Run the numbers on your energy.
Not on guesswork.
Nine precision calculators for balcony solar, rooftop PV, batteries, electric cars and heat pumps. Hourly simulation, irradiation data for every postcode in Germany, Austria and Switzerland, results in real time.
Engine validated against reference data from DWD, PVGIS and BDEW
Berlin-Mitte · 880 Wp · South 90°
€171per year
- Annual yield
- 633 kWh
- Self-consumption
- 490 kWh
- Specific yield
- 720
- Calculators
- 9
- Irradiation regions
- 262
- Hourly resolution
- 8,760
- Cost
- €0
Tools
The right calculator for every question.
Every calculator shares the same physical core, so results stay consistent with one another — from a single balcony module to a whole heat pump.
Calculation model
Not a rule of thumb. A model.
Most online calculators multiply your peak power by a flat factor. We simulate 8,760 hours a year instead — for your location, your orientation and the way you actually use electricity.
- 01
Location data
Your postcode maps to one of 262 irradiation regions across Germany, Austria and Switzerland, each with a measured annual global irradiation sum and a latitude.
- 02
Yield physics
Orientation and tilt are transposed onto the module plane with an anisotropic sky model. Shading, temperature, wiring and inverter clipping are accounted for separately.
- 03
Load profile
Your consumption is spread across an hourly profile. Only the hour-by-hour overlap of generation and load counts as self-consumption — never a flat percentage.
- 04
Economics
The energy flow becomes a cash flow: net present value, internal rate of return and payback across the full service life, including price escalation and degradation.
Global irradiation across Germany
980 – 1.200 kWh/m²·a
Why Amperecalc
Built like an instrument.
Results in real time
No submit button, no waiting. Every input recalculates instantly — the whole simulation runs in your browser.
No data collection
Your inputs never leave your device. No registration, no email address, no lead selling to installers.
Model in the open
Every calculator documents its formula, data source and assumptions. Every parameter can be overridden.
Fully bilingual
Complete in German and English, including units, number formats and currency presentation.
Frequent questions
Answered briefly.
Are the calculators really free?
Entirely. All nine calculators work without registration, without an email address and without usage limits. Amperecalc is funded by clearly labelled advertising.
How accurate are the results?
For the annual yield of a solar array, the typical deviation against metered results is five to ten percent. The largest uncertainty is not the model but the shading on site — which is why you can specify it in four steps.
Are my inputs stored?
No. The entire calculation runs in your browser; nothing is sent to a server. Only your language preference and your advertising consent are stored locally.
Why do you need my postcode for the yield?
Annual global irradiation in Germany ranges from about 980 kWh/m² in the north-west to 1,200 kWh/m² in the Alpine foreland. In Switzerland the spread runs from 1,160 on the plateau to over 1,450 in Valais and Ticino. That is up to 45 percent difference in yield — far too much to average away.
Does the 600-watt limit still apply to balcony solar?
No. Since the first solar package, plug-in solar devices in Germany may run up to 800 watts of inverter output, with module power up to 2,000 Wp. Registration is a simplified entry in the market master data register, and separate registration with the grid operator is no longer required.
Can I use the results for a subsidy application?
As orientation yes, as evidence no. Subsidy applications and grid connection requests normally require a design by a certified installer. Our results help you judge their quote.
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