This page provides information about the spreadsheet model generator at http://dcmf.co.uk/models/.
This online system creates spreadsheets on demand that seek to reproduce and experiment with parts of the charging methodologies used for electricity distribution in England, Wales and Scotland.
You can get workbooks from this site that perform the same calculations as the distributors' own pricing models, subject to any errors, and workbooks that implement different rules, corresponding to possible variations in the methodologies.
The system delivers fully working spreadsheets, with formulas that you can use, read and modify with Microsoft Excel or compatible software.
The models come in uncalculated form: they only contain the input data and formulas, not the results of the calculations.
In order to enable all the formulas in the workbook to work, you might need to save the file out of your web browser, open it in a suitable application (such as Microsoft Excel) and in some cases force a recalculatin and/or authorise the app to make changes to the workbook.
Changing input data is straighforward. The results will update automatically in response to changes in input data; there are no macros or anything like that.
If you want to make changes to the formulas, you will need to unprotect the sheets. There is no password.
The system gives a revision number (something like r5678) to each set of rules that it encounters. Any change to the rules or to the underlying computer code will cause the revision number to change. Two models with the same revision number should be identical other than in their input data when downloaded from this website. (But obviously I cannot vouch for what changes might be made afterwards.)
The source code and data used to create these models are on GitHub.
Models are created on demand. If the server is busy then you might have to wait a minute or two before the model is ready to download to your machine. All being well, your browser will wait automatically download the model as soon as it is ready.