There doent "need" to be a voltage rise to the inverter, its just inherent in electric circuits.

UK supply voltage is nominally 230vac with a tolerance of +10% and -6% so up to 253vac is allowable. Our house voltage is 250vac with no load. When your inverter is pushing 16amps down 30meters of cable there will be some resistance with any size cable and that resistance will vary depending on the cable size/length. When the inverter is trying to push 16amps to the consumer unit it has to increase the voltage slightly to make the 16amps flow. If the resistance of the cable is high because the cable is too small/long, the voltage will have to rise more to get the 16amps to flow. If the cable resistance is lower because its a large/shorter cable the voltage wont have rise much to overcome what is a smaller resistance.

If you start with a high house voltage such as 250vac and youve got a 2.7vac rise then that will push the voltage at the inverter to 252.7, just shy of the UK limit. Now its only the inverter that is seeing that voltage because the other end of the cable is at house voltage of 250vac so the house remains within limits but the inverter is pretty close to the limit. Whether thats a problem for you or your spark is up to you. The inverter and any reputable cable/isolator will be rated for way beyond normal mains voltage so no problem there. There may be more issues though.

If your not using any PV when youre generating at the 16amp limit that 16amps has to find its way into the grid. If your grid connection is poor, like ours, not only will the inverter voltage rise above the house voltage, the house voltage will rise above the grid voltage. In this situation you could see the house rise to the UK limit with the inverter a few volts over, or whole lot go over the limit. With a G98 16amp limited inverter I beleive the DNO is obliged to modify the grid to keep the supply below the 253vac limit. With just one of our systems running our house voltage is well over 253vac so the DNO is upgrading our transformer FOC.

Ignore the 262vac as thats under abnormal conditions if something in the design has gone seriously wrong

Ideally if you can is run as much of your distance as DC to the inverter as this will be at higher voltage 400V plus and therefore can carry greater current so smaller gauge cable then leaving a minimum amount from you inverter as AC 230V. If your distances are not large then it probably matters not but it gives a leeway in sizing the cables

Posted By: neelpeelI don't really have space for the inverter in the house so I guess I either need some hefty cable (and get the sparky to do some calcs) or I need to build a mini 'lean-to' unit to house some electronics on the end of the house.

The inverters we get here can be mounted on an outside wall without additional protection and I suspect yours will be the same so a mini 'lean-to' unit should not be needed.

Neelpeel , I think what would be needed is some kind of oversized cross shaped capping to link horizantal and vertical bars.
ive no idea if anyone makes it. Ill have a search.
You could just use the GSW trays without felt as they have a central access hole.

Thank James. It just doesn't seem that there is an easy solution out there and I could see myself chasing leaks for the next 20 years...so I've decided to stick on some steel box profile. Should last the duration.

Posted By: cjard@renewablejohn is a leaf 3 phase? I thought they were 1ph

The leaf is just a battery with the old ones being 24kwh and the newer ones 40kwh. The 3 phase I believe is down to the inverter but if you wanted you can break down the 24 kwh battery into 3 x 8kwh batteries and there is a video on you tube of an Australian company which provides the cabling and battery management system capable of doing this.

I am a total rookie trying to sort out a system to use these bifacial solar panels. I know what I want to end up with but totally confused on how to achieve it.
To date the only thing I have achieved is the method of mounting the bifacial panels vertically in 2 rows with a tilt mechanism to turn them horizontally for a crude form of tracking.
I can see the advantage of battery storage but cannot justify the cost unless I use an EV like a Leaf and a V2H system. But then I also want 3 phase to charge the leaf direct from the solar.

<blockquote><cite>Posted By: philedge</cite><blockquote><cite>Posted By: renewablejohn</cite>
I am a total rookie trying to sort out a system to use these bifacial solar panels. I know what I want to end up with but totally confused on how to achieve it.
</blockquote>
I know nothing of V2H but a quick internet read suggests its in early developement stages with limited trials going on. Because its V2House and most UK houses are single phase supply, I think youll be waiting along time to integrate 3 phase into V2H. Single phase bidirectional chargers seem in limited supply so I guess 3 phase ones are even more limited if they even exist outside of a developement lab.

