Subsidies for Solar Systems: Photovoltaics & Solar Thermal Explained Simply

Solar systems are one of the most popular measures to reduce energy costs and live more sustainably. To ensure that the investment pays off more quickly, there are numerous state funding programs for photovoltaic and solar thermal systems in Germany. In this article, you will learn about the funding options available, who is eligible, and how high the subsidies can be.

At first glance, the funding landscape seems confusing: federal, state, and municipal governments offer programs that sometimes run in parallel, with different conditions. However, taking a few hours to research before purchasing can significantly improve the economic viability of your system – and avoid costly formal errors such as applying too late. This guide sorts out the most important programs and shows what matters when applying.

Difference between Photovoltaics and Solar Thermal

Before we look at the funding, it is important to know the differences – because while both technologies use the sun, they do so in completely different ways and are funded accordingly. Photovoltaic modules generate electricity, which you can consume yourself, store in batteries, or feed into the public grid. Solar thermal collectors, on the other hand, heat a transfer fluid that transfers its heat via a storage tank to domestic hot water or the heating circuit.

This results in different areas of application: Photovoltaics reduce your electricity bill and make you more independent of the energy supplier, while solar thermal directly relieves the heating system – particularly noticeable when heating domestic hot water in the summer half-year. At a glance:

• Photovoltaics (PV): Converts sunlight directly into electricity. Ideal for self-sufficiency in energy.
• Solar Thermal: Uses solar energy to heat water or support heating.

Both systems contribute to energy efficiency and are state-funded – practical saving tips can be found in the guide Energy Efficiency in Home Technology.

Which solar systems are funded?

A common misconception is that only complete new installations are funded. In fact, many programs also support the expansion and modernization of existing systems – for example, replacing old collectors, retrofitting a storage unit, or integrating the solar system into a new heating system. Especially with older systems, it is worth looking at the current conditions, because modern components work much more efficiently.

Combination solutions are particularly attractive: those who couple the solar system with a heat pump or surface heating optimize the use of solar energy throughout the year and thus often meet the requirements for additional bonuses. Both new systems and the modernization of existing systems are funded. These include:

• Photovoltaic systems for self-consumption or feeding into the grid
• Solar thermal systems for hot water preparation and heating support
• Combinations with heat pumps or underfloor heating for maximum efficiency

Suitable components – from collectors to solar controllers – can be found in our solar technology range.

What funding programs are available?

Funding in Germany is distributed on three levels: the federal government with BAFA and KfW, the federal states with their own programs, and cities and municipalities with local subsidies. These levels can often be combined, significantly increasing the total funding. The most important points of contact at a glance:

1. BAFA Funding

The Federal Office for Economic Affairs and Export Control (BAFA) primarily supports solar thermal systems. Depending on the system size, subsidies of several thousand euros are possible. The subsidy is paid out directly and does not have to be repaid – which makes BAFA funding particularly predictable.

2. KfW Funding

The KfW Bank offers favorable loans and subsidies for photovoltaic systems and battery storage. The program for combining PV systems and electricity storage is particularly interesting. The advantage of the credit model: you protect your liquidity and finance the system with the saved electricity costs.

3. Regional Funding

Many federal states, cities, and municipalities offer additional subsidies. Therefore, it is worth inquiring with the local energy agency. These programs are often less well-known and are exhausted more quickly – those who inquire early secure the best chances.

Funding Amount and Requirements

How much money ultimately flows depends on several factors: the type of system, its size, the location, and the respective program. Therefore, there is no flat figure – but there are typical orders of magnitude that you can use as a guide. It is important to compare the programs before making a purchase decision, as the conditions sometimes differ significantly.

Typical funding:

• Photovoltaics: Subsidies up to 20% of investment costs
• Solar thermal: Subsidies up to 30% of costs, even more for large systems
• Combination systems: additional bonuses possible

Regardless of the program, almost the same basic rules apply everywhere. Knowing them avoids the most common reasons for rejection:

• The system must be installed by a specialized company.
• Applications must be submitted before the start of installation.
• Proof of efficiency and use is required.

The second point is the most critical: an already signed contract or even a commenced assembly usually leads to a complete loss of funding for most programs. There are also attractive subsidies for heating system replacement – more on this in the article Heat Pump Funding 2026.

FAQ on Solar Funding

Is there still funding for solar systems in 2025?

Yes, the federal government continues to focus on expanding renewable energies. Funding will still be available in 2025 through BAFA, KfW, and regional programs. Since conditions can change, it is worth checking the current program conditions before applying.

Can I combine photovoltaics and solar thermal?

Yes, the combination is possible and often particularly efficient: the PV system covers the electricity demand, and solar thermal relieves the heating system. In addition, there are often additional funding bonuses for this.

How do I apply for funding?

Funding applications must be submitted directly to BAFA or KfW – usually online. We recommend speaking with a specialized company beforehand to submit the documents correctly. Those who optimize the heating system at the same time benefit twice – see Hydraulic Balancing 2026: Obligation, Costs, and KfW Funding.

Conclusion: Use solar funding and benefit twice

Those who invest in solar systems not only save energy costs but also receive attractive subsidies from the state. Whether photovoltaics or solar thermal – the funding programs from BAFA, KfW, and regional providers make starting particularly worthwhile. Three things are crucial for success: applying before installation begins, execution by a specialized company, and comparing several programs before making a purchase decision. Those who consider these points get the maximum economic benefit from their system. You can find the right technology for your home in the heating and solar technology selection of Wohnungstechnik.de.