Wrong calculation of country-specific system costs

[cpschau]

With the current implementation of pypsa.Network.statistics the country-specific system costs cannot be retrieved as they currently are in the function get_economy. Links, that do not have a country assigned are not included in the calculation using the grouper get_country_and_carrier. Instead the grouper get_bus_and_carrier could be used, as it allows to filter for components of a specific country using the bus id. However, the CAPEX of transnational interconnector components such as AC lines, DC links or pipelines, would still have to be adjusted, as the costs should not be exclusively attributed to one country.

pypsa-de/scripts/pypsa-de/export_ariadne_variables.py

Line 4160 in c1e59d1

grouper = g.get_country_and_carrier

[cpschau]

One possible solution could look like this assuming an equal distribution of costs between the two countries that are connected by an interconnector component:

def get_component_mask(lines_or_links, country, countries):
    return ((lines_or_links.bus0.str.contains(country) & lines_or_links.bus1.str.contains("|".join(countries))) | (lines_or_links.bus0.str.contains("|".join(countries)) & lines_or_links.bus0.str.contains(country)))

def calc_ic_capex(n, country):
    countries = n.buses.country.unique()

    countries = countries[(countries != '')&(countries != country)] 
    ic_links_mask = get_component_mask(n.links, country, countries)
    ic_links = n.links.loc[ic_links_mask]

    ic_lines_mask = get_component_mask(n.lines, country, countries)
    ic_lines = n.lines.loc[ic_lines_mask]

    capex_ic_links = ic_links.p_nom_opt.mul(ic_links.capital_cost).sum()
    capex_ic_lines = ic_lines.s_nom_opt.mul(ic_lines.capital_cost).sum()
    
    return capex_ic_lines + capex_ic_links

def calc_system_costs_country(n, country):
    s = n.statistics(groupby=n.statistics.groupers.get_bus_and_carrier)
    s_country = s.filter(regex=country, axis=0)
    system_costs_country = s_country[["Capital Expenditure", "Operational Expenditure"]].sum().sum()
    ic_costs = calc_ic_capex(n, country)
    return system_costs_country + 0.5 * ic_costs

calc_system_costs_country(n, "DE")