Solar PV Monitoring/Automation Thread

randombar

Hi Folks, looking to get a closer look at energy monitoring, particularly with my HP (Ecodan out of the box monitoring is shite). Guessing shelly is the way to go? Just whack a CT clamp on the live?

championc

https://www.boards.ie/discussion/comment/121570237#Comment_121570237

Or a MyEnergi CT, and if not used previously, configure it as a "Generation&Battery" type of CT, which will give you it's own icon on the MyEnergi homescreen in their app, along with being extractable into HA

randombar

https://www.boards.ie/discussion/comment/121570378#Comment_121570378

Moving on from myenergi (will be putting the eddi up for sale shortly), have a solaredge PV system in place which have their own car charger etc. might see what they have to offer in relation to CTs.

SD_DRACULA

Need a bit of help trying to work some automation magic in HA that has some smarts for dumping the battery into the grid (you're welcome Greta)

Ideally it can start at 00:00 and run until 02:00 and the max to dump is about 5500w per hour so about 11kwh in two hours (if capacity is there)

If not then divvy up the remaining over the two hours by reducing the 5500w rate.

It is of course crucial to not get empty before 02:00

Anyone got the code ready to share? 🤣

JayBee66

I wonder if people deep cycling their batteries to arbitrage on the day/night price spread are factoring in the price of a replacement battery into their ROI.

I haven't done the maths as I don't arbitrage but I'd be interested to know for when or if UK-style agile pricing is introduced and it might be possible to earn multiple euros per KWh and not cents.

As is, I'd be worried about losing my return on battery replacement. I'd be less worried with agile pricing and "Give Back Sessions" but not totally unworried.

From past experiences, working in The City, there's always a winner and loser in arbitrage. It's more likely to be the energy companies winning rather than batteries and their owners.

Food for thought rather than "you shouldn't be deep-cycling your batteries every day".

graememk

https://www.boards.ie/discussion/comment/121573840#Comment_121573840

Make them work. That's what they are there for. They need to pay their way.

Especially during the give back sessions where the amount you get multiples of what you could save from load shifting or even replacing day rate with solar captured

SD_DRACULA

https://www.boards.ie/discussion/comment/121573840#Comment_121573840

Not sure that matters in the long run, the batteries will still be good for 80% capacity after 5-10 years, just add more of them as needed.

This is winter mind you 😉

I think I sort of have a bit of logic already in place:

variables:
    charge_voltage: 53
    charge_hours: 3
    night_usage_wh: 3500
    battery_capacity_wh: 20480
    lower_soc_limit: 5
    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 }}'

Then now_battery_usable_wh / 4 will give me the discharge wh value spread over the 4 hours which is less strain on the batteries not that it mattes because 5500 / 4 batteries is nothing anyway

insular1

https://www.boards.ie/discussion/comment/121573840#Comment_121573840

Here’s my very rough math. Assuming you already have an inverter and are literally just filling the battery up on 5c night rate and discharging for 25c FIT.

- Cost of 15kWhr battery build 2000euro (can be done cheaper than this)

- Useable capacity 80% or 12kWhr

- Assuming approx. 20% or 2.4kWhr losses between charging and discharging that’s buying and selling 9.6kWhr of electricity daily at a profit of 20c per kWhr.

- So daily charge and discharge would net you daily €1.92 or €700.80 per year.

- Payback on battery under 3 years.

- Cells will only have cycled 1095 times in these 3 years and most cells are rated to 80% capacity for 3000 cycles or more. My CALBs are rated to 9000 cycles.

The above also doesn’t include the fact that much of the 9.6kWhr cycled each day could be used to offset day rate usage as high as 38c or that during the summer months you could be saving more if filling the battery with solar. On the other hand there is a good chance the FIT will drop over the next few years and so the profit per unit may not be as good. But you can always stop cycling the batteries if this happens. At present for me it definitely seems worth it.

