Financing Solar Panels: KfW Loan, Bank Loan or Savings?

Financing solar panels is not a must: the cheapest PV system is one you pay for fully or partly from savings, because then there is no interest to pay. If savings aren’t enough, three routes are the most common: the KfW 270 development loan, a home-improvement or personal loan from your bank, or topping up your mortgage. As a guide, a 10 kWp system costs around €14,500–17,500 without storage and €22,200–26,700 with storage. Here you’ll learn which kind of financing suits you, what a loan really costs and in which order to handle the quote, the loan application and the order.

Request your free, no-obligation quote now: you can take our written fixed-price quote straight to your bank.

Financing solar panels: the key facts

Is financing solar panels worth it?

Whether it pays to finance solar panels depends mainly on three things: the interest rate, the term and the share of solar power you use yourself. Every kilowatt-hour from your own roof replaces expensive grid electricity, while the feed-in tariff for new systems up to 10 kWp has been only around 7.7 cents per kilowatt-hour since 1 August 2026. A system with high self-consumption therefore carries a loan much more easily than one that feeds most of its power into the grid.

A simple rule of thumb: interest is a cost that pushes the payback period further out. If you pay from savings, you give up the interest on a savings account, but that is usually lower than the interest on a loan. Partial financing, where you pay part yourself and finance only the rest, is therefore often the best compromise. How profitable a PV system is without any loan is shown on our page Is photovoltaics worth it?

Financing solar panels: what does a loan cost?

For this example we take a 10 kWp system with BYD battery storage for €24,000, i.e. in the middle of the price range above, financed in full. The interest rate is an assumption, because your bank sets it based on your creditworthiness. The payments are annuity payments without repayment-free years.

Against this stand the savings. In the Hannover region, a 10 kWp system produces around 9,100 kWh per year. If you use about 60 % of it yourself with a battery, that is around 5,460 kWh. At an assumed electricity price of 37 cents per kWh, you save around €2,020 a year, plus around €280 feed-in tariff for the remaining 3,640 kWh. Together that is about €2,300 per year, or around €190 per month.

The result: with a 15-year term and a good rate, the system almost pays for itself from the first year. With a 10-year term you pay a little extra for some years, but you are debt-free sooner and pay less interest. Once the loan is repaid, the full savings stay with you. These figures are a model, not an offer: electricity price, self-consumption and interest rate are assumptions, and we calculate your own figures in your quote.

Own savings: the cheapest financing

If you can pay for the system from savings, that is almost always the cheapest option: no interest, no credit check, no application and no time pressure from a loan approval. Just make sure you still have an emergency fund after the purchase. A PV system is a long-term investment that pays off over the years, not money you can withdraw at short notice.

Partial financing combines both advantages. If, for example, you pay for the PV system yourself and finance only the battery, the loan stays small and the term short. Because PV systems and storage on residential buildings are sold at 0 % VAT, you don’t have to finance any VAT either. Details are on our page about VAT on photovoltaic systems.

Financing solar panels with the KfW 270 loan

The KfW 270 loan «Renewable Energies – Standard» is a low-interest development loan, not a grant. Private individuals can use it if they feed part of their solar power into the grid. KfW treats this as a commercial activity, so you submit a commercial confirmation with your application. Up to 100 % of eligible costs can be financed, including planning and installation, and a battery as part of the same project. Whether retrofitting a battery alone to an existing system is also financed is best clarified with your bank using the current KfW information sheet.

Term, repayment-free years and interest rate

According to the KfW information sheet, the minimum term is 2 years, and up to 30 years are possible with up to 5 repayment-free years at the start. Depending on the variant, the rate is fixed for up to 20 years. Your bank sets the actual rate: it places you in one of KfW’s price classes based on creditworthiness and collateral, each with a maximum rate. You’ll find the current conditions on KfW’s programme page.

Apply before you place the order

You don’t apply directly to KfW but through a bank or savings bank of your choice, and you must do so before the project starts. In practice this means: get the quote first, then apply for the loan, and only sign the order after approval. Check early whether your bank offers the development loan for a system the size of a single-family home. If its rate is no better than a standard home-improvement loan, compare the two. More about the programme is in our article on KfW funding for photovoltaics.

