My power bill runs itself down.
How I cut my electricity bill in one summer month from around 180 € to 113 € — fully automatic. No extra hardware. Explained clearly, beginners included. (I’m in Germany, so the numbers are in euros — the method works with any hourly tariff.)
Not sure it’ll work for YOU?
An honest feasibility report for your battery, your dynamic tariff and Home Assistant — including a clear „worth it / not worth it“.
See the offer →The potential is there — but it never feels fully used.
My complete system — one clear thread instead of scattered snippets.
The 3 levers
Use your own solar · charge cheap, discharge expensive · shift your loads — step by step.
From spot price to charging plan
The control logic (state machine) that makes the right call every hour.
Safety & self-monitoring
An emergency brake and self-checks — the system notices when something jams.
An honest ROI calculation
Real numbers — including a clear word on when it’s not worth it.
Provider-agnostic
Works with Octopus, Tibber, aWATTar, Nord Pool & co. You’re not locked in.
Cheat sheet & glossary
The whole system on one page — plus key terms explained briefly.
Updates via Telegram
Charging plan, alerts and daily savings land straight on your phone.
Looking ahead: heat pump
How I’m planning the next stage with a second, fast storage layer.
Proof, not claims.
Real screenshots from my live system — anonymized, but unedited.
What this book is — and what it isn’t (yet).
What it is
- A personal experience-and-concept guide.
- The why and the how, built up clearly.
- ~50 pages, Kindle edition.
What it isn’t (yet)
- Not a pure copy-paste code cookbook.
- No guarantee of a specific saving.
- Planned: an optional starter kit with templates.
Before you buy.
Do I need programming skills?
No. The book explains the concept in plain language. To build it yourself, a basic interest in Home Assistant helps.
Will it work with my tariff / battery?
The approach is described provider- and largely hardware-neutral — the examples come from my real system.
Does it include ready-made code?
The focus is on the concept and the approach. An optional starter kit with templates is planned.
What format do I get?
A Kindle eBook (also readable in the free Kindle app on any phone or tablet), about 50 pages.
Does the book guarantee a specific saving?
No. The numbers are my real results, not a promise. The economics depend on your specific situation.
The decision brain, free to download.
It decides charge / discharge / idle from your hourly price, with a neutral band so it does not flap at the thresholds. Works with any dynamic tariff and any battery — you wire your own battery into the three action inputs. No signup, no email.
Download the blueprint →Get the complete field guide.
Get it on Amazon
Also free to read with Kindle Unlimited.
Available on Amazon — Kindle & Kindle Unlimited.
The English edition is available on Amazon.com. Read it on any Kindle or the free Kindle app — or free if you’re a Kindle Unlimited member. A German edition is available too.