Of course this is all for a DIY battery and buying more expensive one off the shelf will lead to a longer payback.

micks_address

hi folks,

have a question on thermostats and home assistant - for last few years we have been using nest and no major issues but its starting to act up - drop off line and come back on randomly etc.. im on with google support but i suspect its out of warranty so we may be looking at a replacement. Nest doesnt seem integrate that well with home assistant (ive added the integration but you can't call for hot water). I'm wondering if there's anything that we could replace the nest with - that integrated natively? one of the annoyances i have with nest is they never released the room stat functionality in europe that they did in the US - so that individual rooms could call for heat if they were colder than rest of the house - have separate radiator and hot water circuits - so i'd like to be able to call for hot water to turn on if the hot water in the clyinder dips below a certain temp etc.

I've see tado mentioned a fair bit - would it do the job?

Cheers,

Mick

SD_DRACULA

Using the netatmo stat and valves for a while now and it works ok with HA but it's on a combi so nothing to do with water only.

Jonathan

https://www.boards.ie/discussion/comment/121575424#Comment_121575424

I've got a Shelly 2.5 controlling my boiler. Fully controlled from HA using a generic thermostat.

Still have physical buttons for an override but never used. Posted about it here;

https://www.boards.ie/discussion/2058221041/climote-alternative

bullit_dodger

https://www.boards.ie/discussion/comment/121573854#Comment_121573854

Yeah, 100% in behind this idea. Basically you bought the battery to be used, so it could pay for itself over time. To NOT use it, is sort of counter-intuitive with respect to the original idea why you bought the battery to begin with. Makes more sense now with FIT (as opposed to 1-2 years ago). So we can potentially double cycle your battery most days.

#1 Load up on cheap night rate and then dump to the grid during the day by (say) 10am

#2 Charge the battery from solar, to use in the evening and then dump that to the grid before 2am (or whenever your cheap window kicks in)

Possibly using 1.5->2.0 cycles a day. I can appreciate the thought of wanting your battery to last, but at 6,000 cycles (with some like the Givenery claiming unlimited cycles or 12 years).....even at 2 cycles every day 365 (which won't happen), that's still ~8 years.

graememk

https://www.boards.ie/discussion/comment/121576196#Comment_121576196

I'd not even purposely discharge the battery in the morning, just let it all be exported.

Then empty in the evening.

bullit_dodger

https://www.boards.ie/discussion/comment/121576565#Comment_121576565

Yeah, there's a couple of interesting "game theories" to think about. That might be better tbf.....not sure.

jasgrif11

Does anyone have a "dummies" guide for Solcast integration with HA?

I have 3 PV setups in Solcast for South, West and East. Do I select forecast or Live in Solcast for the API? I'm getting 0kwh reported across all entities in HA and it says the API was last polled 4 months ago. I can confirm that the API is the correct one.

Thoughts?

Jonathan

https://www.boards.ie/discussion/comment/121578558#Comment_121578558

See linked post below.

https://www.boards.ie/discussion/comment/121253168#Comment_121253168

jasgrif11

Excellent thanks Jonathan

JayBee66

https://www.boards.ie/discussion/comment/121578558#Comment_121578558

I was pretty sure that I was informed on the website and only permitted to have two arrays within a certain distance of each other. Maybe that limit has changed or I misread the stipulation.

jasgrif11

I have 3 on Solcast

When I go to add it to the Energy dashboard, do I need to add Solcast integration for each orientation (add 3 times)?

When I try to add it once for South, it does nothing. I guess this may be because I have used up all 10 API calls. I have since updated the automation to call the API every 3 hours.

Jonathan

https://www.boards.ie/discussion/comment/121580522#Comment_121580522

Yes, add the integration three times - once per API key.

Learned Ladies and Gentlemen - a favour to ask (a shortcut perhaps!).

As a homeassistant user already, but one without any solar/battery setup yet. Are there any recommendations for/against in terms of hardware to look at for invertor/battery pairings? I am in the process of quote gathering for an array + battery setup, and want to be careful not to mess up.

I am a pessimist at heart, so don't want to rely on any cloud-only based offerings for 'remote' control / monitoring. No guarantee that the XYZ.zzz servers are up and running in 15 years time etc. So whilst it's fine/good/a nice bonus to be able to monitor/fiddle via websites - I'd much prefer a local control be available (bluetooth / esphome / tasmota / direct w/e ) which means that HomeAssistant doesn't need to 'leave my network' to control the battery discharges / nor the monitoring of the solar.

