Control areas and balancing groups
Germany’s transmission grid is divided into four TSO control areas
(Regelzonen):
n:lead operates one balancing group (Bilanzkreis) per control area for
the customer. A balancing group is a virtual energy account with its TSO:
all physical in-feeds/out-takes and all commercial schedules of the
portfolio in that area are booked into it.
A balancing group must net to zero for every quarter-hour. Residual
imbalances are settled at the imbalance price (Ausgleichsenergie) — the
entire purpose of this service is to nominate schedules that avoid that.
What a schedule contains
A balancing-group schedule consists of:
- the production forecast of the portfolio in that area (in-feed),
- the consumption forecast (off-take),
- all trades with counterparties: the EPEX/ECC exchange delivery (home
group only) and the cross-control-area transfers between our own groups.
Trades are aggregated per direction and counterparty: for each
counterparty there is at most one incoming and one outgoing series, values
are non-negative, and a negative flow simply appears in the opposite
direction. A correct schedule sums to zero at every interval:
The physical side (load, generation) is allocated into the balancing group
by the DSOs/TSO based on metering — the BRP does not nominate it; the
forecasts in the schedule are the BRP’s declared expectation of it. n:lead
computes these quantities from your data and submits the resulting
schedules to the TSOs.
Quarter-hours and daylight saving
Everything is quarter-hourly in Europe/Berlin, local midnight to
midnight:
The service computes the expected count from the timezone database and
rejects forecasts with any other length — a 96-value forecast for a DST day
is a validation error, not something to silently pad.
One bidding zone, one home area
Germany is a single day-ahead bidding zone: the EPEX day-ahead trade is
one volume for the whole German position. Physical delivery (via ECC, the
exchange’s clearing house) lands in one balancing group — the home
balancing group, in a home control area agreed as part of your setup.
That creates the central distribution problem this service solves: the other
three balancing groups never see the exchange delivery directly, so the home
group must pass their share on via matched cross-control-area transfer
pairs (out of home / into target). How the quantities are derived is on the
Core Algorithm page.
Sign conventions