Motivation

I already have photovoltaics installed on the roof of my house. For years I was looking into home energy storage solutions but commercial offers are too expensive to provide a positive RoI so it is necessary to atleast assemble some parts by hand. I don't feel confident to build individual battery packs together and run multiple kWh in my house for years so I am going with "mid-level components", i.e. commercial off the shelf battery systems and power inverter.

Goals

• G1: A personal home energy storage system automatically charging from self-produced PV and discharging into the home network to reduce grid power consumption and save money

Execution

• Research possibilities available on the German/European market
• Research about related electricity work safety concerns and implications for at least connecting some components myself
• Consider integration into existing solutions of https://www.home-assistant.io/ and https://evcc.io already running
• write down part list of parts to order
• Order parts
• Assemble, configure, test in prototype setup
• Put into production together with professional electrician
• Monitor performance and results over time periods of days, weeks, months, year(s)

Progress

After research I think I can now settle with a battery inverter "Victron Energy MultiPlus-II 48/5000/70-50" and battery packs from "Pylontech". For the battery inverter one can get an additional controlling device like "Cerbo GX" or – that is my plan – flash a custom OS on an SD card for a raspberry Pi + CAN shield to connect to batteries.

Downloaded most recent image from https://updates.victronenergy.com/feeds/venus/release/images/raspberrypi2/?C=M;O=D and writing to SD card with

sudo gunzip venus-image-raspberrypi2.wic.gz -c | dd bs=64M of=/dev/mmcblk0

put that into my raspberry pi and quickly a new system booted up. I could reach it under my local network on "venus.local" (and IP) and play around with the menu in there. I also enabled automatic upgrades and switched to the "large image" which includes "Node RED" which is now running on https://venus.local:1881

I ordered the battery inverter and batteries. So let's see when I receive the components. I am sure there are plenty of ideas to explore for next hack week(s) :)

Results

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