Solar PV Monitoring/Automation Thread

jasgrif11

Given my meter box is also on my garage could I install the changeover switch inside that using the mains tails and then Into the smart meter?

I guess the inverter would need to be isolated as I would essentially be feeding its own power back into it.

irishchris

https://www.boards.ie/discussion/comment/121431200#Comment_121431200

Totally recommend getting a changeover switch.

Got mine installed last year for €50 but had purchased the hager switch myself for €45 and a small sub consumer unit for €15.

Fitted the changeover switch in that with main grid feed from meter box to one and backup swa cable to the other entry of the switch. Single cable then from that sub board to the main incoming 63a of the main consumer unit.

SD_DRACULA

On the topic of changeover switches, I assume you just wire from the backup port of the inverter to the CU right?

Oh and what cable diameter would you need for about a 30 meter run to not have (much) loses? 10mm2? More?

micks_address

https://www.boards.ie/discussion/comment/121431746#Comment_121431746

ive just run one circuit from the EPS output on my inverter. It runs the broadband (satelite), tv and will run some lights and boil a low wattage kettle/coffee machine for emergencies.. electrician wired it for me with a separate rcbo on the circuit.. is always on so handy

SD_DRACULA

I noticed that when I set the batteries to charge to 100% at night it misses it by about 5%

Anyone know which of the variables I need to adjust to fix that?

    charge_voltage: 53
    charge_hours: 9
    night_usage_wh: 3500
    battery_capacity_wh: 20480
    lower_soc_limit: 15
    now_soc: '{{ states(''sensor.battery_state_of_charge'') }}'
    target_soc: '{{ states(''input_number.grid_charge_to_soc'') }}'
    soc_to_wh: '{{ (battery_capacity_wh / 100) | int }}'
    now_battery_usable_wh: '{{ ((now_soc - lower_soc_limit) * soc_to_wh) | int }}'
    target_battery_usable_wh: '{{ ((target_soc - lower_soc_limit) * soc_to_wh )| int }}'
    charge_needed_wh: '{{ target_battery_usable_wh - (now_battery_usable_wh) }}'
    current_needed_a: '{{ ((charge_needed_wh/charge_hours) / charge_voltage) }}'

I could just add more to current_needed_a but I rather get the calculation correct instead.

HotSwap

https://www.boards.ie/discussion/comment/121431746#Comment_121431746

Is it manual? Can you describe how it works?

JayBee66

https://www.boards.ie/discussion/comment/121449211#Comment_121449211

If you Google a "generator changeover switch" then you'll see what they look like.

There's more than one way of wiring them so mine requires an additional circuit breaker. The switch has three positions; grid, off-grid and neither, which is in the middle and gives the inverter time to realise the grid has been switched off or on. In grid mode the inverter behaves as it should and in off-grid mode the Emergency Power Supply is switched in. In our case I believe the Earth and Neutral are common to both (a quirk of the way ours was wired). Only the grid and off-grid Live wires are switched.

When there is a power cut, the inverter recognises the loss of grid supply but you have to physically switch to off-grid so that the grid Live is disconnected and the separate off-grid Live is switched in. Otherwise, the house remains unpowered and the off-grid circuit is not connected to the grid thus protecting engineers from shock. As was the case, earlier in the week, when the ESB was replacing a few poles. The neighbours went into the village for a takeaway. I cooked a meal and watched YouTube.

Tree

I've a Huawei backup box, again, was in the order of 750€ installed in '21. Totally automatic, islands the solar and powers any circuits wired to it (fridge side of the kitchen, living room where the modem is), allows the full solar and battery to be used. Failover takes less than a minute in both directions.

HotSwap

https://www.boards.ie/discussion/comment/121450392#Comment_121450392

Your inverter is a grid tied inverter though right? And it sounds like it has a built in “emergency power” output?

So you are essentially using the inverters backup power output in place of the grid to make the inverter believe that there is a grid connection when in fact there isn’t? Am I right?

This also energises your projoy auto DC isolation switch? Which is how you can use your panels?

what happens if your panels are producing 2kwh and your only using 1kwh in your house when this switch is in “backup” mode?

graememk

https://www.boards.ie/discussion/comment/121451171#Comment_121451171

PV inverters can match demand from solar. Although only systems with batteries can provide backup power.

If batteries are full, and sun is shining and only 500w is being used, the solar will only produce 500w. Solar power doesnt have to "go" anywhere, it just isnt generated.

HotSwap

https://www.boards.ie/discussion/comment/121451233#Comment_121451233

I know; that’s exactly how mine is setup. But this inverter thinks it has the grid available to it (ant least that’s what it sounds like) And by the sound of if still has a N and PE connection to the grid. I want to know what happens in this users setup.

JayBee66

https://www.boards.ie/discussion/comment/121451171#Comment_121451171

Grid-tied with emergency power, yes.

The inverter detects grid loss and switches to emergency mode. This permits the inverter to continue working. I think regulations say that it can't power the house until the grid is disconnected, hence a changeover switch.

On power loss the DC isolation switch goes open after a number of seconds. Generally, I wouldn't be able to get to the grid/off-grid changeover switch in time so that will disconnect. I'm on number three as far as that switch is concerned. When this one fails from too many switchings I won't be replacing it.

In emergency mode there is no grid to off-load excess power so the excess is lost. The inverter takes only what it needs, in that situation. Excess power goes to the battery, if there is capacity, otherwise it is lost until there is a grid connection.

HotSwap

https://www.boards.ie/discussion/comment/121451401#Comment_121451401

But after you activate your transfer switch; and connect the emergency output of the inverter as the main input of your home (in place of grid); does the inverter not at this point think it’s connected to the grid again?

JayBee66

Ignore. Solved.

