efaciency

A package to simplify working with EFA blocks and settlement periods in the GB electricity trading system.

Installation

This package can be installed via pip:

$ pip install efaciency

Examples

Settlement periods

Get the starting timestamp for a settlement period.

>>> from datetime import date, datetime
>>> import efaciency

>>> efaciency.sp.to_ts(settlement_period=4)  # defaults to today as settlement date
datetime.datetime(2025, 2, 18, 1, 30, tzinfo=zoneinfo.ZoneInfo(key='Europe/London'))

>>> efaciency.sp.to_ts(settlement_period=13, settlement_date=date(2025, 5, 23))
datetime.datetime(2025, 5, 23, 6, 0, tzinfo=zoneinfo.ZoneInfo(key='Europe/London'))

You can also get the settlement for a given timestamp:

>>> efaciency.sp.from_ts(ts=datetime(2025, 1, 12, 17, 30))
36

EFA blocks

Get the starting and ending timestamp for an EFA block.

>>> from datetime import date, datetime
>>> import efaciency

>>> efaciency.block.to_start_ts(efa_block=3)  # defaults to today as EFA date
datetime.datetime(2025, 2, 18, 7, 0, tzinfo=zoneinfo.ZoneInfo(key='Europe/London'))

>>> efaciency.block.to_start_ts(efa_block=1, efa_date=date(2025, 5, 23))
datetime.datetime(2025, 5, 22, 23, 0, tzinfo=zoneinfo.ZoneInfo(key='Europe/London'))

You can also get the EFA block for a given timestamp:

>>> efaciency.block.from_ts(ts=datetime(2025, 1, 12, 17, 30))
5

What about clock change?

If a datetime with no timezone is provided, efaciency always assumes Europe/London timezone.

On clock change days, a tz-aware datetime must be passed or the fold parameter must be used.

>>> efaciency.sp.from_ts(datetime(2025, 10, 26, 1))
3

>>> efaciency.sp.from_ts(datetime(2025, 10, 26, 1).replace(fold=1))
5

Usage with Pandas or Polars

Examples of efaciency usage with Pandas or Polars dataframes:

# pandas
df["sp"] = df["ts"].apply(efaciency.sp.from_ts)
# polars
df.with_columns(pl.col("ts").map_elements(efaciency.sp.from_ts, return_dtype=pl.Int64).alias("sp"))

CLI

You can also use the efaciency CLI:

efaciency --help

Contribution

Please make a pull request or log an issue on GitHub.

License

Code is released as free software under the MIT License (see LICENSE file).