Control your heat pump, EV charging and solar power by electricity price - fully open source

EnergyWizard is a self-built, open home energy control system: minute-by-minute decisions about heating, hot water, EV charging and solar surplus, driven by a priority engine and validated against months of real operation - not a black box with claimed percentages.

See the real numbers Source on GitHub ❤️ Sponsor

Solar panels, heat pump, the house as a battery, and an EV connected to one shared control system

🙋 I'm looking for beta testers

Do you have a smart heat pump, solar panels, a home battery or an EV - or some combination of them? I'm building EnergyWizard Open together with real houses, not just in theory.

You don't need all of it - a heat pump alone is enough to get started.
Open source, no subscription, no lock-in to one brand.
You help decide which houses and brands the system supports next.

Real numbers from my own house

No generic calculator - this is what the system has actually saved, measured against what the same electricity would have cost at the day's average price. Updated automatically. Read why I do it this way.

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New in November 2026

🕐 The plan clock

The next 24 hours as a clock face: one stroke per quarter in the price's colour, the hand on now, and rings for when the heat pump charges the house, the EV charges and the battery charges or discharges. Next to it: the next 12 hours and when the cars will be ready. Switch between spot and total price.

🔋 Home battery with a daily plan

Quarter by quarter: when the battery should charge, save and discharge. Five planning styles from careful to bold, a choice whether the battery may sell to the grid, and the plan compares itself with what actually happened and corrects itself over time. Controls Solax, Growatt and FoxESS; reads Felicity, SolarEdge, Sonnen and others. How it works, with pictures.

🌡️ More heat pumps

Besides Thermia and anything with a climate entity: NIBE S series locally, NIBE/Bosch/Atlantic/Daikin via myUplink and Panasonic Aquarea via HeishaMon. Which are supported.

🌍 Swedish and English

The web, the mobile app, the README and the knowledge base are now in both languages. Pick the language in the setup wizard. Want your own language? The translations are plain text files on GitHub.

How it works

🧠 Priority engine

A rule engine (not a guessing AI) decides in real time: heat the hot water tank, shift EV charging, store heat in the house, or back off - based on electricity price, solar surplus and demand tariffs.

🔋 The house as a heat battery

The hot water tank and the house's own thermal mass are used to "charge" when electricity is cheap and "coast" on stored heat when it's expensive - for several hours at a time.

✅ Validated against real history

New control rules are first replayed against months of real log data before going live - not just tested in theory.

🔌 Open and pluggable

Drivers for different heat pump brands, EVs and inverters - built so others can plug in their own hardware, not locked to one brand.

Knowledge base

Articles grounded in the real code - no marketing copy without substance.

Basics

The house as a heat battery

Heat pump

Controlling a heat pump by electricity price (Thermia, NIBE, Panasonic, etc.)

EV charging by electricity price

Methodology

Why I show real numbers, not a claim

FAQ

Frequently asked questions

Home battery

Do you have a home battery? Five modes, planning style and which can be controlled