decize
Worth it or not. Computed hour by hour, on your own consumption.
Solar panels, a battery, a heat pump, an electric car: everyone says they pay off, nobody proves it on your numbers. decize crosses your real load curve with the expected output of your roof and with the hourly value of electricity, and tells you what it is actually worth – and how much that changes if things turn out differently from what you hope.
Why it is needed
When you consume matters, not how much
With the same system and the same bill, a house that is empty from 8 to 6 and a house where someone works remotely get different results. It is the one variable that really decides, and the one online calculators never ask about.
It starts from your real data
From your bills, or better still from the quarter-hourly load curve your grid operator already records and that you can download. No average profile, no typical family: yours.
The choices interact
A heat pump moves consumption from gas to electricity in winter, exactly when solar produces least. An electric car adds load you can shift to the night, or to midday. Assessing them separately leads to wrong decisions.
A range, not a number
Nobody knows the future. decize computes across several consumption scenarios and gives you the spread: how you live in the house can matter more than which technology you pick.
8'760 hours, no optimiser
decize does not search for an optimal solution in an abstract space: it walks through the hours of the year one by one and shows what happens. In each hour it compares what you produce with what you consume, decides what goes into the battery and what goes to the grid, and values each flow at the price it deserves. It is a calculation you can follow by hand – which is why the result can be challenged, and therefore defended.
- Self-consumption, charge, discharge, grid import and export, hour by hour
- Every flow valued at the right price: savings, feed-in tariff, guaranteed minimum
- A few configurations compared, not an optimum nobody can verify
- Validated on a real case: same result as the spreadsheet it grew out of, cell by cell
Two doors, one engine
decize starts from the home, but people weighing an electric car are usually weighing nothing else. That is why the mobility module works on its own – and why the two talk to each other when you need both.
decize
Home: solar, storage, heat pump
Sizes the system on your roof and on the way you actually consume. It returns a map: the value of every combination of capacity and storage, so you can see where the optimum sits and how steep it is around it.
- Hourly output for your roof from PVGIS, the European Commission's Joint Research Centre service
- Battery simulated hour by hour, with charge and discharge efficiencies
- Feed-in revenue, hourly zonal prices, tax credit capped by your own tax capacity
- The spread across scenarios, not a single figure
decize mobility
Whether an electric car is worth it for you
It starts from how you actually travel: how many kilometres, which recurring trips, what you use today for each of them. It compares against real-world consumption reported by drivers, not homologation figures.
- Your own typical journeys, not a national average
- Compared with the car you have, not a generic one
- Where you charge: whether you have a garage, how wide it is, what power you can get
- And if you also have solar, how much charging fits inside it
The installer’s quote promises savings, but computes them on a consumption profile that is not yours. Online calculators ask for three numbers and return one. And whoever builds their own spreadsheet discovers it works only as long as they are the one holding it.
The same thing is missing every time: nobody crosses your real load curve with the real output of a system and with the hourly value of electricity. And that is exactly where an investment is decided.
decize grew out of a real case – one house, a full year of metered consumption, a quote on the table – and out of finding that careful numbers say different things from what you expect. That at today’s prices, without a time-of-use tariff, a battery often removes value rather than adding it. That the best size for a system is set not by the roof but by the tax capacity of whoever installs it. These are not opinions: they are the output of the same calculation, repeated across every combination.
They are also the kind of answer nobody has an interest in giving you, if they are selling. That is why decize exists.
Got a house and a doubt?
If you are weighing up a solar system, a heat pump or an electric car and you want the numbers run by someone who is not selling you anything, write to us: we are looking for real houses to run decize on before launch.