The question of whether a photovoltaic system makes financial sense is one that homeowners and businesses alike are asking. Rising electricity prices, falling module costs and attractive funding programmes make solar power more appealing in 2026 than ever before. But how exactly do you calculate solar PV profitability, and which factors play the decisive role?
In this comprehensive guide we walk you through, step by step, how to realistically assess the return on investment of a solar system. You will learn which key figures truly matter, what a concrete sample calculation looks like, and which strategies you can use to maximise the profitability of your system. You can also use our PV Planner to run a personalised calculation for your own roof right away.
Why Solar PV Is Particularly Worthwhile in 2026
2026 offers an exceptionally favourable environment for photovoltaic investors. Several developments are working in favour of solar system operators:
Falling Module Prices with Increasing Efficiency
The price of solar modules has fallen continuously over recent years. While a turnkey system cost more than 2,000 euros per kilowatt-peak (kWp) a decade ago, costs in 2026 range between 1,100 and 1,500 euros per kWp depending on system size and module type. At the same time, the efficiency of modern modules has improved significantly, meaning that more electricity can be generated from the same roof area today than in the past.
High Electricity Prices as a Return Driver
The electricity price for new customers at the start of 2026 stands at around 27 cents per kilowatt-hour (kWh) gross. Existing customers on older tariffs are sometimes paying considerably more. Given geopolitical uncertainties — such as the situation in the Middle East — energy prices can rise again at any time. Every kilowatt-hour you generate and consume yourself saves you the current purchase price. This makes so-called self-consumption the most important lever for your system's profitability.
Tax Advantages
Since 2023, VAT on solar systems up to 30 kWp for residential buildings has been eliminated. In addition, income from grid feed-in is free of income tax for systems up to 30 kWp. These tax reliefs considerably improve the return on a PV system.
The Most Important Factors Affecting Profitability
To calculate solar PV profitability, you need to understand several influencing factors. The following variables largely determine whether — and how quickly — your investment pays off.
System Size and Investment Costs
The size of your system influences both the total cost and the unit price per kWp. Larger systems are generally cheaper per kWp because fixed costs such as installation and the inverter are spread across more modules.
| System Size | Cost per kWp | Total Cost (approx.) | Annual Yield (approx.) |
|---|---|---|---|
| 5 kWp | 1,400 - 1,500 EUR | 7,000 - 7,500 EUR | 4,750 - 5,250 kWh |
| 8 kWp | 1,250 - 1,400 EUR | 10,000 - 11,200 EUR | 7,600 - 8,400 kWh |
| 10 kWp | 1,200 - 1,350 EUR | 12,000 - 13,500 EUR | 9,500 - 10,500 kWh |
| 15 kWp | 1,100 - 1,300 EUR | 16,500 - 19,500 EUR | 14,250 - 15,750 kWh |
Yields are based on an average location in Germany with approximately 950 to 1,050 kWh of yield per kWp per year.
Self-Consumption: The Most Important Lever
The self-consumption rate indicates what percentage of your generated solar electricity you use directly yourself. The higher this proportion, the more profitable your system becomes — because electricity you use yourself saves you the full electricity price, whereas electricity fed into the grid earns only the significantly lower feed-in tariff.
Typical self-consumption rates without a battery storage unit are 25 to 35 percent. With a battery, this figure can be increased to 60 to 80 percent. Whether a battery storage unit is financially worthwhile depends, however, on storage costs and your individual consumption profile.
Feed-In Tariff
The feed-in tariff under the Renewable Energy Sources Act (EEG — Erneuerbare-Energien-Gesetz) is guaranteed for 20 years plus the year of commissioning. For 2026, it stands at approximately 8.0 cents per kWh for systems up to 10 kWp. A slightly lower rate applies to the portion of a system above 10 kWp.
The feed-in tariff alone no longer makes a system profitable today. Its significance lies rather in remunerating the surplus electricity that cannot be consumed on-site.
Electricity Price Trends
The future trajectory of electricity prices is a crucial but uncertain factor. Conservative scenarios assume an annual increase of 2 to 3 percent. This means: the longer your system runs, the more valuable every self-generated kilowatt-hour becomes.
