This presentation introduces Home Assistant (HA) as a powerful, open‑source home energy and automation platform, running on a Raspberry Pi as a grassroots, locally controlled setup.
In this configuration, HA sits on your local network and communicates with Wi‑Fi–enabled devices such as inverters, batteries, smart plugs, chargers, and household loads. The key idea is local control: decisions are made inside your home, not in the cloud, giving flexibility, resilience, and transparency in how energy is managed.
Home Assistant or HA is a free open source software operating system that can be used in any Wi-Fi enabled devices on a local area network or LAN network in your own home. So, it is quite private. For that reason many people use it to automate their solar and battery and EV charging.It works with smart plugs and it works with APIs, which stands for Application Programme Interface.There are many APIs you can download and you don't have to write any code.
Alongside this DIY Raspberry Pi approach, it’s worth noting that Home Assistant Green is an alternative for people who want the same capabilities with less setup effort. Home Assistant Green is an official, low‑power appliance that comes ready to run HA out of the box, avoiding SD card preparation and much of the initial hardware tinkering, while still keeping everything local.
This section shifts from theory to practice. Rather than explaining every technical detail, the focus is on real‑world outcomes: what Home Assistant actually enables you to do with your solar, battery, and household energy. The aim is to show possibilities and spark ideas, not to provide a step‑by‑step build guide. HA acts as the brain that ties together prices, weather, solar production, batteries, and household loads into a coherent strategy.
Inside Home Assistant, you can, for example, say at 3:15pm get the weather for tomorrow. And that then helps you work out whether you wish to discharge your battery between 4 and 9 p.m. that day (for maximum FiTs) or whether you need to preserve it for the next day. Many people who use Local volts peer-to-peer trading use HA to discharge their battery at peak evening time.
Especially if you have a Tesla battery, you need an API like home assistant to discharge your battery into the grid.
Should you ever wish to write code, your go to is chat GPT its really good at it 😊.
A core use case is deciding when to buy electricity from the grid and when to sell excess power back. Home Assistant can read live and forecast electricity prices from sources such as the Australian Energy Market Operator (AEMO), Amber, or LocalVolts. For simpler tariffs, such as peak/shoulder/off‑peak, time of day alone may be enough. For dynamic pricing, HA can respond to rapid price changes.
By combining price signals with weather forecasts and solar predictions, HA can optimise energy use: charging batteries when power is cheap, using solar when it’s abundant, and exporting energy when prices spike. This slide demonstrates what can be done, rather than prescribing how to build it.
At its heart, Home Assistant works as a collection of automations that wait for triggers. Each automation typically follows a simple logical structure:
when something happens,
and if certain conditions are true,
then take an action.
For example, when electricity prices rise and the battery has spare capacity, HA can begin feeding power back into the grid, increasing export as prices rise.
While the logic looks simple, there are many caveats and edge cases. Real‑world systems involve limits, delays, device availability, and competing priorities. This slide introduces the concept without pretending it is trivial.
Selling energy purely based on price can be risky. A high price tonight may not be worth it if tomorrow is rainy and solar production will be low. Home Assistant can query external APIs to add context, such as weather data from the Bureau of Meteorology and solar production forecasts from services like Forecast Solar.
By checking these forecasts at a set time (for example, 3pm for the following day), HA can set internal flags such as “good weather” or “bad weather.” This allows the system to make more human‑like decisions that balance immediate profit against future resilience.
Once prices and weather forecasts are known, Home Assistant can adopt different strategies.
On a good solar day, the system might prioritise charging the battery from solar in the morning and selling energy during expensive evening periods.
On a bad solar day, it may instead charge the battery when grid prices are low and conserve stored energy rather than selling it.
The key point is that HA can reassess the plan daily. By fetching forecasts at a fixed time each afternoon and updating its internal state, the system behaves strategically rather than reactively.
This section moves from use cases to practical setup. It introduces the basic steps required to get Home Assistant running, focusing on the Raspberry Pi approach. This is where the grassroots nature of the system becomes visible: inexpensive hardware, open software, and hands‑on configuration.
The first requirement is a Raspberry Pi. This small, low‑power computer runs continuously and hosts Home Assistant. It provides enough performance for typical home automation and energy management tasks while consuming very little electricity itself. Pi 4 or 5 is ample in capacity.
Home Assistant is installed by flashing its operating system onto an SD card using the Raspberry Pi Imager tool. This prepares the card with HA Core, ready to boot. This step is straightforward but highlights one of the trade‑offs of the DIY approach:
SD cards are a potential point of failure. Make sure you back up your HA regularly.
