The Journey · Chapter 02
The big picture: PV + battery + heat pump + EV
The four building blocks and the one idea that ties them together — so every later detail has a place.
Before the details, the whole thing from above. Once you see the four building blocks and how they connect, every later detail has a place to land.
The four building blocks
- PV system — makes electricity from sunlight. Daytime, seasonally uneven (lots in summer, little in winter).
- Battery storage — shifts daytime solar into the evening. Lifts self-consumption.
- Heat pump — your biggest new electricity consumer, turning power into heat (at COP 3–4).
- EV / wallbox — another large but flexible consumer.
The one connecting idea
It all turns on one thought: use and deliberately steer your self-produced electricity, instead of exporting it cheaply and buying it back expensively.
- Sun shines → PV produces → house first, then battery, then heat pump/car, only the rest to the grid.
- Sun gone, power cheap (dynamic tariff) → deliberately charge the battery or run the heat pump.
- Sun gone, power expensive → live off the battery, throttle consumption.
Those who steer this themselves (locally, without a vendor cloud) extract the most value. That's the thread all the way to the "Pro · Control" stage.
Why the winter reality matters
An honest point up front: in December a PV system in Germany delivers only a fraction of its annual yield. That's exactly when the heat pump needs the most electricity. You close the winter gap not primarily with more modules, but with efficiency (low flow temperature, high SCOP55) and smart steering (dynamic tariff + battery). This shapes the whole design.
How the blocks work together
The value is at the interfaces: can your PV "talk" to your heat pump? Can an energy manager (or you, via Home Assistant) coordinate battery, heat pump and car? Whether these parts work together across brands is perhaps the most important question — and the reason controllability is its own focus.
In short: four blocks, one idea — use and steer your own power. The winter gap is closed by efficiency + smart steering, not just more modules. The biggest value is in coordinating the system yourself.
That's your orientation. From here we go into the Foundations — starting with the units kW, kWh and kWp.
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