Glossary

Reserve activated automatically by the transmission operator’s controller; after about 30 seconds it takes over from FCR and brings frequency back to 50 Hz. Batteries are the best source of aFRR.

Pooling several assets — plants, batteries, flexible load — into a portfolio that works the market as one. Deviations partly cancel out, and the combined volume counts for more.

The National Agency for Energy Regulation — approves market rules, including balancing and imbalances.

The grid operator’s document setting the technical conditions and approved capacity for connecting a plant.

Battery containers, converters (PCS), a transformer and a control system that charge and discharge on command. Described by power (MW) and energy (MWh).

A participant financially responsible for the difference between its declared schedule and the actual production or consumption of its portfolio.

A market participant that offers power reserves to the transmission operator and activates them on command, once its assets pass prequalification.

A forced reduction in a plant’s output, usually at noon, when the grid or the market cannot take all the energy.

The market where energy for the next day is bought and sold by the hour. In Moldova it has run since December 2025.

Software that decides when the battery charges, sells or stays in reserve, based on forecasts, prices and dispatcher commands.

Storing or buying energy in cheap hours and selling it in expensive ones. For a PV plant it usually means charging a battery at noon and delivering in the evening.

Charging the battery when power is cheap and selling it when it is expensive — usually from noon to the evening.

The European network of transmission system operators. Moldova has been synchronised with it since March 2022; Moldelectrica is an observer.

The first line of defence: responds automatically within seconds to a frequency deviation and stops it from falling or rising further.

A converter mode in which it sets voltage and frequency itself, like a synchronous machine, and helps a weak grid stay stable.

The difference between scheduled and actually delivered or consumed energy in a settlement period. It is settled at the imbalance price.

Lithium iron phosphate — a thermally stable, long-life battery chemistry, the standard for grid storage.

Reserve activated on the dispatcher’s command within minutes. It frees up aFRR and covers longer deviations.

Moldova’s transmission system operator: dispatches the power system and buys balancing services.

The entity that runs trading on the day-ahead market and calculates prices.

The bidirectional converter between battery and grid: charges and discharges the battery while controlling active and reactive power.

Tests through which the operator checks whether an asset can deliver a given balancing product with the required speed and accuracy.

A slower reserve that replaces reserves already activated so they are available again for the next event.

Supervisory control and data acquisition: collects data from equipment and sends commands.

One price for deviations in both directions in a period. It turns a forecast error into a direct cost for the producer.

How full the battery is, as a percentage of capacity. The EMS keeps it within limits that protect the battery and keep it ready for activations.