Energy Reading Billing App / Excel

We sell electricity to our customers from solar plants and currently we do billing manually on excel (attached).

We want to make the billing database as well as bill printing by a software where all the data is stored for all the customers along with their previous billings. I am attaching excel file for reference to understand what all data is there.
The final result should be web based, where by all data may be stored on our web space and software also runs online so that it may be accessed from anywhere. or atleast if the software is computer based, database should be online so that it may be accessed universally.

Or an advanced excel may be made in lines with the attached format which is currently in use.
Output files are given for example. Format needs to be upgraded based on your creativity.