Financing solar panels with a bank loan, mortgage or building savings

Home-improvement or personal loan

A personal loan is usually the fastest way to the money, and no land charge is needed. In return, interest is usually higher than with financing secured by a land charge. Some banks offer earmarked home-improvement or energy loans that can be cheaper than a free personal loan. Always compare the APR rather than the nominal rate, and ask about free special repayments.

Top up your mortgage or use a land charge

If you are building or your mortgage is still running, the PV system can often be included in the property financing. If a land charge registered in the land register has been freed up by repayment, a new loan can be secured with it. Loans secured this way usually have lower interest, but notary and land registry fees apply. Whether your roof is suitable for a system is explained in our guide to rooftop solar systems.

Building savings contract (Bausparvertrag)

A building savings contract that is ready for allocation can be suitable for a PV system: many building societies accept the system on your own home as a residential use. Check this with your building society beforehand.

Rent instead of buy?

Instead of financing, you can also rent or lease a solar system. You then pay a fixed monthly rate over a long contract, often around 20 years, with no purchase costs. The price: over the term you usually pay considerably more than when buying, the system often only becomes yours at the end or never, and you are tied to one provider for a long time. If you can get a loan, buying and financing is cheaper in most cases, because the system is yours once the loan is repaid and the full savings stay with you.

How you pay for your system with PVPro Solar

If you are financing solar panels, your bank or savings bank is responsible for the loan itself. We make sure it gets everything it needs for its decision, and that you don’t have to pay in advance.

A written fixed-price quote for your bank

After the free initial consultation with a roof analysis, you receive a written quote with a fixed-price guarantee, a list of all components and a yield forecast for your roof. Your bank can use it to assess the loan amount and profitability. We install modules from AIKO, JA Solar or Longi, inverters from Fronius, storage from BYD and mounting systems from K2 Systems, all named clearly in the quote.

30/70 payment model instead of prepayment

With us you pay 30 % when you place the order and 70 % only after installation. This fits loan financing well: you draw down the largest part only once the system is on your roof. Installation is carried out by our own certified installers, with no changing subcontractors.

A local example: Rethen

In Rethen we built a 10.23 kWp system with 24 JA Solar modules, a Fronius GEN24 Plus and a BYD HVS 10.2. The total investment was €21,400. Exactly these details, output, components and fixed price, are also in your quote.

Request your free, no-obligation quote now and take the fixed-price quote to your bank.

Funding and taxes: what lowers the loan amount

There is no federal grant for private PV systems or battery storage. Regionally things look better: in Hannover, Hemmingen, Laatzen, Langenhagen, Ronnenberg and Seelze, proKlima’s DachVollToll programme funds fully covered roofs on existing residential buildings with €100 per kWp, up to €2,000, while funds last. You must apply before placing the order. All regional programmes are on our page about solar funding in Hannover, and the national overview is in our guide Are there subsidies for solar panels in Germany?

Two tax rules help you: since 1 January 2023, a 0 % VAT rate applies to the supply and installation of PV systems and storage on residential buildings. And income from systems up to 30 kWp per residential or commercial unit is exempt from income tax (Section 3 No. 72 of the German Income Tax Act). The flip side: because the income is tax-free, you usually can’t deduct the loan interest either. More in our article on tax-free photovoltaic systems.

Financing solar panels: the right order of steps

1. Consultation and quote: we check your roof, plan the system and send you a written fixed-price quote with a yield forecast.
2. Sort out financing: take the quote to your bank, discuss KfW 270, a home-improvement loan or your mortgage, and compare the APR.
3. Submit applications: apply for the KfW loan and regional funding before placing the order.
4. Place the order: after approval, sign the order and pay 30 %.
5. Installation and registration: our installers fit the system, and we register it with the grid operator and in the Marktstammdatenregister. Then you pay the remaining 70 %.

When financing solar panels, mind the timing: according to the cabinet draft of the EEG 2027, systems commissioned by 31 December 2026 are to keep the fixed 20-year feed-in tariff. So allow for your bank’s processing time. The current status of the legislation is on our page about the EEG amendment.

Want to know what the loan amount would be for your roof? Call us on 0511 3360603, message us on WhatsApp or request your free quote now.

Frequently asked questions about financing solar panels

Note: This article gives a general overview (as of October 2026) and is not tax, legal or financing advice. Interest rates, electricity price and self-consumption in the worked example are assumptions.