After inserting the SD card and connecting power and Ethernet, the Raspberry Pi boots immediately. There is no power switch. Connecting a screen via an HDMI cable makes it easy to see the IP address on first boot, (although the address can also be found through the router). This IP address needs to be recorded and set to STATIC!
In theory, Home Assistant should be reachable via homeassistant.local:8123, but in practice this is unreliable on some networks. Accessing it directly via IP address is often simpler.
Once accessed through a browser, Home Assistant guides the user through initial setup questions. A good first exercise is creating a simple automation, such as turning a smart plug or light on or off when an event occurs.
On startup, HA will automatically discover many common devices and integrate them with little effort, while others may require manual configuration.
This section introduces the three core concepts needed to work effectively with Home Assistant: integrations, scripts/automations, and dashboards.
Understanding these provides the foundation for building more complex energy logic later.
Integrations are how HA talks to devices and services, exposing switches, sensors, values, and controls.
Automations and scripts define behaviour: what happens in response to events and conditions.
Dashboards provide a visual overview of the system’s current state, offering both information and manual control.
Together, these elements turn HA into a live control centre for the home.
This slide highlights some non‑obvious issues. A key lesson is that “when” is not the same as “while.” Automations trigger on changes, not ongoing states, which can lead to surprises if conditions are already true when a trigger time passes.
Other practical warnings include the fragility of SD cards, the need for regular backups, and the fact that after a power cut, the Pi may reboot faster than other devices. If devices appear unavailable, a restart of Home Assistant may be required. Assigning a static IP address is also recommended to avoid network confusion.
The Raspberry Pi approach represents a flexible, low‑cost, grassroots way into Home Assistant, ideal for tinkerers and people who want full control.
For those who want the same local‑first philosophy with less hardware setup and maintenance, Home Assistant Green offers a simpler alternative: a ready‑to‑run appliance that trades a bit of DIY freedom for convenience and reliability.
Here are some useful links:
Which HA install is right for you?
https://youtu.be/i72K1wyuTfg?si=YKnQzvxFDtRALJ3a
U-tube HA set ups:
https://youtu.be/49r75ymmZZg?si=4MkBR0XQXoNfJtNd
Home Assistant Green:
https://youtu.be/AbGb0dmc1r4?si=qpRKpJRR4g4HhB-K
https://youtu.be/Z4gvkmJ8q48?si=Uucx7chTRD1B2hbM
Smart Motion – consultant that sets up HA for you (around $700)
Make money from your home battery storage https://share.google/7xplFHuRe0HWtY2A6
And then you might have heard about a subscription to POWSTON…
Powston is a specialized, AI-driven service for optimizing solar, battery, and inverter systems for energy savings, acting as an intelligent layer on top of or alongside platforms like Home Assistant, which is a broad, DIY smart home hub;
Powston offers set-and-forget "Magic Mode" automation and real-time energy trading with providers, while HA is a customizable platform for integrating any smart device, requiring users to build their own energy automations or use specific integrations like Powston's to achieve similar results.
Key Differences
Scope & Purpose:
Home Assistant (HA): A comprehensive, open-source smart home platform for controlling everything (lights, locks, sensors, energy), requiring user configuration.
Powston: A focused energy management solution, specifically for optimizing solar/battery systems, using AI and market data to make automated decisions (e.g., charge/discharge).
Automation Style:
HA: Offers deep customization, but users build rules (e.g., "If sunset, turn on porch light"). For energy, this means manually setting up complex rules.
Powston: Provides "Magic Mode," a set-and-forget AI that tunes itself based on usage, prices, and forecasts, aiming for optimal savings automatically.
Energy Market Integration:
HA: Can monitor energy, but requires separate integrations (like Powston or Localvolts for trading) to actively participate in energy markets.
Powston: Directly integrates with energy retailers (like Localvolts) to manage charging/exporting during peak/off-peak times, often paying users to use or store energy.
User Control vs. AI:
HA: High user control; you are the "system".
Powston: Offers "Hacker Mode" (full control) but excels in "Magic Mode" (AI control), with automatic overwrites for optimal performance.
How They Work Together
Powston often provides data (via MQTT) or control signals that Home Assistant can receive and display, allowing users to see Powston's actions within their familiar HA dashboard while Powston handles the complex energy trading in the background.
In essence, Powston is a specialized energy automation service, while Home Assistant is a general-purpose smart home hub that can use Powston as one of its many smart components.
HA is FREE while Powston is a subscription