Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
What do I need...???
#1
So my layout will be: main bulk of panels will be on garage roof, along with power wall.

Main bulk of my use will be in the house, approx 20m cable length from where power wall will be to where current mains head and consumer unit is.


As yet I have no equipment but in the planning stages, want to make sure my idea will work before I get too deep.


Most likely will set power wall to be 48v (7s) with as many cells as I can get (looking to redo garage and get panels in 2 -3 years and slow going getting cells in UK!)

I want to hook the power wall back into the house, initially taking the lighting rings and my home pc/networking/boiler/house alarm load onto a separate cu powered from PW, with mains as secondary. If I get enough cells to be able to take full plug circuits (TV kitchen appliances etc) then they will also end up the same. At the moment this won't include induction cookers and ovens.

Ideally once wall is fully charged I want excess from panels (if there is any) to go into the emersion heater for hot water tank.

Panels wise my primary ones will be on garage roof, where there is a mixture of shading at various times of year and day. I will then try and get panels on the house but it gets sun on the front in the morning in one corner, and the other opposite corner in the evening so no ideal place to put them.

Question is what equipment should I be looking to get for this? I don't really want to be running 20mm wires to /from garage and house if I can avoid it...
Reply
#2
Fisrt I supose it is a typo, 48V is 14s.

About installation I would do all panels to inverter and powerwall at the garage, and then just a thin cable with AC to the house, no need 20mm2, just 6mm2 for 25A. Hybrid Inverter preferably and enough powerful to feed all the house if these are your plans, even if you don't have yet enough cells or panels but you plan to have them.
Reply
#3
(11-17-2018, 09:51 PM)jesusangel Wrote: Fisrt I supose it is a typo, 48V is 14s.

About installation I would do all panels to inverter and powerwall at the garage, and then just a thin cable with AC to the house, no need 20mm2, just 6mm2 for 25A. Hybrid Inverter preferably and enough powerful to feed all the house if these are your plans, even if you don't have yet enough cells or panels but you plan to have them.

Apologies 14s!

If I feed back 230v AC, then what is controling feeding back to grid(or stopping it!)
Reply
#4
The part of the circuit that you want to power must only hang from the inverter, permanently or temporarily with an ATS (Automatic Transfer Switch).

To avoid the feed back to grid it depends of the inverter too, and the way you connect it and use it, in a offgrid or hybrid inverter in offgrid mode the inverter will feed your house from panels or battery and if not possible from grid, but it will never feed back to grid. With some grid tie inverters you must configure some energy meter to avoid feed back, with hybrid ones is the inverter witch controls all and takes energy from panels, battery, grid or a mix of them and it won't feed the grid if you do not want it.

So first decision is the inverter and how much you want to spend, the more you spend the more possibilities of configurations you have, and will determine if you need more devices to control the feed back.



This is my setup for a hybrid inverter, if something fails on the inverter side or I manually override, the house is only feeded by grid, if not all house is feeded by the inverter taking energy from different sources configured by availability and peak and off-peak grid price.
Reply
#5
Thanks jesusangel, at present I have no inverter but I'd rather pay more and get something I can use long term, then one which I have to replace soon... Looking at your drawing, the inverter would need to sit near my power wall in the garage, so I would need two pairs of wires to feed from grid to inverter and a pair back to the house?
Reply
#6
With my configuration, yes you need to power the inverter from grid too, so 2 pairs of cables, + grounding very important.
Reply
#7
Hi Unclebob,

You are working through the same issues I have had with my set up as your planned system is exactly like mine.

My garage is detached from the house with one mains cable supplying power. Cable is buried under the garden and runs from the house consumer unit to the garage consumer unit. Total run for this cable is over 20m. It is buried under the lawn, walls, paths, patio etc. It will be a total nightmare to add another cable so I'm not doing that.

I want to run my house lighting and certain circuits (sockets) from self generation.

