Home energy measurement and browsing ??noob seeks SLS community wisdom

M

Mick

New member
Joined
Jul 19, 2020
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3
Context: Residential address in Australia 6kW on-roof solar currently no local energy storage

Hello to the SLS Community

As someone somewhat new to home energy monitoring, I'm hoping to leverage the knowledgewithin this community.

I haveexperience with the 'Embermeter' provided by our solar installer, and data-dumps from the SMA Sunny Boy inverter I had at a previous address. The Emberxxxxx ecosystemhasa pretty slick web interface, but it's limited and I believe designed for the casual enthusiast rather than someone with a passion for going deeper(ie. it's limited to: display of15 minintervals /fixed number of monitored channels / can'texport captured data /can't set alarms or alerts / etc).

UltimatelyI'd like:
powermonitoring of each fused circuit at the property (including three supplies two from grid and one from solar)
configurablesampling rates and local / cloudstorage of data
ability to export captured data (csv, or similar)
ability to expand system down the track to show stats from alocal battery storage system (most likely COTS, rather than DIY)
possibility to use 'recipes' (thinkIFTTT) to trigger relay outputs ie. to switch loads between solar / lower tariff circuits to optimise for on-siteproduction / demand
Cloud based data viewing and setup(through webpage / mobile app)
Could run on a local machine Raspberry Pi or similar low impact PC would be fine

I really like the work the DIY community is doing in the battery storage, and love watching vids of people's projects. I appreciate that I'm skating around the edges of DIY, but nevertheless hoping I've found a group of people who may be willing to help out. Let me know if there areany furtherdetailsthat I can provide.

Thank You!

Mick
 
I have a DIY version of the OpenEnergy monitor. Works pretty good. Mine runs on an arduino nano with two CT sensors. The built in ADC is not fast enough, imho.

So I'm currently in the process of upgrading to using an ESP32, and also adding in more sensors for each of the circuits instead of only the two hots.
 
Thank you all for taken the time to respond. You've collectively made some great suggestions, and ones that I hadn't stumbled across until now. I'll do some more homework and come back with any further questions.

@Korishan really interesting to hear about the ESP32 integration I've had some experience with these and for the most part they've been amazing value for money. You may already be across this, but be weary of the ADC and expect to calibrate each one individually as they can vary dramatically (10% or more) from one unit to the next. Tying one ADC input to a vref chip / adding an external ADC chip are both ways to deal with this known ADC issue with the ESP32 die.
 
Esp32 built in adc is useless comparing to a nano. Switching to esp32 gains nothing for above issue. You only gain more channels.

Watch the Swiss guys videos showing that.
 
I won't be using the built in ADC. I already discounted using the builtin one because it was only 12-bit max. I didn't like that range, so I went with 16-bit ADC.

Currently trying to get the ADS1115 to work with it. I am having little trouble with some of the function calls. Might have to build a new library with everything integrated specifically for these 3 to work together nicely.

Current libraries are:
ESP32 / Arduino base
EmonLib adapted for use with I2C
ADS1110/5 by I2CDevlib
 
I have pretty much everything on the Solarand DC related side being monitored by my ESP32s with ADS1115s
I monitor Array Voltage, Controller Amperage, Battery Voltage, Amperage in and out, Inverter Amp,etc.
All reports wirelesslyto my influx db on an older IBM thinkpad running ubuntu visualized with grafana.
All is accessible over the net and is password protected.

image_zbfcys.jpg


On the house watts and AC side I went with IoTaWatt. All in all very easy to set up also reports to Influx db and visualized with grafana.

image_muzybk.jpg


Wolf
 
Once you learned esp coding, influxdb and If needed Mqtt is so easy to get the data in..its then only about doing some dashboards :)
 
Thanks RedPacket for that link to open energy monitor! that opened a wormhole for me. I'm waiting on some chinnanos so trying that will be fun. Ultimately being able to vary charging amps continuously on a victron multi using pv divert would be sick.
 
Thanks everyone again for the contributions to the thread; some solid takeaways for me for sure! I'll report back with details of how I go, along with any notable learnings along the way. And Wolf, Wow. You have ALL the data. Have you stumbled across any insights that you found surprising (or surprisingly obvious) having student / correlated the various data sets?
 
Mick said:
Thanks everyone again for the contributions to the thread; some solid takeaways for me for sure! I'll report back with details of how I go, along with any notable learnings along the way. And Wolf, Wow. You have ALL the data. Have you stumbled across any insights that you found surprising (or surprisingly obvious) having student / correlated the various data sets?
Click to expand...

Mick,

The one outstanding thing that I learned is to run certain appliances ie.dishwasher/ washing machine during solar maximum if possible. Also turn off stuff you don't use ie. AV equipment. We all know that anyway but once you see it represented on a graph it is enlightening what a small change will do for the overall picture.
Considering my last electric bill was $32.79 for 134 kWh (that is for power and delivery charge) that equates to 24 per kWh. Not cheap. As you use more it does become a bit less expensive 14.9 from my supplier.Before solar I used to use ~450 kWh on average and in the summer with the AC running much more. This was the first summer I used my Li-ion battery pack and my consumption from the grid was greatly reduced. Most people don't know what uses what in a house and just blindly pay their electricity bill not really knowing how these appliances work and what causes their bill to escalate.

Wolf
 
I agree. I have a basic power monitor system set up on my mains. It's interesting to see what kind of items do what kind of loads on the system. I only have 2 sensors (both hots) atm, and working on getting per circuit monitoring working.
Once you can see what is going on with your power, makes you more aware of loads and phantom loads.
 
Mick said:
You have ALL the data. Have you stumbled across any insights that you found surprising (or surprisingly obvious) having student / correlated the various data sets
Click to expand...
I produce/consumeoff-grid in cooperation with the grid.A key insight for me is that steadier loads are doable when producing your own power. Some really steady loads are things like computers/tv- run 24/7 steadily. Even kitchen stuff and the hot water heat-pump are predictable and reasonable to plan foroff-grid Solar power.

Its the high power, variable loads such as the whole house AC that make Solar more difficult as it can really spike. For example, we get 20'ish 100F+ days/year where I live. My home consumption goes from 3000w/hour (85F)to 6000w/hour (100F+)on those days. That's an extra (3kwh*24) =72kwh/day for just 20days of the year!

It really raises my respect for 'the grid' that it can handle these spikes in power :)

So I've been thinking about mitigation - perhaps use fans on 100F+ days and only use Solar AC in the hottest1/3 of the day? or have a backup mini-split and cool only a portion of the house on those days? .... things like thatif it really came to a Puerto Rico type event and I had to live 100% on my own power.
 
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