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Your defaults

These decide what the site assumes until you say otherwise: currency, units, how the panel database sorts, and what the calculator starts from.

Saved only in this browser's local storage - no account, nothing sent to a server, no save button. Changes apply immediately.

01

Simulation assumptions

Open the calculator
Yield and tariff

Roughly 900 to 1,400 across Europe and 1,200 to 1,800 across the United States, depending on latitude, tilt and shading. Look yours up with PVGIS or read the guide to using it.

What these change

The yield figure scales every energy and savings number on the site. The tariff and its inflation only matter where money is involved: the lifetime cost comparison, the payback estimate and the cost per kilowatt-hour in a comparison report.

None of them changes a panel's specification or its position in a ranking. Rankings are computed from datasheet figures alone, so no setting here can move one.

Compare two panels
02

Units and currency

Measurement system

Applies to dimensions, weight and temperature everywhere they are printed. Electrical figures stay in volts, amperes and watts in both systems.

Currency

This is also the currency the shop offers table and the price section on a panel page open in - the "Prices in" switcher on either page starts here, and changing it there changes it here. Left on the shop's own, every price is the figure the shop printed. Pick a currency and each one is converted at today's ECB rate and marked ≈. Nothing here is a quote: check the seller's own page before acting on a figure.

03

Lists and tables

Open the database
Default sort
Prices and comparisons

Pre-selects the market filter wherever offers are listed. Offers are scraped from public retailer pages. A shop that pays us a commission has its links marked affiliate, and that never changes the order.

04

Where this is stored

Local storage, and nothing else
  • Held in your browser's local storage, under a single key.
  • Never sent to a server, never attached to a request.
  • No account, no sign-up, no advertising or tracking cookies.
  • Specific to this browser on this device. Clearing site data clears these too.
Start over

Puts every setting on this page back to the value a first-time visitor gets: 1,200 kWh/kWp, 0.15 per kWh, no inflation, shop's own currency, metric, sorted by rated power, 20 rows a page.