It includes cost assumptions for all included technologies for specific
years from various sources, namely for
- discount rate,
- lifetime,
- investment (CAPEX),
- fixed operation and maintenance (FOM),
- variable operation and maintenance (VOM),
- fuel costs,
- efficiency, and
- carbon-dioxide intensity.
The given overnight capital costs are annualised to net present costs
with a discount rate of :math:`r` over the economic lifetime :math:`n` using the annuity factor
..math::
a = \frac{1-(1+r)^{-n}}{r}.
Based on the parameters above the ``marginal_cost`` and ``capital_cost`` of the system components are calculated.
Modifying Cost Assumptions
==========================
Some cost assumptions (e.g. marginal cost and capital cost) can be directly overwritten in the ``config.yaml`` (cf. Section :ref:`costs_cf` in :ref:`config`).
To change cost assumptions in more detail, modify cost assumptions directly in ``resources/costs.csv`` as this is not yet supported through the config file.
You can also build multiple different cost databases. Make a renamed copy of ``resources/costs.csv`` (e.g. ``data/costs-optimistic.csv``) and set the variable ``COSTS=data/costs-optimistic.csv`` in the ``Snakefile``.
