BESS — Battery Energy Storage System

A grid-connected battery that can absorb electricity (charge) and feed it back (discharge). The flexibility asset studied throughout this dashboard.

EMS — Energy Management System

The controller that decides when the battery charges and discharges, optimising against market prices and grid tariffs. Each scenario runs one EMS strategy.

FCU — Flexibility Control Unit

The simulation component that models a storage unit together with its EMS. You will see this name in raw result files (result_FlexibilityControlUnit-*.csv); in the interface it appears as Storage & Flexibility.

DOE — Dynamic Operating Envelope

Time-varying import and export limits set by the grid operator for a connection point. The storage may optimise freely inside the envelope, giving the operator a network guarantee without fixed curtailment.

DAA / IDA

Day-Ahead Auction and Intraday Auction — the two wholesale market products traded here. Shown as 'Day-Ahead' and 'Intraday' in charts and tables.

State of charge (SoC)

How full the battery is, from 0 (empty) to 1 (full). Comparable to a fuel gauge.

Per unit (p.u.)

Voltage expressed relative to its nominal value: 1.00 p.u. is nominal, 0.95 is 5% below. Lets voltages be compared across voltage levels.

MV / LV

Medium voltage (typically 1–50 kV, the distribution backbone) and low voltage (below 1 kV, the level serving households).

N-1 security

The principle that a grid should keep operating within limits after the loss of any single component, such as one line or transformer.

PV

Photovoltaic generation. Distributed solar feed-in is one of the drivers of voltage rise and reverse power flow in the modelled grids.

TURPE7

The French regulated distribution grid tariff. Version 7 combines an energy charge with a peak capacity charge and time-of-use windows.

SimBench grid

A publicly available set of realistic benchmark distribution grids, used so results can be reproduced and compared by others.

Co-simulation

Running separate models — market, storage control, and grid power flow — as one coupled system, so each one's output becomes the next one's input at every timestep.

Battery storage system

A grid-connected battery that can absorb electricity (charge) and feed it back (discharge). Referred to as 'storage' throughout this dashboard.

Dispatch

The schedule of charging and discharging over time — how much power the storage takes from or feeds into the grid at each moment.

Control strategy

The optimisation logic that decides when to charge and discharge, based on market prices and grid tariffs. Each scenario uses one strategy.

Day-ahead market

Wholesale electricity auction where power is traded one day before delivery. Sets an hourly price used as an input to the control strategy.

Intraday market

Wholesale market trading closer to delivery time, allowing positions to be corrected after the day-ahead auction closes.

Price arbitrage

Charging when electricity is cheap and discharging when it is expensive, to earn the price difference.

Equivalent full cycle

One complete charge and discharge of the battery's full capacity. Used to express battery utilisation and wear independently of partial cycles.

Energy charge (volumetric)

Grid tariff component billed per unit of energy drawn (per kWh or MWh), regardless of when it is used. Known as 'AP' (Arbeitspreis) in the TURPE tariff.

Capacity charge (peak demand)

Grid tariff component billed on the highest power drawn during a period, rewarding a flatter load profile. Known as 'LP' (Leistungspreis) in the TURPE tariff.

Loading (%)

How much of a line's or transformer's rated capacity is in use. Above 100% the equipment is overloaded and may age faster or trip.

Simultaneity

The share of storage units charging or discharging in the same direction at the same time. High simultaneity concentrates stress on the grid.

Power flow calculation

The physics simulation that computes voltages and line loadings across the network for a given set of loads and generation.