Calculating Payback Period: How to Proceed
The payback period tells you how many years it will take for your system to recoup its investment costs. After that point, it produces essentially free electricity. Here is how to calculate the payback:
Step 1: Determine Annual Income and Savings
Your system's annual returns consist of two components:
- Savings from self-consumption = self-consumed kWh x electricity price in EUR/kWh
- Income from grid feed-in = kWh fed into grid x feed-in tariff in EUR/kWh
Step 2: Account for Annual Costs
Ongoing costs of a PV system include:
- Insurance: approx. 50 - 100 EUR per year
- Maintenance and cleaning: approx. 100 - 200 EUR per year
- Reserve for inverter replacement: approx. 50 - 100 EUR per year (an inverter typically lasts 12 to 15 years)
- Meter fee where applicable: approx. 30 - 50 EUR per year
Step 3: Calculate Payback
The simplified formula is:
Payback period = Investment costs / (Annual income + Savings - Annual costs)
Sample Calculation: 10 kWp System on a Detached House
Let us look at a concrete example to illustrate how to calculate solar PV profitability. We assume a typical detached house with an annual electricity consumption of 4,500 kWh.
Basic Parameters
| Parameter | Value |
|---|---|
| System size | 10 kWp |
| Investment costs (net) | 12,500 EUR |
| Annual yield | 10,000 kWh |
| Self-consumption rate (without battery) | 30 % |
| Self-consumption | 3,000 kWh |
| Grid feed-in | 7,000 kWh |
| Electricity price (new customers, early 2026) | 0.27 EUR/kWh |
| Feed-in tariff | 0.08 EUR/kWh |
Annual Returns
| Item | Calculation | Amount |
|---|---|---|
| Savings from self-consumption | 3,000 kWh x 0.27 EUR | 810 EUR |
| Feed-in tariff income | 7,000 kWh x 0.08 EUR | 560 EUR |
| Total annual return | 1,370 EUR | |
| Annual running costs | Insurance, maintenance, reserves | -250 EUR |
| Net annual return | 1,120 EUR |
Payback and Return on Investment
| Key Figure | Value |
|---|---|
| Payback period | approx. 11 years |
| Total return over 25 years (without electricity price increase) | approx. 28,000 EUR |
| Total return over 25 years (with 3% annual electricity price increase) | approx. 37,000 EUR |
| Return on investment (25 years) | approx. 4 - 6 % p.a. |
This calculation shows: at current new-customer electricity prices, the system pays for itself in around 11 years. Should electricity prices rise again — which is quite possible given geopolitical developments — the payback period shortens accordingly. Over the remaining 14 to 19 years of the system's service life, it generates a clear profit. Would you like to run a personalised calculation for your own situation? Our PV Planner delivers a detailed analysis in just a few minutes.
Variant with Battery Storage
A battery storage unit with a capacity of 10 kWh costs approximately 5,000 to 7,000 euros extra in 2026. This raises the self-consumption rate to around 70 percent.
| Item | Without Battery | With Battery (10 kWh) |
|---|---|---|
| Investment costs | 12,500 EUR | 18,500 EUR |
| Self-consumption | 3,000 kWh (30 %) | 7,000 kWh (70 %) |
| Grid feed-in | 7,000 kWh | 3,000 kWh |
| Savings from self-consumption | 1,140 EUR | 2,660 EUR |
| Feed-in tariff income | 560 EUR | 240 EUR |
| Total annual return | 1,700 EUR | 2,900 EUR |
| Net annual return | 1,450 EUR | 2,600 EUR |
| Payback period | approx. 8.6 years | approx. 7.1 years |
In this example, the battery significantly shortens the payback period because the savings from higher self-consumption outweigh the additional costs. This is especially true when electricity prices are high.
7 Tips to Maximise the Profitability of Your PV System
1. Optimise Self-Consumption
Shift energy-intensive appliances such as washing machines, dishwashers and tumble dryers to the sunniest hours of the day. Smart timers or home automation systems can help with this.
