Solar PV tailored to you / Calculator
Move consumption, roof orientation and battery size and see how much the system generates, how much of it you really use, and what that saves. Already have a quote? Enter its price and get the payback.
We do not publish prices: without a surveyed roof the number is useless. If you already have a quote, enter it here and the calculator works out the payback from it.
Solar PV only earns on the electricity you actually use in the building. A kilowatt-hour you keep saves the full retail price including distribution and levies; a kilowatt-hour exported to the grid sells for a fraction of it. That is why capacity is designed around how much electricity flows through the house and at what time of day, not around how much roof there is.
The calculator starts from the annual total because everyone can find it on their bill. The real design then uses quarter-hourly data from the distribution company, which also shows the shape of the day. Two houses with the same annual consumption can need very different battery sizes.
A payback under eight years is worth having the design checked. Over fifteen usually means the system is sized above the actual consumption, or the quote includes items the building does not need.
Payback is the installation price divided by the annual saving, so both sides matter. What decides it is the share of electricity you use on site and your full price per kWh including distribution. A house with a heat pump or an electric car gets close to eight years; a low-consumption house without a battery is usually above twelve. Enter the price from a quote you already have and the calculator works out your own figure.
In Czech conditions one kilowatt of capacity generates roughly 900 to 1,050 kWh a year, so 4,000 kWh corresponds to about 4 kWp of panels. That alone does not mean consumption is covered: without a battery you use around thirty percent of generation directly. Storage capacity is therefore designed together with panel capacity.
Because without a surveyed roof it is a number that helps nobody. The price depends on the roof covering and mounting, cable run lengths, the state of the distribution board, the number of phases, battery capacity and the type of grid connection. We quote after a site survey, which is free and non-binding. If you already have a quote, the calculator works out its payback.
A saved kilowatt-hour is worth your full retail price including distribution; an exported one only the export price, which is far lower. A battery therefore pays where it moves generation into the evening peak. Only up to a point, though: as the calculator shows, every further five kilowatt-hours of capacity adds less coverage than the previous one.
We only need your annual consumption from the bill and a few details about the roof. We will contact you within 24 hours, ask for further details and arrange a technical inspection. The design and inspection are free of charge and non-binding.
Call on working days; we will go through it together in ten minutes.
775 654 443