You want to get a balcony solar system and are wondering: How much will I really save, and when will it pay off? Or you are planning an off-grid power supply for your motorhome and want to know how many days of self-sufficiency are realistically achievable. And right at the end, there is often the question that many underestimate: Which cables do I need, and what cross-section?
That is exactly why SOLARKONTOR has three tools that take care of the planning for you, help you avoid typical mistakes, and quickly lead you to a suitable solution:
- Balcony Solar System Calculator: Estimate savings & payback period
- Solar Calculator: Power requirements, yield, and self-sufficiency time for mobile and off-grid applications
- Cable Calculator & Cable Finder: Calculate the suitable cable cross-section (mm²) and find suitable cables
In this article, we will show you what the calculators can do, which inputs are really important, and how to interpret the results effectively.
Balcony Solar System Calculator: How much will you save, and when will it pay off?
The Balcony Solar System Calculator is your tool if you want a realistic answer to these three questions:
- Which power rating (Wp) is right for you?
- How much will you save per year?
- How long will the payback period be?
The calculator guides you through the most important assumptions in three steps and provides estimated values at the end, plus a recommendation on which power class from the shop suits your needs.
Step 1: Find the right power rating (Wp)
In the first step, you answer a few questions that have the greatest impact in practice:
- Number of people in the household (as a basis for an estimated annual consumption)
- Location and region (North, Central, South)
- Orientation of the modules (South, East/West, North ...)
From this information, a requirement in Wp (watt peak) is derived. Wp is the rated power of your modules under ideal conditions, so it is a useful comparison measure for categorizing sets.
Important: The calculator recommends a "next best set" at the end because balcony solar system sets are typically offered in fixed power classes.
Step 2: Annual savings, electricity price, and self-consumption
In the second step, it is all about money. For this, the calculator asks for, among other things:
- Your electricity price (€/kWh)
- Presence during the day
- Electricity price increase per year (%)
The key factor is self-consumption: The more you are at home during the day, the more solar power you use directly, and the higher your savings (usually) are. With storage, you can more easily shift excess electricity to the evening and nighttime hours.
Step 3: Payback period and total savings (with or without storage)
In the third step, it gets concrete:
- You choose a recommended set (or enter your own purchase price)
- You decide with or without storage
- You set a consideration period (10, 15, 20, or 25 years)
The result is the payback period (years) and total savings (€) as estimated values.
Why the result is an estimated value
The calculator makes it clear that the values are not "set in stone". Deviations arise mainly from:
- Weather and seasonal changes
- Shading
- Your actual consumption behavior
- technical differences between the sets
As a rule of thumb: Expect that actual results can deviate in both directions. The calculator provides realistic ranges here.
Mini-check: Who is the tool ideal for?
- You want a quick, well-founded assessment of profitability
- You are torn between power classes
- You want to understand whether a storage system makes sense in your everyday life
To the calculator: https://solarkontor.de/pages/balkonkraftwerk-rechner
Solar Calculator: Calculate power requirements, yield, and days of self-sufficiency
The solar calculator (solar and self-sufficiency calculator) is your tool if you are planning a system that is intended to run without a fixed grid connection. Typical applications are motorhomes, campers, vanlife, but also garden sheds or other small off-grid applications.
What you get at the end:
- Your daily power requirement (based on your appliances)
- An assessment of the solar yield (depending on region & season)
- A power balance and your days of self-sufficiency
- Recommendations on whether more battery or more solar makes more sense
Step 1: Add appliances, individually or by scenario
You can build up your consumption in two ways:
- Select individual appliances (e.g., portable fridge, compressor refrigerator, LED lamp, laptop, coffee machine ...)
- or choose a camping scenario (e.g., weekend trip, family vacation, vanlife, full-time camper, winter camping, digital nomad/home office ...)
Practical: You can also add your own appliance if your device is not on the list.