Maybe speak to one of the trial operators or install a 3 phase system but forget the V2H for now??</blockquote>



This is the sort of system I have been looking at.

https://voltaconsolar.com/grid-tie-with-energy-storage-systems/voltasol-on-grid-self-consumption/voltasol-hybrid-inverter-10kw-pylontech-lithium-battery.html?utm_medium=cpc&utm_source=google&gclid=CjwKCAjwqauVBhBGEiwAXOepka1rVvlDsSvEAQzEcGyDuPzAqGl3tAsphAKvAzfelNHBa6_6cD0OUhoCJCAQAvD_BwE

Which will then enable me to run the house and fast charge the leaf battery using 3 phase. Just dont know as yet how the V2H links in from the leaf battery back into the existing energy storage system.

Posted By: philedgeThe inverter you linked to seems a standardish inverter/battery combo.

If you google "V2H charger" you could ask the handful of manufacturers to explain how the bidirectional chargers work and would integrate with a 3ph system

Looks like the choice is a wallbox quaser but limited to a leaf or mitsubishi or wait for the quaser 2 for the majority of cars. Both appear to allow fast 3 phase charging as well as use of the vehicle battery to supplement a small household battery.

Posted By: revorHave you costed a 3 P charger? I have 3 P but was told the cost of and installation would be several £k though did not get a proper quote. It would be 22Kw charging. A DC charger you are in the £20K region which is the only way to get fast charging. Few vehicles as I understand will have an on board 22Kw charger and are likely to be the more costly EV's.
I too would be interested in V2H but think we are way from that just yet. Will EV manufacturers be happy to warranty the battery if used this way?

Posted By: renewablejohnallow fast 3 phase charging

What do you mean by this staement?

The prices your quoting seem way out. I am looking at 3k for a hybrid 15kw 3 phase 48 volt system and another 2k for a starter battery pack. (main battery looking at a leaf 24kwh).

The fast 3 phase charging refers to the function of the Quaser not being restricted into using single phase but able to use 11kw 3 phase to significantly reduce charging times like a fast charger. Have a look at the Quaser specs and the upgraded Quaser 2 specs. Think the Quaser is 5k but my thought is that I could easily spend that on batteries and still not have the capacity of a leaf battery. The leaf battery holds approx 3 days of my normal household usage.

Looks like I got it wrong the wallbox quaser you can discharge as part of the V2H but the 3 phase charging is the wallbox pulsar plus being upto 22kw

https://wallbox.com/en_uk/wallbox-pulsar

The electric input quoted above.

Also found Anderson EV 3 phase charging which links into 3 phase solar charging but looks like it is a minefield as to what cars can actually accept 11kw or 22kw fast charging.

So, I sent a spec to a handful of local MCS certified sparks last week to get an idea of costs and timescales. Only 3 have came back to me and all 3 have stated that they have +6 months work booked up and are not taking on jobs.
Looks like I'm heading down the DIY route then.
Frame is mostly up and box section steel is 3-4 week delivery so some time to play with.

I was surprised to receive a call from SSEN today in response to a query a lodged a few weeks ago...I was asking if I can install higher than the 3.68kW limit, install a 5 or 6kW inverter (to give future upgradeability), but set it to cap at 3.68kW in the software. I saw this on a forum as a known solution. Apparently though the inverter MUST be 3.68kW rated or less and a software setting is not allowed.
Now considering if it's worth going down the G99 route now so that I have dispensation for greater than 3.68kW in the future (I can see myself wanting to upgrade later).

Most inverters export limit (AFAIK) is now set via software accessible via engineers password. I guess if you are doing to your own install you should get the password with the inverter, you will need it to access other functions anyway. As an user you are not supposed to be able to have access to the password but you should be able to get it. If stuck you can ask on some electrician forums if anyone knows the PW for the particular make. Perhaps your choice of inverter could include PW availability.

I am having a similar problem on getting a system installed. As a solution I am looking at a hybrid system with batteries but it seems far easier to install as a non grid tie system. Is there any reason why the Grid tie could not be done later when the sparkies are not so busy.

Hi,

I may have missed something critical above, but that's a bit of a sweeping statement IMHO.

Off-grid systems, depending on intended use ... almost always must have storage to aid regulation if nothing else, will usually have parts running at much lower voltage and higher current (my entire off-grid system runs a a nominal 12V), may have a dump-load to make use of power in the absense of the effective infinite sink that the grid provides and must have one for sources such as wind, the inverter is often also a controller to manage the storage, etc, etc.

Rgds

Damon