Since the old thread has become unstable and produced many answer loops, I start here new.

Input: “Demand — battery, cars, grid targets”
Make grid targets an extra chapter as “Grid targets and prices”.

Price model for electricity:
Summer (April-September), Winter (October to March) half-year,
Workday, weekend,
import, export
high, medium, low
For example: low spot market prices could be 2 Cent.
But at export 2 - 2 handling fee - 1 Ausgleichsenergiebeitrag = -1
But at import: 2 + 2 handling free + 10 grid fee = 14.
Makes a total of 24 fields.

Peak grid demand per month per kW price.
Burgenland for example € 76 / 12 = € 6.33.
Since some month are at Austrian spot market prices harsh differences between workday and weekend.
This makes the point in the form “Export from 09:00 to 15:00 WT” obsolet.
Just do not sell when the earning is negative.
Export at 0 Cent when not other possible, at last this makes the PV some degrees cooler.
Rule: export at 0 Cent only PV yield, not from the battery.
It makes for example possible:
summer low price workday: 3 weekend: -3.
It makes it possible to compare with no PV, no battery, and a fixed electricity tariff.
At Bugenland peak usage grid fees, the simulated bill for the taxi driver coming home for lunch will be extreme without a large battery.

Page 21: Energy -> Energy in kWh
Page 22 new to make: Energy by price.
Make here import, export, balance.
Grid fees by peak 15 minutes demand are added to the import in a month and show up in this way in the balance.

Handling of database errors with 0 yield for a day:
See it as a database error only when the sun reaches the horizon at noon. Not 10° above the horizon like now.
Old handling: skip the day.
New handling:
For the simulation: take the day with the lowest yield of this month from all years and use the data of this day for the simulation of the wrong 0 yield day.

New for the form: Select compare two stored object simulations.
It should show the objects folder.
In each object folder are all the pdf/json files earlier produced.
Now select two files for compare.
The comparison produces a PDF as an output file.
The naming convention:
foldername 1 filename 1 vs foldername 2 filename 2
Since the filename also contains a simulation name, this should produce useful file names.
For example:
GEMINI-60-house-with-garage 2026-10-04 1224 - Austria - Krems - 48.4 - 15.989 vs GEMINI-60-house-with-garage 2026-10-04 1254 - no garden fence - Austria - Krems - 48.4 - 15.989.pdf

For the compare PDF
List the configuration of both objects.
outline the differences.
So it is easy to see where both objects are the same and where are the differences.

After this follows from page 21 to the last page of the objects' statistics:
In the object's statistics, there are always 3 lines: maximum - average - minimum.
For each of these lines in the compare PDF:
One line values of objejct 1
One line values of object 2
One line the difference.
The difference is shown in green when it's better.
The difference is shown in red when it's worse.
Better or worse depends on context.
More export is better
More import is worse