Taxes and capacity

Both are filled in from the built-in data of a region, so you only write them for a region energy-cost doesn’t know, or to change them.

Taxes

taxes is a list of versions, like a tariff. Unlike a tariff version, a tax version may have an end.

Field	What it is
start	When the rates start. Required.
end	When they stop. Optional.
default	The rate for everything no other rate covers, as a fraction: 6% is 0.06
rates	Other rates, each a rate and the columns of the bill it applies to

A column is three parts: the part of the bill (supplier, distributor, fees), the cost group and the cost type. * stands for any. The built-in Belgian electricity taxes:

taxes:
  - start: 2022-01-01T00:00:00+01:00
    default: 0.06
    rates:
      - rate: 0.0
        columns:
          - [fees, fixed, energy_fund]
          - ["*", injection, "*"]

That’s 6% on everything, except nothing on the energy fund and on anything paid or received for injection. When several columns match a cost, the most specific one wins, with the cost type counting most.

The bill shows taxes as a single total.

Capacity

Some distributors charge for the highest power a connection draws, its peak, instead of only for the energy. A capacity_rule says how that peak is measured:

Field	What it is
measurement_period	The period power is averaged over, such as PT15M
billing_period	The period whose highest value is the peak, such as P1M
window_periods	Optional: average the peak over this many billing periods, the current one included

The built-in Flemish rule is the Flemish capacity tariff: the average power per quarter-hour, the highest of each month, averaged over the last twelve months.

capacity_rule:
  measurement_period: PT15M
  billing_period: P1M
  window_periods: 12

Formulas marked capacity_based are charged on this peak. Meter data must be at least as fine as the measurement_period, so for Flanders every quarter-hour. For a full twelve-month average, pass a year of earlier data and set the bill’s start to the period you want billed.

If you already have the peaks, for example from a meter that measures them, you can give them to the meter directly and the rule’s averaging is skipped.