Adding ramping costs. Upward and downward ramps separated into different tiers (or 'slacks') with different costs.

Replaced q_fixedGenCap2U with q_constrainedCapMultiUnit, which enables different decommissioning and replacement decisions in addition to fixed investment ratios. Removed unnecessary parameters and divided p_groupPolicy into p_groupPolicy and p_groupPolicy3D. Renamed also the linking sets related to groups, e.g. gnu_group --> gnuGroup.

Added fixed operation and maintenance costs for investment options
Adding a new parameter unitOutputCapacityTotal to avoid division by zero
Added unit investment result parameter
Removed equation q_fixedGenCap1U
Added default value calculation for reserves update frequency
Moved tCounter update outside ms loop in 3c_periodicLoop.gms
Updated the limits of v_invest_LP and v_invest_MIP (no more maxGenCap, minGenCap)
Updated investInit_temp.gms
And some smaller updates

Implementing a new set "flowNode", which includes nodes with flows in them. Using it for increasing the performance of "periodicLoop" and "inputsLoop".

Implementing a new set "unitStarttype" to avoid generation of unused startup variables and constraints.

Implementing a new set "unitStarttype" to avoid generation of unused startup variables and constraints.

Rewrote '1e_inputs.gms' to improve readability (and hopefully performance). Unit startup costs are now calculated based on 'unitSizeGen' to scale the costs according to unit size.

Previously, the default startup cost and fuel consumption parameters applied to "hot" starts, which are impossible unless the hot start window is defined. Now the default startup parameters affect the "cold" startup, which is the startup always available to units with online variables.

Fixing an issue where time series form reserve requirements were not generated if no time series found in data (but were generated based on forecast data read in the loop). Now determines the need for reserves based on constant parameters or the "use_time_series" flag.

NOTE! This flag is redundant with "useTimeseries" and is pending removal...

Rewriting the efficiency approximation calculations, as well as reimplementing diagnostic COP and efficiency results.

Some minor readability and performance upgrades as well.

Added possibility to use input/changes.inc file in order to read changes for different setups when using Sceleton Titan

Added a constraint for maximum instantaneous share of generation/import from a group of units/transfer links

Moved reserve set definition from "periodicLoop" to "inputs". Minor changes to time series calculation, excluding unnecessary data in some cases.

Corrections to ramping constraints and testing different start-up types (hot, warm, cold) and minimum up/down times.

Added an online capacity variable. Start-up costs divided to unit and capacity based costs. Ramping variable changed from pu/min to MW/h. Added equations for constraining the number/capacity of online units and ramping of units.