Home Assistant for Solar: Monitoring and Automation

Home Assistant is a free, open-source home automation platform that's become the tool of choice for UK solar enthusiasts who want to go beyond the basic manufacturer app. It can monitor generation, control batteries, optimise tariffs, and automate your entire energy system.

What Is Home Assistant?

Home Assistant (HA) is software that runs on a small computer in your home. It connects to smart devices, energy equipment, and online services, presenting everything in a single dashboard. For solar owners, it brings together data from:

• Your inverter (generation, battery state, grid import/export)
• Your energy supplier (tariff rates, half-hourly pricing)
• Your smart meter (real-time consumption)
• Your EV charger, heat pump, and other smart devices

The result: complete visibility and control over your energy system from one interface.

What You Need

Hardware

• Raspberry Pi 4 (4GB): ~£50. Adequate for most setups. Can be slow with many integrations.
• Mini PC (Intel NUC or similar): ~£100–£200. More powerful, more reliable for complex setups.
• Home Assistant Green: ~£85. Official HA hardware, purpose-built.

Software

• Home Assistant Operating System (free) — the complete package
• Or Home Assistant Container (free) — for running alongside other software on Linux

Network

• Wired Ethernet connection to your router (recommended)
• Same local network as your inverter

Getting Started with Solar Monitoring

Step 1: Install Home Assistant

Flash the Home Assistant OS image to a microSD card (Raspberry Pi) or USB drive (mini PC), boot it up, and follow the web-based setup wizard. Takes about 30 minutes.

Step 2: Add Your Inverter Integration

GivEnergy: Install the GivEnergy Cloud integration from HACS (Home Assistant Community Store) or use the GivTCP local integration for real-time data without cloud dependency.

Solis: Use the Solisinverters integration or SolisCloud API integration.

SolarEdge: Native HA integration available — add via the Integrations page.

Fox ESS: Community integration via HACS, or use the Fox ESS cloud API.

Enphase: Native HA integration for Enphase microinverter systems.

Growatt: Community integration via HACS.

Step 3: Set Up the Energy Dashboard

Home Assistant has a built-in Energy Dashboard that shows:

• Solar generation (daily, weekly, monthly)
• Grid import and export
• Battery charge/discharge
• Self-consumption rate
• Cost savings

Configure it by mapping your inverter's sensors to the energy dashboard categories. This typically takes 10–15 minutes once the integration is working.

Useful Automations

1. Load Shifting to Solar Hours

Automatically run high-consumption devices when solar generation exceeds household consumption:

• Washing machine/dishwasher: Trigger a smart plug to power on when surplus exceeds 1kW
• EV charging: Start charging when surplus is available, stop when it drops
• Immersion heater: Supplement or replace an Eddi by controlling the immersion via a smart relay

2. Battery Management

Override your inverter's default battery schedule based on conditions:

• Charge battery overnight when tomorrow's solar forecast is poor
• Hold battery charge for expensive peak periods
• Discharge battery during Octopus peak pricing windows
• Reserve battery capacity if a power cut is forecast

3. Tariff Optimisation

If you're on Octopus Agile or Flux:

• Buy cheap electricity during negative/low pricing periods
• Avoid importing during expensive half-hours
• Export stored solar during high-price windows
• Send notifications when prices drop below a threshold

4. Weather-Responsive

Using weather forecast integrations:

• Pre-heat hot water before cloudy days (when solar will be limited)
• Delay EV charging to tomorrow if sunny weather is forecast
• Adjust battery charge strategy based on expected solar generation

The Predbat Integration

For the most sophisticated battery automation, install Predbat — a Home Assistant add-on that automatically optimises your battery schedule based on:

• Solar generation forecast (via Solcast)
• Electricity pricing (Octopus Agile/Flux)
• Your household consumption patterns
• Battery capacity and efficiency

Predbat is essentially a "set and forget" optimiser that can save £200–£500/year on energy costs by making perfect battery decisions 48 hours ahead. See our Predbat guide for full details.

Building Custom Dashboards

Beyond the Energy Dashboard, you can create custom views:

Real-Time Energy Flow

A visual diagram showing power flowing between panels, battery, grid, and household. Several custom cards (e.g., Tesla Style Solar Card, Power Flow Card Plus) provide attractive real-time visualisations.

Financial Dashboard

Track daily/monthly savings, SEG income, tariff costs, and running totals. Combine data from your inverter and energy supplier API to calculate exact financial benefits.

Historical Analysis

Graphs and charts showing generation patterns, self-consumption trends, and seasonal variations. Useful for spotting problems (is one panel underperforming?) and optimising behaviour.

Common Integrations for UK Solar Owners

The Learning Curve

Let's be honest: Home Assistant has a learning curve. It's not a polished consumer product — it's a powerful tool that rewards investment in learning.

Week 1: Install, add basic integrations, set up the Energy Dashboard. You can see your solar data.

Week 2–4: Explore automations. Start with simple ones (notifications when generation exceeds a threshold) and build complexity.

Month 2+: Add Predbat, Solcast forecasting, custom dashboards. This is where the real value emerges.

For the best Home Assistant integration, these products offer excellent API support:

GivEnergy All-in-One 5kW Hybrid Inverter

£1,200

rated power kw

5

max pv input kw

7.5

mppt channels

2

battery voltage v

48V

View on Amazon

Affiliate link — we may earn a small commission at no extra cost to you

myenergi Zappi 22kW EV Charger

£780

max charge rate kw

22

single phase kw

7.4

three phase kw

22

modes

fast,eco,eco_plus

View on Amazon

Affiliate link — we may earn a small commission at no extra cost to you

Is It Worth It?

For a UK solar owner with a battery on a smart tariff:

• Hardware cost: £50–£200 (one-off)
• Annual saving from optimisation: £200–£500
• Payback: Under 1 year

Even without financial optimisation, the visibility and understanding you get from Home Assistant helps you make better decisions about when and how you use electricity. Most users report that just seeing real-time energy data changes their behaviour in ways that save money.

For specific integration guides, see our articles on GivTCP, Octopus API, and Predbat.

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