Trying to Create a Summary Report

I have a number of worksheets where I have extensive data on Energy Generation. In each worksheet I have added a column (AA) where the data for the day is totalled (I do this manually too and would like to be able to automate it but that is not my biggest issue right now:-)).

I want to take the total power generation by technology type for each day and place it in a summary sheet. In the attached spreadsheet I have done this manually (summary sheet) but it is very time consuming, especially since I have to do this for many many more months of data.
Could someone please help me understand what would be an easier way to summarise the data?