it is not worth it IMO. According to City Of Cape Town, you have to apply for permission for a solar PV system connected to the grid, period. Even if you NOT planning to feed power back to the grid. So far I know the Imeon is an approved unit, but the paper exersize is just not worth it.

For your own safety and others, just make sure you get a COC from your installer or electrician. Also inform your home insurer to make sure they aware of the PV system.

Link to comment
Share on other sites

Sorry, thread hijack imminent.

35 minutes ago, Wetkit said:

According to City Of Cape Town, you have to apply for permission for a solar PV system connected to the grid, period. Even if you are NOT planning to feed power back to the grid.

The above caught my eye. So each and every say Axpert / Infinity / Imeon  / Multiplus installation needs to have permission, even though they do not feed back to the grid, just for being connected to the grid?

And what if one has an off-grid installation, system nowhere connected to the grid, separate circuits, does one still need to apply for permission?

Link to comment
Share on other sites

hahaha - wondering how long before "the bat" came out :-)

 

thank you all for your responses - you've been very helpful (and patient sofar :-)  )

 

wetkit - so you are suggesting an imeon e3.6, without battery?  i've played with idea since batteries are expensive.  

* so this setup would use PV when it can, otherwsie just seamlessly pull from the grid?

* and would the imeon still provide PV when grid is off e.g. loadshedding (during sunshine hours of course)?

* what would a ballpark figure for an imeon 3.6 plus panels and installment set me back? i mean is it closer to R10K, 50K or 100K ?

* and would the imeon give me some future-proofing - could i hook up batteries when i wanted to, and if COCT changed their policy of feeding back to grid - could I?

 

i don't need batteries ALL night - was just wondering if it would be wise/cost-effective to drain the batteries first (at least to say 50%) before pulling from the grid.  load at night is light, 

and i guess batteries are also attractive for load-shedding situations ...

 

 

Link to comment
Share on other sites

16 minutes ago, The Terrible Triplett said:

Sorry, thread hijack imminent.

The above caught my eye. So each and every say Axpert / Infinity / Imeon  / Multiplus installation needs to have permission, even though they do not feed back to the grid, just for being connected to the grid?

And what if one has an off-grid installation, system nowhere connected to the grid, separate circuits, does one still need to apply for permission?

If you get your bill from City of Cape Town and have a Solar PV connected to the grid, you need to register.

Best way to get around this is to have your system off-grid by having a change-over switch to switch between solar and grid power.

Link to comment
Share on other sites

I think you can run the Imeon without a battery bank, but that will not help when load shedding hits you.

Perhaps Mike can answer you better, as I do not know the Imeon that well.

You looking for about R30k for the Imeon, R30k for 3kw PV and say another R30k for about 300Ah storage. Say another R10k for installation.

This is only ballpark figures, as all will depend on your specific requirments and site.

Link to comment
Share on other sites

as per what Wetkit says:   just put a bypass box in place between supply and inverter then you can say you are " off grid"  i have only had two installs where clients have applied for Net metering with COCT, it is a nightmare and then you have to pay R400 per month for the privilege of sending your surplus back to the grid. The imeon can run without batteries but you have to manually start it and if a power outage occurs when you out..hmmm, my system has only a 500ah battery bank, overnight it does not use more than 30 - 35%, batteries are always at approx 52vdc in the a.m. a std system as wetkit said with 10 x 300wpv and balance of system would cost around R115k installed.

My Bypass Box.jpg

Link to comment
Share on other sites

On 2016/02/24 at 9:13 AM, The Terrible Triplett said:

And what if one has an off-grid installation, system nowhere connected to the grid, separate circuits, does one still need to apply for permission?

I've always wondered about that, what if you do grid-fallback (as you and I do) at night, but your system is essentially a solar UPS... makes no sense that you have to register then. I'm assuming that what they are after is people with GTIs and grid limiters, though the definition is definitely broad enough that it makes you worry.

Link to comment
Share on other sites

Where would they classify the Voltronic range when you have panels connected to them and inverter connected to your DB?

 

EDIT:  

Wetkit said: If you get your bill from City of Cape Town and have a Solar PV connected to the grid, you need to register.

Best way to get around this is to have your system off-grid by having a change-over switch to switch between solar and grid power.

It reminded me again why I was so insistent back then to have mine completely separate.

Link to comment
Share on other sites

According to the City of Cape Town, ANY solar device using direct Eskom power needs to be registred.

It is from there that installers install the change over switch to get past the problem. So now you can run either solar or eskom.

You are not allowed to have the inverter connected directly to eskom power, even if the inverter cannot feed any power back.

 

I have asked the council about UPS's, but the answer is the same, as soon as the UPS have solar back-up, you need to have it registered :(

Link to comment
Share on other sites

About 2 years ago a person at a government department said the way they catch people who are building without plans (new and extensions) is to compare aerial photos from few weeks/months back to latest ones taken. Working quite satisfactorily, she said, after having fined a number of owners that year.

A thought then passed through my mind, fleetingly, a split second burst ... I wonder when they will start to looking for solar panel installations, comparing it to approved installations?

Link to comment
Share on other sites

1 hour ago, The Terrible Triplett said:

I would have used a automated method. :D

for what reason would you want an auto changeover?  primary is on Eskom and solar on secondary. if you have sufficient solar / battery you never need to switch over, or unless you have a heavy load suddenly. But by the way, for the folks with true hybrid systems, legally you can have a 220vac supply to them, as long as in an outage there is galvanic isolation.

Link to comment
Share on other sites

That is ideal to run 24/7 off solar.

But not everyone may have the panels and batts matching their load for that period of time, because for these smaller systems Eskom is definitely a cheaper alternative than more panels and batteries.

So I thought that your picture, have the system switch from solar to Eskom (at night) and back (mornings), automatically, based on SOC of the batteries, using a BMV.

Link to comment
Share on other sites

1 hour ago, The Terrible Triplett said:

That is ideal to run 24/7 off solar.

But not everyone may have the panels and batts matching their load for that period of time, because for these smaller systems Eskom is definitely a cheaper alternative than more panels and batteries.

So I thought that your picture, have the system switch from solar to Eskom (at night) and back (mornings), automatically, based on SOC of the batteries, using a BMV.

that makes perfect sense, why did I not think of that.......my bad

Link to comment
Share on other sites

I did not want to spend the money on batteries. It will take us through a 3 - 6 hour loadshed and it runs us at night from 11pm. That is why I build AICC to manage it all for me. If batteries get better / cheaper I may go totally off grid but I did a calculation and it is not worth it to buy batteries now. Eskom is still cheaper. So now I have best of both worlds and it did not cost me R300k like some other companies quoted me to do what I am doing now.

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...