Solar PV Monitoring/Automation Thread

bullit_dodger · 31-03-2023 11:53am

https://www.boards.ie/discussion/comment/120422339#Comment_120422339

Yeah, I really should do something similar.

50c is still within spec (60C is operating limits) but I've seen it up at 60-62C in the height of last summer in the crazy heat. I'm pretty clued in with electronics, "most things" are ok into the 70's even 80's but no sense in pushing things for the sake of a 20 euro fan on Amazon.

Good call.

DC999 · 31-03-2023 12:48pm

https://www.boards.ie/discussion/comment/120422339#Comment_120422339

Interesting, I see our inverter says it throttles above 45C and spec’ed up to 60C. Says ‘When installed under direct sunlight, the power may be derated due to the temperature rise when the temperature is higher than +45°C’.

My inverters are outside on the South facing wall (all we have available), so no way to put fans around them. Tbh, it’s grand most of the time I’m sure as it’s Ireland. Panels were cooking in Aug last year so there was an output bottleneck there at least. And they are 3kW inverters and not under a heavy load. No fan in them, but have a large heatsink on the back. Different for people with 8kWp+ and the inverter is running 6kW for hours. But I'll watch them, only got solar in Aug last year.

But for me outside was better than our small attic that cooks. Small house with no utility or space in hall to mount beside consumer unit. And outside a breeze will cool it, unlike inside or in the attic. Manual says 'Check periodically that the heat sinks are free from obstacles and dust', so I'll find a way to blow any dust out before weather gets hot.

bullit_dodger · 31-03-2023 1:41pm

https://www.boards.ie/discussion/comment/120423207#Comment_120423207

For you externally, I suspect fans would make little difference DC999. The issue is more for us with the still air internal in closed spaces. My one is in a little cubbyhole off my converted attic. Passive heat sinks do "ok", not as well as active ones, but ultimately they need cooler air passing over those sinks to take the energy away. What happens is in 1-2 hrs the air in that little space heats up and the air is probably 30C (more?) itself and can't do as good a job

Just ordered a (normal) fan from Amazon. 220v operated and will hook it up to a smart plug to kick in at 5am -> 8am and then again from 11am-4pm. Blow the warm air out of the area and draw in cooler air. Basically the times that the inverter is under load either charging the battery. I think this will make a big difference. I'll post again once I have it installed.

kaisersose77 · 01-04-2023 9:33am

I'm thinking about going down the solar panel route but would like to link it to home assistant if i do. Is there any certain hardware/equipment i would need installer to use if i do?

championc · 01-04-2023 9:43am

The most controlable inverter is a Sofar. With a "sofar2mqtt" , not only can you pull live data, but you can also control the inverter to Charge on commands - thereby allowing you to charge based on weather predictions

JayBee66 · 01-04-2023 10:49am

Here's a problem that I want to offer to the Brains Collective on this thread...

I want to automate the immersion heater but would like to utilise, as much as I can, what I already have. The house has a legacy Active8 solar thermal installation that has three temperature probes; panel, top of the cylinder and bottom of the cylinder. The controller (image below) has no WiFi capability but I would like to try and mod it, in some way.

I want to keep the solar thermal as it pre-heats the cylinder for most of the year and Sun permitting it provides hot water without the immersion heater, meaning I can bank some more credit via the ESB.

There is a solution for analogue dial meters, which uses a small camera and OCR to read figures. I prefer not to do this because a) it would get in the way of putting clothes in the press and b) you have to physically cycle through with a button to get the three temperatures.

There is the Tesla T WiFi enabled cylinder thermostat but some people have reported issues, failures and the price is a bit of a turn off. Also, the HA integration for it looks tough going.

I was wondering if there was a way of piggy-backing the existing temperature sensors to get their data. It would save having to drill into the foam on the cylinder to place a temperature sensor next to the cylinder.

Maybe there is a modern WiFi enabled solar thermal controller that can replace the current one that can be integrated into HA.

I'd like a solution that uses as much of what I already have rather than doing anything radical. On getting the three temperatures and a solar radiance forecast, I will determine if there will be enough Sun for thermal heating or whether I'll need to run the immersion heater. In the winter the temperatures will determine when to top up the cylinder with the immersion heater.

After that I will probably replace the existing immersion heater switch on the wall with one that can be switched through HA.

Thank you for any suggestions.

Jonathan · 01-04-2023 10:55am

https://www.boards.ie/discussion/comment/120426450#Comment_120426450

Just make sure it has a RS485 port and that it supports Modbus (which most do).

Jonathan · 01-04-2023 11:27am

https://www.boards.ie/discussion/comment/120426677#Comment_120426677

This is exactly what I have. I have solar thermal + an Eddi. My solar thermal controller (Resol DeltaSol) exposes the sensor information over vBus (a proprietary RS-485 variant) which I feed into a RPi0 and then onwards to HA.

