In the model the operation and maintenance costs (O&M) are split into fixed and variable components. Fixed O&M costs are costs that incur irrespective of use and therefore can be viewed as long-run maintenance costs, whereas variable O&M costs are linked to the maintenance of the capacity that has been used during a year. Start-up costs are modelled separately.
Operation and maintenance costs
The OECD-publication “Projected Costs of Generating Electricity 2010 (OECD 2010) provides estimates for total O&M costs, so other sources have been used for the split between fixed and variable costs. Tidball et al. (2010), NREL (2012) and UK Costs of Generating Electricity 2010 provide more detailed information about O&M costs. Schröder et al. (2013) provides a compilation of different studies and their assumptions for fixed and variable O&M costs for different technologies. The dataset for LIBEMOD is based on an assessment of these sources.
Costs from the publication Projected costs of generating electricity (OECD 2010) have been used for natural gas, steam coal, lignite and nuclear power plants. For bio power IRENA (2012) has been used, and for waste power plants DEA (2010). The O&M costs for solar power, geothermal and other renewables are based on data from the technology briefs from IEA ETSAP. The costs for wind power are based on OECD (2010) and IRENA (2012).
For some of the immature technologies the O&M costs for existing plants differ from those for new power plants.
An accurate modelling of start-up costs requires a model with a power plant specific resolution. In LIBEMOD there are only four periods throughout a year, namely day/night and summer/winter. As a result the modelling of start-up costs is very simplified and the whole fleet of power plants is in reality considered as one block.
Each technology has a given amount of cold starts per season and the start-up costs consists of two components. One is linked to fuel costs due to the higher fuel use during the starting process, and the other to fatigue costs as a result of wear and tear on the power plant from stopping and starting. Data from DENA (2005) has been used for natural gas (combined cycle gas turbine), hard coal, lignite and nuclear power plants. For waste power and biopower own assumptions have been made.