Profitability should be related to OPEX and CAPEX, not to variable and fixed costs

[AlexanderWirtz]

As discussed with @JAlsem.

The current definition of profitability is not correct:

1. :profitable (if income >= total costs)
2. :conditionally_profitable (if variable costs =< income < total costs)
3. :unprofitable (if income < variable costs)

Since a plant the runs always earns back its variable costs (since electricity price is always higher than variable costs IFF a plant is running, otherwise it wouldn't be running), the comparison between variable and fixed costs is rather trivial.

The crux is that we want to know if the plant makes enough money to stay open. In effect this means we want to know if it covers its OPEX = variable costs + fixed O&M cost

Change the profitability definition as follows therefore:

1. :profitable (if income >= total costs)
2. :conditionally_profitable (if OPEX =< income < total costs)
3. :unprofitable (if income < OPEX)

Note that since:

total costs = OPEX + CAPEX = variable costs + fixed costs

it is not necessary to define CAPEX anywhere.

We need to calculate OPEX in merit module, since variable costs are not input but output.

We need to make fixed_operation_and_maintenance_costs_per_year an input for each (dispatchable) participant in order to be able to calculate OPEX.

[wmeyers]

I would still define CAPEX, just to make sure that you don't have to calculate it every time you want to know it

[dennisquintel]

Actions:

• Add definition of operational_expenses in the README please
• Some more background information, such as: what is exactly defined as variable costs.
• Add this attribute to Producer

[AlexanderWirtz]

Also see issues #6 and #7

[JAlsem]

This is resolved in issue #27 Definition of operational_expenses is added to README and variable costs are defined as output.