Feature request / Help: using excess solar power no feed-in

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misullivan asked Oct 12, '19

Feature request / Help: using excess solar power no feed-in

Hi All,

I seem to be unable to configure what I was told the EasySolar could do. It’s possibly my fault, but if not it’ll be a feature request that I think would potentially sell a lot more victron units in Australia.

If one selects “grid code” of “none” it seems I cannot use PV power unless in powerassist mode, UPS (in Ac-in fail) or batteries need charging mode. Ie under normal operation (grid/generator present) PV power will reduce as the batteries charge, and even though I have 1.6kw of panels I’ll see charging of just 20w etc.

ESS cannot be started with a grid code of “none”

ESS cannot be started using the Australian grid code (it warns that a secondary relay is not present in the product)

Selecting UK (and others) will allow the ESS to start and one can then select “use excess PV power to feed into the grid” which then will use all PV power available (Which majority of the time is lower than the load).. but obviously this would be non compliant (and therefore illegal) if running without an anti-islanding relay.

I have also noticed I have to set “keep batteries 100% charged” for it to work, using “optimized” will cycle the batteries.

Setting “power assist” will work sort of... if I set the limit input to 4.5A it will use a couple of hundred watts to power the load, however it will never use less than 700w no matter if I set the input limit to 0.5A... (it just sets itself back to 4.5 in the GX) ... and worse (for my situation) should the load go over the available PV power it’ll discharge the batteries.

So nothing does what I want to do.

I want to use the easy solar as a UPS and have the PV power reduce grid power. Ie:

I have “cranker batteries” (24v 200Ah flooded flat lead plate) so they should be just used when there is a grid failure. Grid is stable for most of the year but I have a lot of computers hence needing/wanting to use “UPS” mode. I do not want to feed any power into the grid,.. just downstream to the loads. If there is excess PV power after the batteries are charge and the grid consumption hits zero just reduce the output of the MTTP charger. (This is got local regulations compliance... domestic premesies are not allowed to feed in more than 6kw of power.. which I wouldn’t anyhow, but as a consequence no installer will install greater than 6kw without an upstream limiter and non seem to want to do Victron stuff.. so I’m installing them (EasySolars) as UPSs for each power rail in my mini DC.. i’ll End up with >6 of them and 18kw of panels if they can actually do the job I need.)

Thoughts/direction welcome.

EasySolar All-in-One VEConfigure 3 ups

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Answer 1 · 2019-10-12T06:12:56Z

JohnC answered · Oct 12, 2019 at 06:12 AM

Hi M. Just thoughts..

The 4.5A limit is non-negotiable. That figure is listed for a 3kVA Multi, and will include both loads and charge current. Ac amps of course, so 1000W or more maybe. That will self-limit of course if all load/charge is lower.

Consider dropping ESS, not recommended for installations like marine with just incoming 'shore' power, and that's essentially what you're doing.

UPS usually means fully charged batts, but to workaround, maybe try lowering the Multi charge parameters to (say) 26V flat. That way it will only charge when batts are depleted, and when the mppt is working it will be higher and take natural priority.

The loads of course will continue being served up to that 1000W of shore power, but you could even cut that off with a relay. Like a genny auto start, hey?

Try delving into DVCC, VS and genny autostart to see if you can work something out. You're no longer in real ups territory, more like an offgridder with backup ac and personal preferences.

But your kit, perhaps with an added relay, can do it one way or another. Keep an open mind, and you'll work something out.

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misullivan commented · Oct 12, 2019 at 09:37 AM

Not really what I’m trying to do.

I want fully charged batteries (all the time on standby Incase of power fail)

I want to use all available PV power and if there is not enough, supliment it with ac power... and fall back to supplement it with battery if a/c fails.

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JohnC ♦ misullivan commented · Oct 12, 2019 at 10:33 AM

Yeh ok, I tried to cover that with the '26V' batts minimum. Now that might be + or - that (your choice), but that's a typical long-term storage 'trickle' charge for pb's.

You can't control your ac-in to less than 4.5A. So it's either on or off. Frequent auto-switching under hysteresis effects with small batts isn't good either.

I think I understand what you want. Sort of a reverse form of PowerAssist. Almost akin to bleeding off excess pv power to a dump load.

A holy grail for offgridders.. I hope Victron are the first to invent marketable grails. :)

Sorry I can't help you more..

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