What I have done so far:
-Installed 8 panels on the garage roof.
-Installed a PIP4048MS (Voltacon version) in the garage.
-Built a 10kw powerwall. 14S80P.
-I disconnected the incoming grid power from the garage and connected the inverter output. The garage is now offgrid.

What I have now been trying for several months to do is find an electrician that is prepared to 1) replace my house consumer unit and 2) install a parallel CU that contains transfer switches so I can flip between grid and solar for the various circuits. (I too will not be using solar to power my range cooker nor my 9kw electric shower. I will use solar for an immersion heater though).
So far, all electricians have declined to even come view my house in order to give me a quote. Some of them held a lengthy conversation with me and concluded that what I want to do is highly unusual and they have never done it before. They confirm that its not illegal or anything, but they have never installed transfer switches like this.
So either i'm just having rotten luck with this or this is truly going to be a sticking point for many of us trying to create this type of setup. I am starting to think that the only way I can get this done is to register the works with the council buildings control and do it myself and get a certificate from the council. This may actually end up cheaper, even with the fees, but i'm not an electrician. I'd rather an electrician do it!

Anyway, assuming I solve that particular hurdle, I'l still be left with the issue of having a single cable running from the garage. My solution here is to have the garage as a producer only. Never a power consumer. The way I'll do this is to always keep enough power reserve in the batteries to power the low requirements of the garage for 3 or 4 days operations with no sunlight. This should be enough to outlast bad weather etc even in winter. To achieve this, i'll simply switch the house circuits back to grid during long spells of bad weather and low battery voltage.

It will be quite a manual system, but i'm ok with that. In fact, i prefer it. I find this micromanagement fun (for some reason!)

So that's where I am with my system. What I will say about yours, is simply to not underestimate the impact shading will have. Assuming you install your panels in pairs, for about 60V (like I have) even if just one cell of one of the pairs is shaded it will reduce output of that pair to almost nothing. Bear that in mind when working out expected output.

David
Reply
#8
Thanks for the info David, I've done my city and guilds in electrical installation, so fairly confident into the ac side and may go down the self cert via building control route as you suggested, it's the DC side I'm unsure of! So if I get a hybrid inverter in garage, it will charge batteries and put electronic directly to output, if no panel input it will draw from batteries. If Barrie's depletion, the. Will push mains feed in, back out. All good on that side. But I guess that doesn't allow and excess solar input (batteries fully charged and no draw from house) to be dumped into my dhw tank via immersion heater... In the above, the immersion would be wired and will come on as per timer and thermostat?

Is there such a thing as an inverter with excess dump?

At present I have no cabling running so am free to run what I need...
Reply
#9
(11-19-2018, 07:28 AM)unclebob Wrote: Thanks for the info David, I've done my city and guilds in electrical installation, so fairly confident into the ac side and may go down the self cert via building control route as you suggested, it's the DC side I'm unsure of!  So if I get a hybrid inverter in garage, it will charge batteries and put electronic directly to output, if no panel input it will draw from batteries. If Barrie's depletion, the. Will push mains feed in, back out. All good on that side. But I guess that doesn't allow and excess solar input (batteries fully charged and no draw from house) to be dumped into my dhw tank via immersion heater... In the above, the immersion would be wired and will come on as per timer and thermostat?

Is there such a thing as an inverter with excess dump?

At present I have no cabling running so am free to run what I need...

I'm using a SOLiC 200, to power an immersion from my surplus energy rather than dumping back to the grid prior to getting my powerwall batteries set up.
Works very well and since it's supplied from my normal consumer unit it's after the generation meter there's no loss in FIT.

UK Southwest.

7 kWp Solar Panels (28 x 250Wp Shinetime Mono).
14 X APS YC500i Micro Inverters.
28 X 40P 18650 cell packs/modules configured as 14S 80P.
Sofar Mass Energy ME3000SP AC coupled charger/inverter.
Still sourcing and processing cells for powerwall.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)