I am already set up with a Shelly EM for the house mains - completely comfortable if a solution like that was suggested to monitor the solar alone. (Can't see huge benefits in having too much other data from an array available other than power out. Correct me if I'm wrong though!).

But wrt the battery - would definitely like/need to be able to force discharge / time the load to take advantage of boost rates etc via HomeAssistant.

Are there any 'strong' recommendations for 'simple' local solutions? (and also warnings against any others!)

graememk

https://www.boards.ie/discussion/comment/121606708#Comment_121606708

Ah everything local. Someone after my own heart.

What I know that have modbus access (in addition any WiFi/solarman logging)

Sunsynk and sofar. Both have good community behind them. Control and monitoring.

Solis can be connected to via the WiFi logger, but it needed to be a gen2 one, which are getting rare (@Jonathan can you confirm re the gen 3 isnt not working) Or ditch the WiFi logger all together and use that rs485 port.

But if going solar only, no battery, a Shelly on the inverter is all you need.

micks_address

https://www.boards.ie/discussion/comment/121566236#Comment_121566236

Hi folks, anyone have issues with their nest Thermostat going offline? Happens on and off last few weeks with ours. It's probably 5 years old at this point. Seems common enough issue online but no obvious solution. Reset the network connection and restarted it. How hard is it to set up a new one? Thinking it might need to be replaced

HotSwap

https://www.boards.ie/discussion/comment/121610982#Comment_121610982

The difficult bit is already done as the correct wires are already connected to the current one. So it’s basically a switch out.

the only exception to this is if your old model is one of the ones that didn’t support hot water; and you want to use that facility on the new one. That would require an understanding of how the wiring of a central heating system works (which can be confusing and takes a while to get your head around).

have you tried moving the unit closer to the bridge? Maybe not possible if it’s wall mounted. You could try re pair them also; maybe it trying to use a channel that worked well before; but now has some interference on it.

micks_address

https://www.boards.ie/discussion/comment/121611688#Comment_121611688

It's wired for hot water and heat. You mean try changing the WiFi channel on the router?

HotSwap

https://www.boards.ie/discussion/comment/121606843#Comment_121606843

All my Huawei gear hooked up to home assistant no issues. Also the “Fusion Solar” app in “Installer” app works by connecting to a local wifi network that the inverter creates; which allows you to set everything up locally.

There are some things that arnt easy to change via home assistant. For example; the times that the unit is set to charge and discharge; but if I was bothered to figure out the format of I could also do that via home assistant.

HotSwap

https://www.boards.ie/discussion/comment/121611709#Comment_121611709

Oh. I was making the assumption that the issue was between the nest unit in your room and the bridge unit in your hot press. Didn’t consider the other issue between the bridge and the wifi.

As the bridge is in the hot press; make sure that it’s using 2.4GHZ to connect to your WiFi. And yeah; what you said could help; you would need to download something on your laptop to try and assess which channels are cluttered; and where you might find some free air.

did anything change with regard to your WiFi? Maybe someone bumped the antenna on the back of the router? Might be a simple fix.

micks_address

https://www.boards.ie/discussion/comment/121611733#Comment_121611733

It's the wifi connection between the nest Thermostat and router that seems to be going offline.

micks_address

Hi folks,

I'm running home assistant on a raspberry pi 3b with external SSD drive and it's ok but I reckon st some stage I'll need newer hardware. I've a pijuice pihat on it for ups.. would an intel nuc be the way to go or a newer raspberry pi?

Jonathan

https://www.boards.ie/discussion/comment/121615204#Comment_121615204

Don't bother with another RPi.

Get yourself an Optiplex Micro. I have one here running HA, Frigate and its plenty powerful enough. Power consumption is about 10-11W.

Something like this.

https://www.adverts.ie/desktops/dell-optiplex-7060-micro-8th-i5vpro-8gb-256gb-ssd/32654603