2. Choose the Right System Size
Do not size your system too small. Even if you cannot consume all the electricity yourself today, a larger system often pays off through lower unit costs and the option to add a battery, a heat pump or an electric car in the future.
3. Use Battery Storage Strategically
A battery storage unit is most worthwhile when your electricity consumption in the evenings and at night is high. The optimal storage size is generally 1 to 1.5 kWh per kWp of system output.
4. Combine a Heat Pump with PV
The combination of photovoltaics and a heat pump is particularly economical. The heat pump can make use of surplus solar electricity, substantially increasing self-consumption.
5. Charge an Electric Vehicle with Solar Power
If you own or are planning to buy an electric vehicle, you can significantly increase your self-consumption. A wallbox with PV surplus charging ensures that your car is charged preferentially with free solar electricity.
6. Compare Multiple Quotes
Obtain at least three quotes from different installers. Price differences can be considerable and directly affect the payback period.
7. Check Roof Orientation and Shading
A south-facing orientation with a tilt of 30 to 35 degrees delivers the highest annual yield. East-west systems can also be economically viable, however, as they increase self-consumption by generating electricity over a longer period of the day. Use our PV Planner to simulate the expected yield for your specific roof situation.
Frequently Asked Questions
How long does it take for a photovoltaic system to pay for itself?
The payback period of a photovoltaic system in 2026 is typically between 7 and 11 years. The exact timeframe depends on system size, self-consumption rate, local electricity price and installation costs. After the payback period, the system produces virtually free electricity for the remainder of its service life of 25 to 30 years. You can obtain a personalised calculation using our PV Planner.
Is a battery storage unit financially worthwhile?
A battery storage unit can improve the profitability of a PV system by significantly increasing the self-consumption rate. Whether the additional investment is worthwhile depends on the electricity price, consumption profile and storage costs. At electricity prices of 27 cents per kWh or more, and with high evening and night-time consumption, a battery can make economic sense — especially if electricity prices rise again in the future. The payback period of the battery alone is typically 8 to 12 years.
What ongoing costs does a PV system incur?
The annual operating costs of a photovoltaic system are manageable. Budget for approximately 200 to 400 euros per year for insurance, maintenance, cleaning and reserves for inverter replacement. For a 10 kWp system, this equates to roughly 1.5 to 3 percent of the investment costs — modest compared to annual returns of 1,500 to 2,500 euros.
How does roof orientation affect profitability?
A south-facing orientation with a 30 to 35 degree tilt delivers the highest annual yield. South-east or south-west orientations still achieve around 95 percent of the maximum yield. Even purely east- or west-facing roofs achieve 80 to 85 percent and can be economically viable, as they supply more electricity in the morning and evening, which benefits self-consumption. North-facing roofs are generally not recommended.
Does profitability increase as electricity prices rise?
Yes, rising electricity prices considerably increase the profitability of a PV system, because the value of self-consumed electricity rises directly in line with the electricity price. If the electricity price rises, for example, from 27 to 35 cents per kWh, annual savings on 3,000 kWh of self-consumption increase by 240 euros. The feed-in tariff, by contrast, remains constant. A PV system therefore acts as a hedge against rising energy costs.
Conclusion: Solar PV Is a Worthwhile Investment in 2026
The calculation makes it clear: a photovoltaic system in 2026 is a financially attractive investment. With payback periods of under ten years, a return of 5 to 7 percent and the prospect of rising electricity prices, solar power offers a solid financial investment with added ecological value.
The key takeaways at a glance:
- The payback period for most systems is under ten years
- Self-consumption is the strongest lever for profitability
- Tax advantages improve the return further
- Battery storage can increase profitability still further
- Rising electricity prices make PV more valuable with every passing year
Calculate Your Individual PV Profitability Now
Every property is different, and general sample calculations are no substitute for a personalised analysis. With our PV Planner you can calculate the profitability of a solar system for your specific roof in just a few minutes. Simply enter your roof area, orientation and electricity consumption to receive a detailed yield analysis with payback calculation.