Solar along with the grid to supply AC loads

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tighernan asked Jan 18, '23

Solar along with the grid to supply AC loads

Is it possible that PV can run the AC loads or at least contribute to the grid supply. Today for example, plenty of sunshine and a full battery. the PV chargers only letting through 5w, while its taken average 200w to run the AC loads. An ideal scenario would possibly be. Solar tops off the batteries first thing in the morning, then between solar and battery storage the AC is run for the day, Only using the grid in the evening's to help with the short fall of power. Is this looking for to much from the system ? We are using two MPPT, 250/100, 150/35 along with two multis.Screenshot_20230118_140414_Chrome.jpg

system design smart solar charging behaviour balanced ac-load

screenshot-20230118-140414-chrome.jpg (296.8 KiB)

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Alexandra ♦ commented · Jan 18, 2023 at 08:00 PM

@Tighernan

Are in a mobile setup or fixed at a house?

The easiest way is to switch it to inverter only in the device inverter menu.

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kevgermany ♦♦ commented · Jan 18, 2023 at 07:26 PM

Are the multiplus pair in on state or charger state?

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tighernan kevgermany ♦♦ commented · Jan 18, 2023 at 08:27 PM

Hi, the pair of multiplus are set to on. While working out the kinks, I thought this was the best choice, especially seen as somewhere along the setup we have an issue where our volts are not corresponding to our battery presentage.

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tighernan answered · Jan 19, 2023 at 09:15 AM

Hi John,

A very clear reply thank you, and now you have given me a path to follow.

Yes the goal is to me as much off grid as possible, not only for the electrical cost savings but also as an experiment to see what we can achieve so as others might learn from what we are doing.

In Ireland its nothing but solar companies pushing solar, with sales people almost reading from a script. When the system is installed the people soon come to realise the short fall in what has been installed, at that stage its to late.

Last night was a clear example. There was a power outage in our area, which for us is not a common thing. Some of our friends and neighbours have solar installed, off the shelf company installed system's. Our house was the only house with the lights on using the Victron system we have installed.

We purposely installed our system in a place people can come and see it working, and ask questions. This way of self installing is not for everyone. In saying that everyone looking at solar as a way forward can learn, and better equips them with questions for when the solar companies come calling.

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Modifications Space

Node Red Space

Answer 1 · 2023-01-19T06:56:20Z

JohnC answered · Jan 19, 2023 at 06:56 AM

Hi @Tighernan

In this situation it's best to leave a little room in the batteries so that the solar can still run at full tilt. Grid supply can't be 'dribbled' in to ac loads to supplement inverter power. There's options to consider though..

An offgridder can automate switching in a genset when it's required. In a similar way, grid can be switched in as needed. But instead of sending a signal to a genset, you switch in the grid. Given that the Multis have the ACin relay on board, it's convenient to use Multi Assistants to do this.

Another way might be to heavily limit grid input. There's a lower limit that applies, and this might get a little mushy to operate.

Also Multi charge can be limited. Either via Amps or reducing the target charge V. Trouble with some of these things is that the grid still takes ac load priority over inverter. So best to force it off altogether IMO.

I'd imagine your ultimate aim is to maximize solar power. Using your batteries is the most effective way to do that.

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tighernan commented · Apr 19, 2023 at 09:30 AM

@johnc. Apologies for barging in like this, Is it possible to contact you and ask you a direct question regarding, ESS, DVCC and feeding back to the grid?

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JohnC ♦ tighernan commented · Apr 19, 2023 at 10:58 AM

@Tighernan

ESS isn't my go, so best to expand upon your needs or ask a fresh question so those experienced with it can help. For some reason I thought your issues were non-ESS, but indeed that's another option.

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tighernan JohnC ♦ commented · Apr 19, 2023 at 11:03 AM

My question is indeed separate from this thread. I just used it as a link to contact yourself. Thanks for the speedy reply.

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