Adding PV and Battery System to existing fits PV install - DNO involvement.

[martinW]

Hello All,

I currently have a 3kw PV install for which I get fits (at high rate). Lucky me....

I am looking to add a battery storage system using Pylontech US2000C or US3000C batteries and a SoFar Solar ME3000SP AC Coupled inverter.

I also want to add more solar panels. I could probably fit 4x 380/400w panels on my flat roof so around 2kw in total (at the moment).

In both cases I will need to get DNO approval, so Would it be better for me (less hassle) to install the Battery system and get DNO approval for that and then install the extra solar panels with a dc charge controller (Victron?) to directly charge the batteries. I believe I don't need the DNO approval/involvement for this as its DC and not exporting to the grid.


Will the SoFar Solar ME3000SP AC work at the same time as a Victron charge controller to charge the batteries?

My thoughts are if I go down the DC solar panels to batteries route, I can add as many panels to my DC system as I want without any need to involve the DNO. I suspect as time goes on I might add more solar panels to increase my charging capacity, although they would probably have to be flat(ish) on the south facing wall...

But Would it work?

thanks

Martin

[Stinsy]

Sounds like a good plan. You’re right on all points so far as I’m concerned.

[Mr Gus]

Sorry to divert the topic (possibly) Martin.

I really think we need a few application for " ... " flow charts, which would invariably help counter lost threads from st elsewhere.

Any possibility from form & function brainiacs (might want to hit up the Martin Lewis website for assistance if you take on this task) ..help out in a different "greening up" way.

E.G. taking on the DNO for "to size, & oversize" renewable projects.

Motivation for others to be sure.

[Moxi]

Martin,

Are you able to run separate off grid ring main for your main loads ? In which case you wouldn't need to inform the DNO at all and you could add batteries and panels to your DC system as you saw "fit" without fear of compromise to your FIT payments.

The nice side to that being that when the lights go out for others in a power cut you (like Nowty) would be sat in the warm glow of your own supply. ie you would have the benefit of both Grid and Off Grid and the ability to swop and change as your needs prescribed choosing when to use the Grid and what to use on the Grid and similarly what to use on your off grid circuits when you have capacity.

Its kinda the way I am leaning in my own plans.

Moxi

[ALAN/ALAN D]

The only problem with on / off grid systems is when there is a power cut the door bell keeps ringing with neighbours asking.
Why are your inside / outside lights still on when no one else in the road has got any on.
The other issue is if you cant sort electrical / electronic problems out your self. Who do you get involved to come and repair faults with out ripping you off. A lot of electrical contractors would have very little understanding of the complexity involved in P.V. / Wind turbine / Water turbine / Power diversion / Battery system looking after / charging / Grid inverters.

[Mr Gus]

Laminated A4 in large print..

"solar Panels & batteries"

[nowty]

The only problem with on / off grid systems is when there is a power cut the door bell keeps ringing with neighbours asking.
Why are your inside / outside lights still on when no one else in the road has got any on.

I know but I LOVE it.



To answer martinW question's, the answer is yes and yes.

Joeboy does that, in fact he has expanded his PV several times and upgraded his Victron charge controller recently. I also do it with some temporary winter panels on my decking area. The two issues are, stats on the ME3000SP won't be correct because it does not know about the power coming from the panels but no big deal. The other issue is the charge controller will throttle back and stop when the batteries are full, so in summer you need to switch stuff on to heat water or charge the EV or something to keep the generation chugging away. But if your happy with just a full battery, job done.

I personally wouldn't go down the OffGrid second system route, been there and its a faff. I do however now have a whole house backup system so Nowty Towers does go OffGrid automatically in a power cut.

[billi]

Hello ,
am Not too familiar with FIT regulations , but for sure a charge controller will work fine next to a AC Inverter charger i guess its probably the fine tuning that is important , of which charge source is maintaining the popper charge regime to avoid conflicts over that question
You mentioned Victron , and they are usually quite competent to deal with those questions , and provide solutions to control relays that can control other ideas like heating etc

Again , without knowing too much about FIT , i assume you are right to just go for the Battery and Inverter approval for your already approved PV ........................... and then do what you like on the DC side via chargecontroller



Billi

[Joeboy]

I retrofitted 2kW inverter to the battery stack. If it goes Peter Tong and i lose mains I flick a switch and plug in. Not as good as having the whole house live of course but it will get us where we need to be for a while during an outage.

[ALAN/ALAN D]

If you are fitting an off grid or grid tie inverter its worth considering where you are going to put it from a noise point of view.
Most of my battery / inverters are in an external brick built boiler house.
I did install a 5K.W. Inverter in the house at one stage with out thinking about the heat sink cooling fans. The fans run at 100% speed / noise even when you are not using any power. As soon as the Lady came home.
It had to be moved to the boiler house. I have also modified the electronics so the fans only run in proportion to the out put power being used to save energy.