Inverter and Battery Location

[Johnnyt]

Hi all,

 

I intend to fit integrated PV on the front elevation and on the westerly elevation of the garage, see site plan attached.

Currently favouring Solar Edge although I have Enphase currently at home which has been faultless in 5 years.

Given the proximity of the garage to the main house which is the one on the RHS of the plan, is it favourable in terms of space in the utility to locate the inverter and battery in the garage?

Mains electricity will come in at the rear of the site rather than from the road, so i thought the mains could initially feed the garage then an armoured supply to the main dwelling with associated consumer unit et al.

I hope the overall PV system to be circa 10Kw and have had an initial response from the DNO that this could be accommodated without transformer upgrade.

The garage is less than 5 m from the main house.

Any thoughts good or bad would be greatly appreciated.

 

Thanks

20_01146_S73-PROPOSED_SITE_PLAN-3718478-4.pdf

[ProDave]

I can't see a problem with that, the garage would be a good place for both.  My panels are about 30 metres away from the inverter with no problem.  Include a good sizes separate cable duct from the house to the garage for all the PV cables.

 

If you want a solar PV diverter to put excess power into the water tank you would need one with a wireless sensor connection, several are available.

[Pete]

My garage is approx 15 metres from the house and in the future may put PV on the garage roof. I am about to put in my SWA (6mm) for the power to the garage, do I need to put anything else in to enable me to install PV or is the SWA sufficient? I would want the inverter etc in the garage, mains supply comes into the house and then to the garage via the 6mm SWA.TIA

[PeterW]

For the difference in cost (~£1/m) I would upgrade to 10mm anyway as it is easier to do now than in the future. 

[Pete]

5 minutes ago, PeterW said:

For the difference in cost (~£1/m) I would upgrade to 10mm anyway as it is easier to do now than in the future. 

Already bought the cable! Have read Prodave message again and understand what he means by extra cable duct if inverter in separate building to PV panels. I will only be putting up about a 4kw array and most people on here have used 6mm and it all works fine. I just need to know that all I need to put in place is a 6mm cable and nothing else. Thanks

[Jeremy Harris]

6mm² is fine.  Voltage drop is the main criterion, and for 15m of 6mm² SWA the voltage drop at 4 kW is less than 1%, so well inside the acceptable limit.

[Pete]

2 hours ago, Jeremy Harris said:

6mm² is fine.  Voltage drop is the main criterion, and for 15m of 6mm² SWA the voltage drop at 4 kW is less than 1%, so well inside the acceptable limit.

Thanks Jeremy, so just to confirm I only need my SWA and nothing else from house to garage to be able to put PV in the future on the garage roof? TIA

[Jeremy Harris]

53 minutes ago, Pete said:

Thanks Jeremy, so just to confirm I only need my SWA and nothing else from house to garage to be able to put PV in the future on the garage roof? TIA

 

 

Yes, that's fine, no problem at all, just a single run is all that's needed.  You could go up to about  9 kW on 6mm² over 15m.

[Johnnyt]

Thanks for your suggestions.

I've read that running data cable from the garage to the dwelling may be a good idea as well to enable communication with immersion diversion and any other dedicated outlets.

 

 

[Jeremy Harris]

Running Ethernet cable might be handy, but it will need to be in a separate duct, with at least 100mm (I think) separation from the mains cable.  AC coupled battery systems often need to sense both the power generated from a PV system and the power being imported and exported at the meter tails, and will often use Ethernet cable for the current transformer signals.    There are some immersion diverter systems around that have a wireless connection between the sensor at the meter tails and the control box.  The Apollo Gem is one that I know has a fairly good wireless range, for example.

[Pete]

One more question, if I have PV panels on my garage (detached) roof and the inverter inside the garage how does the mains board know if the electricity supply is coming from my PV or national grid? Mains supply comes into the house and garage fed from their. TIA

[SteamyTea]

It is to do with voltage.  The inverter will supply at slightly higher voltage than the grid.

Then, because nature hates things being unbalanced, the electrons go looking for a load to reduce there energy state.  The first load they find will do, if it is big enough.

This is one reason that voltage drop is important.  You don't want your cables heating up.

 

[ProDave]

I suggested a spare duct "just in case"  It is trivial to install one at build time, a HUGE job if you find you need one later.

 

In my case the electricity meter is remote and when you come to fitting a solar PV diverter, you need a connection from the meter to the solar PV diverter.  I used a wired connection using a length of 6 pair armoured BT phone cable (just because I had it)  but you can also now buy solar PV diverters that uses a wireless connection.

 

But I would still install a spare duct just in case because it is so easy and cheap to do at build time.