Check solar system cost (quote checker)
The calculator for the moment three quotes sit on the table: it checks each position against the current market band and flags outliers high and low. On top it translates the quote price into euros per kilowatt-hour of annual yield at your location — only that number makes quotes for different sizes and roof orientations comparable, because what you buy is the kilowatt-hour, not the kilowatt. A conspicuously low price is as much a warning sign as a high one.
The formulas behind the calculator
Every number above can be recomputed: the full calculation path, all assumptions and the data source with retrieval date — plus cross-validation against independent references. Disclosed, not claimed.
An estimate based on the stated assumptions. The final design must be checked by a qualified professional against the rules that apply where you are.
| Step | Formula | Value | Provenance |
|---|---|---|---|
| Market band PV system | kWp * Band(EUR/kWp) | 15,000 EUR | assumed |
| Market band storage | kWh * Band(EUR/kWh) | 5,600 EUR | assumed |
| Operating cost per year | Angebot_PV * 1-2 %/a | 260 EUR/a | assumed |
- Formula
Quote per unit = position / amount · compared against market band [min, max] per position · operating cost 1–2%/a of investment- Valid for
- Turnkey rooftop systems in Germany (band surveyed for 10–100 kWp, net = gross thanks to 0% VAT), LFP home storage installed; band dates shown in the result.
- Not covered
- Special mounting (flat-roof racking, facade, in-roof), special scaffolding costs, grid-connection/meter-cabinet costs of the DSO, regional spread, per-component prices of the quote (modules/inverter separately) — spot-market module prices are not end-customer prices and are shown for context only.
Frequently asked questions
What does a solar system really cost in 2026?
As a market band, not a point value: turnkey rooftop systems in Germany sit around €1,000–1,500 per kWp net in 2026 (BSW price-index class 10–100 kWp; spring 2026 average: €1,015/kWp — a historic low). A 10 kWp system thus costs roughly €10,000–15,000. Home storage adds €350–700 per kWh installed. Every figure in the calculator carries its survey date and is reviewed quarterly — two-year-old prices are worthless at the current price dynamics.
How does the quote checker work?
You enter the two core positions of your quote — PV system turnkey and storage installed. The calculator divides by kWp or kWh and lays the result on the market band: in the example the PV position sits within the band at €1,300/kWp, but the storage at €800/kWh is 14% above it. Flagging goes both ways — including unusually low prices, because that is where scaffolding, electrical installation or commissioning most often go missing from the scope.
Why is a too-low price a warning sign?
Because the band reflects prices actually paid for complete installations: whoever offers far below it usually leaves something out — scaffolding, meter-cabinet adaptation, grid registration, commissioning protocol — or installs remainder stock without a solid warranty. Both cost you more later than the price difference saved. That is why the calculator responds to undercutting with a concrete checklist instead of praise.
Why do module prices show €0.10–0.16/Wp while systems cost €1,000–1,500/kWp?
Because the module spot price (pvXchange, July 2026: mainstream €0.135/Wp) covers only the trade purchase. The end-customer price per kWp includes the inverter, racking, cables, scaffolding, two trades of labour, registration and margin — per Fraunhofer ISE, modules account for only about one fifth of the investment. pvXchange itself states a factor of 8–15 between spot price and turnkey system. Hence the calculator checks complete positions and shows the spot price for context only.
Does the band apply to small systems below 10 kWp?
Only with limits: the band is surveyed for 10–100 kWp. At 4–6 kWp, scaffolding, travel and registration spread across fewer kilowatts — such systems often exceed €1,500/kWp without being overpriced. The calculator flags this explicitly for small systems and does not treat exceeding the band as an alarm there.
Are there running costs on top of the system price?
Yes, and the calculator quantifies them: 1–2% of the investment per year (Fraunhofer ISE) for insurance, maintenance, meter fees and reserves — €130–260/year on a €13,000 quote. Tax helps twice in Germany: 0% VAT on delivery and installation (§ 12 (3) UStG, net = gross) and income-tax-free operation up to 30 kWp. For the payback maths, the hand-off link continues into the payback calculator.
How do I tell whether a solar quote is too expensive?
By the price per kWp against the market band. The calculator sets the PV and storage lines of your quote against the current bands from the maintained price dataset: 1,000 to 1,500 €/kWp turnkey and 350 to 700 €/kWh installed (as of 07/2026). It flags outliers upwards AND downwards — a conspicuously cheap quote is not good news but a reason to work through the checklist.
What does the quoted price mean in cents per kilowatt-hour?
Only that figure makes quotes of different sizes comparable. The calculator divides the quote total by the annual yield the system actually delivers at your location. Two quotes with the same price per kWp can differ markedly here if roof pitch, orientation or location differ — the kilowatt-hour is what you buy, not the kilowatt.
Why is a very cheap quote suspicious?
Because on turnkey systems the modules account for only about a fifth of the cost. Anyone well below the market band is not saving on modules but on items that often do not appear in the quote at all: scaffolding, electrical work, meter cabinet, commissioning and registration. So when the price falls short the calculator issues a checklist rather than praise.
Why are systems under 10 kWp more expensive per kWp?
Because a substantial part of the cost does not scale with system size: scaffolding, travel, meter cabinet, registration and commissioning arise almost regardless of module count. The calculator reports this as its own size-class note, so that a higher per-kWp price on a small system is not misread as an overpriced quote.
How current are the market prices in the calculator?
The dataset carries its collection date and an expiry: as of 3 August 2026, valid until 3 November 2026. After that the build turns red until the bands are re-collected — deliberately so, because stale price bands are worse than none. Module spot prices sit alongside for orientation only: between the module price and the turnkey system price lies a factor of 8 to 15.