Sub aggregation between records

An "Artist Impression" in this video (explaining the code below) how it could look like in Power Query with the data from an Excel file.

let
    Source = Excel.Workbook(File.Contents("C:\Users\Marcel\Documents\Forum bijdragen\Power BI Community\Subaggregation between values.xlsx"), null, true),
    Tabel1_Table = Source{[Item="Tabel1",Kind="Table"]}[Data],
    #"Changed Type" = Table.TransformColumnTypes(Tabel1_Table,{{"Timestamp", type datetime}, {"Wood", Int64.Type}, {"Fuel", Int64.Type}}),
    #"Added Index" = Table.AddIndexColumn(#"Changed Type", "Index", 0, 1),
    #"Added Custom" = Table.AddColumn(#"Added Index", "StartIndex", each if [Wood] = null then [Index] else null, Int64.Type),
    #"Filled Up" = Table.FillUp(#"Added Custom",{"StartIndex"}),
    #"Added Custom1" = Table.AddColumn(#"Filled Up", "EndIndex+1", each if [Wood] <> null then [Index] else null),
    #"Filled Up1" = Table.FillUp(#"Added Custom1",{"EndIndex+1"}),
    #"Added Index1" = Table.AddIndexColumn(#"Filled Up1", "Index.1", 1, 1),
    #"Merged Queries" = Table.NestedJoin(#"Added Index1",{"Index.1"},#"Added Index1",{"Index"},"NewColumn",JoinKind.LeftOuter),
    #"Removed Columns" = Table.RemoveColumns(#"Merged Queries",{"Index", "EndIndex+1", "Index.1"}),
    #"Expanded NewColumn" = Table.ExpandTableColumn(#"Removed Columns", "NewColumn", {"EndIndex+1"}, {"EndIndex+1"}),
    #"Inserted Subtraction" = Table.AddColumn(#"Expanded NewColumn", "Count", each [#"EndIndex+1"] - [StartIndex], type number),
    #"Added Custom2" = Table.AddColumn(#"Inserted Subtraction", "TotalFuel", each if [Wood] <> null and [StartIndex] <> null then List.Sum(List.Range(#"Removed Columns"[Fuel],[StartIndex],[Count])) else null),
    #"Removed Columns1" = Table.RemoveColumns(#"Added Custom2",{"StartIndex", "EndIndex+1", "Count"})
in
    #"Removed Columns1"