JayBee66

https://www.boards.ie/discussion/comment/121451434#Comment_121451434

No. It goes into a different mode, as shown on the panel. There are three lights; grid, off-grid and fail. Also, the menu screen shows a different mode. The inverter knows there is no grid because it is not getting power. Instead, it has to power itself with the battery.

I suppose on a philosophical level you could argue that the inverter is not aware but on the programming level the creators of the inverter treat grid-loss differently.

irishchris

https://www.boards.ie/discussion/comment/121451434#Comment_121451434

You should always disconnect the ac to the inverter so it isn't fed it's own backup power or will keep increasing voltage. Simple turn off of the ac switch before turning on the generator switch

HotSwap

https://www.boards.ie/discussion/comment/121451440#Comment_121451440

Got it. I think I’m making an incorrect assumption about the location where you have installed your transfer switch. I was thinking you had installed it between the meter and your consumer unit.

but by what you are saying it is between your consumer unit and your inverter? Is that right?

HotSwap

https://www.boards.ie/discussion/comment/121451445#Comment_121451445

Yeah. But that’s not what this guy is saying. I want to understand his setup.

JayBee66

https://www.boards.ie/discussion/comment/121451459#Comment_121451459

Yes. That is correct. Transfer between consumer unit and inverter. The inverter (KStar BluE-S 5000D) is specifically designed for this.

I believe there are other inverters where this doesn't happen, hence people worrying about the inverter consuming itself and becoming a perpetual motion machine.

HotSwap

https://www.boards.ie/discussion/comment/121451479#Comment_121451479

And how do you prevent this from feeding back into the grid?

JayBee66

https://www.boards.ie/discussion/comment/121451510#Comment_121451510

That's what the transfer switch does. The consumer unit is not connected to the grid. It's connected to the inverter via the transfer switch. The inverter is connected to the grid. The transfer switch determines whether you are using hybrid electricity (grid on) or battery (grid off).

In hybrid mode the inverter is "blending" grid and PV. In emergency mode it's battery or nothing.

The house is no longer connected to the grid. The inverter is. When there is grid loss, I hear "relays" (or whatever) disconnecting and others reconnecting. The inverter goes into emergency mode and the house is no longer physically connected to the grid.

jasgrif11

I am looking for some assistance with Grafana querying via HA.

I'm trying to plot a 7-day moving average for my Mains Electricity. If I change "Group BY" to time(1d), I don't see anything on the graph. What am I missing?

micks_address

Hi folks,

I'm wiring a electric towel rail to tank 2 on the Eddi..I've home assistant and Google home. Is there a way I can set it up to respond to he Google turn on the towel rail... Looks like there's no direct myenergi and Google home integration? I've home assistant myenergi integrated set up and working ok.

Ha Long Bay

https://www.boards.ie/discussion/comment/121453804#Comment_121453804

Do you have Home Assistant linked to your Google account (Settings -> Voice assistant) ?

If so you could create a script in HA and then setup a routine in Google Home. In Google Home it should show up when you select Add scenes.

More information here.

https://community.home-assistant.io/t/running-ha-scripts-from-google-assistant/278392

riccol1966

https://www.boards.ie/discussion/comment/121450392#Comment_121450392

I thought all changeover switches had to be double pole, i.e. switching N and L? I've got one of these for use with a genny on a few circuits- the sparky placed a new CU beside my existing one, added a double pole CO switch below, and moved some circuits from the main CU to the new one. Then in a power cut, I switch from Grid to nothing (break connection) to Off Grid (genny). So if you don't double isolate isn't there a danger that power could be fed back to the grid Neutral if there was a fault on the off grid circuits? At the genny end, the plug is Neutral-Earth bonded to create a 220V on Live, and then I run a cable to an earth rod from the genny chassis so that L,N & PE are all isolated from the grid. At least that's what I thought way the correct way, perhaps I'm mistaken?

FWIW I'm getting my inverter for my new panels next week and I'm wondering if I should ditch the genny and use the CO switch for the inverter off-grid .. but then I'm wondering what about the shared earth connection between inverter and grid. Mmmm....

JayBee66

https://www.boards.ie/discussion/comment/121453949#Comment_121453949

Now I understand why they put a breaker on the changeover and insisted that I switch it to the off position when off-grid. It must be to stop feed back to the grid neutral. My installer stopped using that method to wire in my changeover switch and was going to change it to a "new way". However, I was so tired of them not solving a problem involving excessive grid usage (and no battery usage) overnight that when I solved the problem myself (inverter firmware update) I washed my hands of them.

Sometimes, I forget to flip that breaker. I hope I haven't zapped anyone.

ECO_Mental

https://www.boards.ie/discussion/comment/121453641#Comment_121453641

Most of its right although you are selecting power as your unit eg Watts and this goes up and down and not cumulative. You need to select Energy kWh. Then the grouped by unit you have selected is hour, this needs to day if you want to do 7 day average.

All the rest looks grand and are the settings I have

JayBee66

There appears to be a problem for some users of Solarman 1.5.1 on HA. The integration will become disconnected and stay so until HA is reset. The only current solution is for those of us with the problem to roll back to 1.4.3

I have had this problem once a week since installation of 1.5.1

The problem is not inverter dependent as all of us have inverters from different manufacturers.

I have been quoted for a Livoltek system. Any ideas if this is easily integrated with HomeAssistant out of the box or what add on I'd need to buy?

SD_DRACULA

Anyone got some home assistant automation they can share for dumping battery into the grid? I'm working on it myself but might save me some time if others have done it here 😁

Something along the lines of, it gets to midnight (or earlier) and there is 30-40% in the battery, do some calculation and dump all of it but no more than 6kw per hour until 2am and ideally bring it back to 10% at that time for max gains.