Step 2: Basic data, battery type, capacity, solar power
In the next block, you decide on, among other things:
- Battery type: Lithium (LiFePO₄) or gel/AGM/wet (lead)
- Your existing or planned battery capacity (Ah)
- Your existing or planned solar power (Wp)
- desired days of self-sufficiency
- Location/region and season
These inputs are crucial because yield and usable battery capacity in real life depend heavily on how you travel and when and where you use the system.
Understanding the results: consumption, yield, power balance, self-sufficiency
The results area shows you several perspectives:
- Consumption: What you really need per day (in total)
- Yield: What your solar system is expected to deliver
- Power balance: Surplus or deficit?
- Days of self-sufficiency: How long you can manage without recharging or a grid connection
The real power lies in the decision you make afterwards:
- If you regularly have a deficit: More solar (increase yield) or more battery (increase buffer)?
- If you only have problems in winter: You might not need a major upgrade, but rather a seasonal expectation (or an alternative charging source)
Recommendations and next step: suitable products or advice
The calculator then offers you direct next steps, e.g.:
- Show suitable batteries
- Show suitable solar panels
- Show suitable sets
If you want, you can also request advice.
To the calculator: https://solarkontor.de/pages/solarrechner
Cable calculator & cable finder: The underestimated part that ultimately decides everything
Wiring is an area that many underestimate during the planning phase – yet the right dimensioning is crucial for the reliability and safety of the entire system.
Undersized wiring often means in practice:
- too high a voltage drop
- unnecessary heat generation
- in the worst case, problems with the inverter, charger, or DC/DC converter
This is exactly where the cable calculator helps you: You calculate the suitable cable cross-section (mm²) and can then find suitable cables directly in the shop depending on the result.
Which areas does the cable calculator cover?
The cable calculator is not just "a calculator", but rather a small toolset:
- Solar cable to charge controller (module to charge controller)
- Solar cable to solar module (module to module)
- Battery cable (battery to appliance or inverter)
- Adapter cable (connection 1 "from" to connection 2 "to")
- additional selection areas such as CEE cables, data cables, EcoFlow cables, and others
This typically covers exactly the cable runs that are really relevant in solar setups.
Which inputs do you need?
Depending on the cable type, you enter, among other things:
- Current (A)
- Cable length
- Voltage (V)
- allowable voltage drop (%)
For the battery cable, you enter the length in cm (also "single"), plus system voltage (V) and rated current (A).
Result: Recommended cross-section (mm²) and "Find suitable cable"
At the end, the calculator shows you the recommended cross-section, e.g., 4 mm² or 16 mm² (depending on the application). After that, you can go directly to "Find suitable cable".
If no directly suitable product is listed for your information, the tool also shows this transparently and refers to alternatives or categories.
Adapter cable: from plug A to plug B
Particularly convenient: With the adapter cable , you only select the two connection sides (e.g., CEE, Anderson, MC4, cigarette lighter ...). The tool then tries to directly assign a suitable product to you, or tells you that this combination is currently not available, and links to the adapter cable overview.
To the calculator: https://solarkontor.de/pages/kabelrechner
Three tools that save you planning and wrong purchases
With the three calculators at SOLARKONTOR, you quickly get structure in your planning:
- The Balcony Solar System Calculator helps you with savings, power class, and payback period.
- The Solar Calculator makes your power requirements visible and shows you how realistic your self-sufficiency goals are.
- The Cable Calculator ensures that your planning does not fail because of a too small detail.
For special requests or special requirements, we are happy to help you. Just contact us, we will advise you personally, simply, and free of charge, by email, by phone, or directly on site in our showroom in Lüneburg.
Directly to the tools:
- Balcony Solar System Calculator: https://solarkontor.de/pages/balkonkraftwerk-rechner
- Solar Calculator: https://solarkontor.de/pages/solarrechner
- Cable Calculator: https://solarkontor.de/pages/kabelrechner
