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01
Energy basics: kW, kWh, and what "kWp" actually means
The single most common mix-up in offers and conversations, cleared up once — because everything else builds on it.
02
How a PV system works
From sunlight on the roof to power at the socket — the chain in four steps, and what actually drives yield.
03
Understanding modules
Mono or bifacial, cell quality, and the difference between product and performance warranty — without the marketing.
04
Battery basics
Nominal vs usable capacity, LFP vs NMC, depth of discharge, and sizing the battery to your array.
05
How a heat pump works
A fridge, thought about backwards — why a heat pump turns 1 kWh of electricity into several kWh of heat, without breaking physics.
06
Efficiency decoded: COP, SCOP, and JAZ
Three numbers that all mean "efficiency" but answer different questions — and why SCOP55 is the one that matters in an old radiator house.
07
Flow temperature — the master lever
The one number that decides whether a heat pump can even reach your old radiators — and that affects efficiency more than any other single figure.
08
Why a heat pump doesn't behave like your oil boiler
Your oil-boiler habits don't transfer — and that's the single most common mistake.
09
Sizing done right: Heizlast & sizing
Why heat pumps are often quoted too big — and how to spot the right size.
10
Backup explained: Notstrom vs Ersatzstrom
"Backup-capable" often means no backup at all. The types, the differences, and the right questions.
11
Grid rules: §9 EEG, §14a and iMSys
Sounds like a bureaucratic trap, but is usually harmless — what the rules mean and why they barely touch your self-consumption.
12
Why local control matters
Cloud lock-in, subscriptions, outages — and what real independence buys you. The motivation before the mechanics.
13
Local control without the cloud: Modbus, Home Assistant & evcc
Why controlling your battery and heat pump locally is worth it — and which brands make it easy or hard.
14
Dynamic tariffs & battery arbitrage
Buy cheap, avoid expensive — how variable pricing plus a battery saves money, and who becomes the battery manager.
15
Coordinating PV surplus with the heat pump
Surplus solar into heat instead of the grid — via SG-Ready, EEBus or a HEMS. What actually works together.
16
Steering the heat pump yourself
Heating curve, room setpoint, modes — the safe levers for maximum control without harming the machine.
17
SG-Ready in depth
Two contacts, four states — what SG-Ready really is, who sends the signal, and where its limits are.
18
Cooling with the heat pump
Does it work in a radiator house? The honest limits, fan coils, the dew point, and the funding question.