Epic: Multi-year investment feature

[datejada]

Description
The multi-year investments in SpineOpt are based on the proposal in discussion #476

Steps
Please create an independent issue for each step (and even consider splitting this one if needed). The goal is that each issue can be merged with passing the existing and new tests to continue to the next one. Create a new branch from the master for each step to merge individually.

• Create new parameters for the economic representation in the multi-year investments #909
• Change the variable history in the model to avoid having unnecessary values in memory #910
• Change temporal structure for investment and operation blocks in multi-year investments #1041
• Test vintage investment through input data (see last Maren's comment in Discussion SpineOpt: Multi-period investments #476)
• Update objective function to use economic parameters #1050
• Export economic parameter results #1051
• Include unit_discounted_duration, connection_discounted_duration, storage_discounted_duration in the output #1057
• Create the new variables and constraints for the multi-year investment for units (i.e., vintage) #911
• Create the new variables and constraints for the multi-year investment for storage (i.e., vintage) #976
• Create the new variables and constraints for the multi-year investment for connections (i.e., vintage) #977
• Add the new variables to the current code to link the vintage variables to the available units #912
• Update on the technical lifetime of a unit/storage/connection constraint #689
• Update the documentation (e.g., formulation and features) #913
• Create a Multi-Year Investment tutorial without using economic representation parameters #914
• Create a Multi-Year Investment tutorial focusing on how to use economic representation parameters #1070

Additional context
Related PR ##448, and Discussion #476

[manuelma]

Here it would be nice to have the story behind the change - the full design. What's the current situation, what is missing and what we want to include/change then. This would help us understand the changes in the code much better.

Maybe #448 and #476 have the information but it would be nice to have a summary directly here, or at least a link to a single post or document containing the design.