Some more details here.

Old HA screenshot below (I've since added another PT1000 sensor to the middle cylinder pocket, but today's graph isn't as illustrative).

JayBee66 · 01-04-2023 12:07pm

https://www.boards.ie/discussion/comment/120426779#Comment_120426779

Thanks for that. I have seen mention of the Resol during my Googling. I'll see if I can replace the current controller.

championc · 01-04-2023 12:52pm

Open up the Steca. It may we'll have an RS232 port. If it doesn't, then look online for the next model up the TR 0603mc which has a SD Card storer and an RS232, which I linked into a Raspberry Pi running Node-Red.

Obviiusly, RS232 is so much easier than Modbus RS485

graememk · 01-04-2023 2:24pm

https://www.boards.ie/discussion/comment/120426677#Comment_120426677

What is your immersion cylinder like? Is it a Copper one with foam or a stainless one with a mild steel case?

If copper, you can not worry about the solar controller and just get some temperature sensors and an esp8266 with esphome running on it (ds18b20 temperature sensors) and just shove them under the insulation of the tank.

Other steps you might have is have free ports for a thermowell/thermopocket on your HW tank for temperature sensors, but that requires some plumbing!

https://www.boards.ie/discussion/comment/120427113#Comment_120427113

Hmm. you've got me thinking, maybe i should swap out mine to something i can talk to

Mines a Prosolar PSc104, waait, It looks like it is a rebadged sonnenkraft SKSC2.. It has a Vbus.. I think its Resol Vbus, RS485 by the looks of it. Bah enough procrastinating back to work.

JayBee66 · 02-04-2023 7:49am

A message to all inverter owners in general but to KStar owners in particular...

The first night of ownership, thirteen months ago, I thought there was something wrong with the system. It just felt a bit jittery over night. The Solarman chart showed consumption flat lining during the night, even though there were plenty of electrical devices operating. Often there would be many grid import spikes at night with no apparent consumption.

For the past 13 months my installer would occasionally get a hunch and try something to no avail; a replacement inverter, new panels, new cabling. Nothing improved the situation.

Two weeks ago, I decided to get Home Assistant running, which led to 4 input registers causing the Solarman integration to fail. It was suggested on github that I get a firmware upgrade on the inverter, which I duly did and the integration worked.

This morning I logged into my ESB Networks account to see a marked changed in import. Apparently, for the past thirteen months the inverter has been importing a constant 65W when there was not enough solar radiation by night and during the darker days of winter. Since the firmware upgrade, virtually nothing imported, day or night. Only using the electric shower needs significant help from the grid. I estimate about 350KWh of unnecessary import.

My PV installation company might be packed with electrical engineers but not one of them is a software engineer. They and others must have installed many hundreds of KStars since my installation.

I recommend that you all sign up for an ESB Networks account (if you are in the Irish Republic,) have a smart meter so that you can see your official import/export (not what your inverter thinks it is doing) and ensure you have the latest firmware in your inverter.

graememk · 02-04-2023 8:24am

https://www.boards.ie/discussion/comment/120430076#Comment_120430076

*And on a smart meter.

JayBee66 · 02-04-2023 9:03am

https://www.boards.ie/discussion/comment/120430162#Comment_120430162

Yes. A good reason to have one. Otherwise, you'll never know what you are really importing and exporting. You can't rely on the inverter.

graememk · 02-04-2023 9:17am

https://www.boards.ie/discussion/comment/120430260#Comment_120430260

Or external monitor.. I wouldn't give up my current cheap rates just for that.

For people on a digital DN meter the light on mine stays constant when exporting,

And if your really patient, you can count the flashes of the light.

Sadly only the sofar and sunsynk have the option of "tuning" the CT attached to them

Jonathan · 02-04-2023 9:40am

https://www.boards.ie/discussion/comment/120430290#Comment_120430290

Or just use an app like this;

https://play.google.com/store/apps/details?id=smart.meter.app

JayBee66 · 05-04-2023 11:50am

Has anyone used https://www.shelly.cloud/

Trust Pilot doesn't rate it.

Unlike Shelley UK, it can deliver to Ireland and is far cheaper than buying Shelley devices from Amazon UK.

I assume it's part of Shelley but just want to check.

championc · 05-04-2023 1:28pm

https://www.boards.ie/discussion/comment/120430076#Comment_120430076

I used my MyEnergi Grid CT clamp to see and monitor my grid import / export.

Luckily, the Sofar ME3000 has a CT calibration option, which I biased towards export over import, to ensure I import feck all. Even a 20w per hour per day across a month adds up.

