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Hi -
I have an RV and am looking to consume Solar first then the grid or have the Solar off set the grid.
I’ve done research but can’t seem to find clear guidance on how / what needs to be done for my system in order to prioritize Solar over the Grid and would appreciate any help.
My system:
Multi - 3000kva/120v
CCGX
SmartSolar MPPT 100/50
6 - 100w Panels
440A AGM Batteries - 12v
BMV-712
Overall, I want to offset the grid consumption with any available Solar.
Thanks!
Hello. Two years on. I have a similar problem. I have 30 panels and a 48v bank of batteries. Normally, I don't even have the mains connected to my house, as I live in sunny Andalusia. During jan/feb sometimes we have several weeks of cloudy/sunny. For those times I connect to the grid to save the batteries from destroying themselves. Trouble is, I just got a 200 euro electricity bill (one month). This is ridiculous. The sun is out half the time, but the Quattro always gives preference to the grid. For example, currently it is sunny and there is at least 5kW solar power available, but the Quattro is drawing 3kW from the grid! Nothing from the solar array! Does anybody have any idea how I can fix this? We use 30kW/h per day, so it needs fixing before I go bankrupt. I can upload the Quattro config if anyone wants to see it.
I just thought: If I can't fix this in the Quattro or CCGX, what about a remote control relay at the grid input of the Quattro? At least then I could switch the grid on and off without physically having to go out to the garage to throw the switch. Could use my mobile phone and/or a raspberry pi maybe? Or possibly detect low voltage at the mppts to switch the mains on?
Forgot to mention: this is with batteries at 100%. I could do the trick with lowering the charge voltage of the Quattro, but that wouldn't help right now for instance ie; with batteries at 100%.
Thre are a couple of diferant ways you can achive this, one is by using assistants. as a example on one site I am using the below assistants.
I have not used the below virtual switch option but I cant see why it wont work
you can also use the virtual switch as well to turn the mains off and then run off the inverter
the objective is to never have the battery full, thus you can always store the solar and then use it.
yes it involves a lot of on and off of the ac in relay but it works .
Note I am using it with LIPO batteries and using SOC down to 96 and up to 99 and battery voltage as a fall back.
Or Try also using the Virtual switch
Hi Tabney. Another way might be just to set your multi's charger to a very modest charge programme. How far you go may depend on how you cycle your batts, or even if you cycle them at all. Like you could even set the multi to (say) 12.8V max to prevent batt discharge after dark. Then in daylight the mppt can run it's 'normal' settings and take over. Once that '12.8V' is exceeded under pv charge the multi will back off to zilch.
For me the 'grid' is a genny start/stop switch, usually used after dark in winter for max benefit. But we're all different, and so is how we use our batts.
You could also look into DVCC in the GX, but maybe no real value there for you in the circumstances.
Thanks for the responses. While those may be my only options I was thinking there would be a setting that would automatically decide a lot of this. I assume this will be in assistance and settings.
Since my Solar is only 600 watts I wouldn't want the system to only use Solar when AC loads are less than what the solar output is. I want to us the Solar to off set AC loads to pull less from the grid.
For example, if my AC load is 1500 watts and I'm generating 500 watts of solar I'd want to pull 1000 watts from the grid instead of 1500.
Also, my RV is a Travel Trailer and I do not have a generator hooked up to the system like a motorhome. I have a generator but I'd manually hook it up and turn it on, when needed.
You can try using powerassist. This will work fairly well, but will prioritize GRID over solar, not the perfect solution but with a limit on the ACin, you can set the max it can get from grid, and the rest will come from solar/ battery. This is the reverse of you (and me) want, but without ESS I think is the best we can do at the moment. Not perfect because you need to be fairly sure about the load "W" and the solar "W" availability. I change the ACin limits some times, according to the use I am going to give in the next hours or so.
See my topic here:
https://community.victronenergy.com/questions/14802/using-powerassist.html
In my case I have the AUX in of multi connected to relay 1 of Venus GX so it switches to GRID with Venus command, and then due to the conditions set, it will also use Solar/ battery trough PowerAssist.
This is what ESS normally does, but that would probably not be legal and an anti island protection would be needed.
There is an old HUB1 Assistant mode which is called "prevent feeding energy to the grid". I don't know if this would still make sense in your situation. But you can also use the virtual switch instead.
I think it isn't possible to keep your batterys charged at 100% while prioritize PV as this would need a permanent connection to the grid.
Why is reducing ACin not legal ????
If not running ESS, no need of any islading device, the Multi will never send any power to grid.
Where did you read it wouldn't be legal to reduce ACin?
BTW: I started a feature request for that kind of use.
You can read this for some ideas: what I do is have a switch to select a 'full charge' or partial charge so the solar can do the rest:
https://community.victronenergy.com/questions/8933/example-of-using-assistants-partial-off-grid-boat.html
Thanks again for the additional responses and options.
Why can't ESS be set up on RV (automotive)? What the difference?
Why can't I set it up with ESS and with no Feed In. I do not want to do anything with feeding back to the grid. I just want to consume the solar instead of it not being utilized, I don't understand why this is so difficult for this application.
Because it is not allowed (at least in my region) to have devices that can deliver power back to the grid connected to circuits that are not specifically designed for this.
(due to possible overloading of wiring without the protecting devices knowledge)
Also systems that 'plug in' are not allowed like this.
Technically it is no problem for the Victron system, but ESS systems have to follow the local rules. Ask an electrician if you're not certain about local requirements.
En yes, also if you turn off 'feed back to grid' in ESS it still feeds back a little bit sometimes.
What you want to do is actually very simple, you don't even need a Venus device.
-simplest way is setting charge voltage lower than MPPT's
-little more options: using external switch to select different charge voltages
-also possible: disconnecting grid when batteries are obove xx%SOC
-etc.
Can you please explain what the advantages of lowering the charge voltages are? When the batterys are fully charged and voltages are higher than the multis, what will the unit do? Isn't it switching to float then? I don't get it. As long as the multi doesn't invert I can't see the benefit. But I'm very interested in.
If one is forced to use grid due to unsufficient light to power the loads, then both Multi and MPPT are charging batteries. In a DC coupled system, lowering the voltage of the Multi is a very simple way to prioritize solar over grid for these moments. In this way, the Muti will only provide power to the loads and MPPT will still be of some use because it will slowly charge the batteries with sunpower that would be wasted otherwise, and you save some kWh from grid that were not spent in charging.
Thanks for the replies.
1. If lower the charge voltage on the multi, and the ac loads are greater than the solar output will the solar still be used? Or will the solar only be used when loads are lower than solar output?
2. Any recommendation on what to lower the Multi voltage too? I have Lifelife AGM 12v with a charged voltage of 13.4v
1. The voltage difference is important only if the Multi Charger and MPPT Charger are both ON at same time. And in this condition, MPPT is only charging the battery. If Multi is inverting, you can use solar power directly, but then in this case the voltage difference is completely irrelevant (Multi Charger OFF).
2. I have set in my system the MPPT with +100mV than the Multi charger. You can experiment.