Jonathan · 05-04-2023 2:52pm

https://www.boards.ie/discussion/comment/120443162#Comment_120443162

Shelld.cloud is Shelly themselves. The UK store is a separate reseller (Brexit dividend 😂). I've bought from the former without issue (shipping was a little slow - circa three weeks IIRC).

Tree · 09-04-2023 11:46pm

https://www.boards.ie/discussion/comment/120443162#Comment_120443162

Big fan, but yes, they're not fast, and at least one of the lads has the weirdest responses to customer emails (but nothing that'd stop me buying, just have me going "that's a weird response to this particular email")

randombar · 18-04-2023 11:58pm

Couple of changes to my setup for charging batteries based on tomorrows sun due to the fact that I'm getting loads of juice at the minute.

1) Updated HA to only switch to standby when the % of battery remaining is met, i.e. spend the battery during the night if there's enough left but leave enough for the morning.

2) Only switch on battery charging mode at night if battery is below what is required.

3) Added a phone alert in case the connection to sofar breaks, had it today where the battery never went back into standard mode cause the ha connection to the sofar broke (need to restart the sofar) and I was in work.

randombar · 19-04-2023 12:04am

https://www.boards.ie/discussion/comment/120427620#Comment_120427620

I bought a couple of "SONOFF TH16 Smart WiFi Switch Monitoring Temperature Humidity with DS18B20 Waterproof Temperature Sensor" and just doubled up on the data. They have a smart switch included too if you wanted to use it for something.

championc · 19-04-2023 6:45am

Nice alerter to WhatsApp

https://randomnerdtutorials.com/esp8266-nodemcu-send-messages-whatsapp/

https://www.callmebot.com/

Big Lar · 20-04-2023 4:00pm

https://www.boards.ie/discussion/comment/120422969#Comment_120422969

Are we saying this is too hot?

I wouldn't mind but I mounted it onto a bit of 4X2 Box a few months ago to allow for better airflow

bullit_dodger · 20-04-2023 4:20pm

https://www.boards.ie/discussion/comment/120499944#Comment_120499944

it's a solis Lar isn't it? Looking at the datasheet it looks like the ambient temp is to +60C

Datasheet_S6-GR1P(2.5-6)K_GBR_V2.0_2023_02.pdf

Now, what I don't know is if that temp is the supposedly max temp of inside the inverter, or the ambient temperature of the room. Many inverters derate themselve when they go over a certain temp to protect themselves. Might be worth a few euros on amazon to get a few PC fans like Mick has.....wouldn't hurt anyway.

con747 · 20-04-2023 4:46pm

https://www.boards.ie/discussion/comment/120500003#Comment_120500003

A bit of info here if any use. https://ginlongsolis.freshdesk.com/support/solutions/articles/36000074739-inverter-temperature-de-rating

DC999 · 20-04-2023 6:29pm

https://www.boards.ie/discussion/comment/120500003#Comment_120500003

Very unlikely to be 60C ambient in the room. That would cook grub.

Mine are on a wall outside the house and the internal temp only got to 30C today. But there wasn't a lot of heat in the sun to cook them and was good wind to cool them. I've 2 x 3kW inverters so don't have a heavy load on them. The datasheet from con747 says 'Monitoring data can display temperatures in excess of 85C, but this is not cause for alarm, these temperatures are within normal operational ranges inside of the inverter.'

Likely still worth a fan below it to move the air around it.

bullit_dodger · 20-04-2023 7:09pm

https://www.boards.ie/discussion/comment/120500437#Comment_120500437

Agreed - for sure I know that it's not 60c in the room! :) My comment was the solis specsheet was saying "operating temperature"

But is that 60c above in relation to "the device can work in a room which is 60c" or that inside the circuits can get to 60c. Con747's link above seems to have partially answered it.

In some cases monitoring data will report the internal electronics temperature, and not the ambient external temperature. If the inverters overheat they will begin to derate power, and then throw the alarm "TEM-PRO" or temperature protection. This indicated that the external ambient temperature has exceeded 60C, and the internal temperatures cannot be maintained safely. The inverter shuts down to protect its internal components. Once temperatures return to operational levels the inverter will resume power production.

Monitoring data can display temperatures in excess of 85C, but this is not cause for alarm, these temperatures are within normal operational ranges inside of the inverter. In fact, external surface temperatures of the inverter can reach up to 75C, as displayed in the safety instructions at the beginning of every manual (see example below). The inverters calculate the external temperatures by using a formula based off of the internal temperature reading of the inverter. The monitoring portal is unable at this time to perform the calculation to show the ambient external temperature of the inverters.

So it would seem that the circuitry can get to 80C and not be cause for alarm, which is sort of inline with my own thoughts (previously mentioned above). That said, if you can get a cheapish fan and drop the temps 10deg, no harm and it would possibly help your inverter not derating itself and lasting longer.