IEEE Power & Energy Magazine - September/October 2019 - 61

Roles in the European Electricity System
In the energy market, there is a division between the physical

portfolio of contracted producers and consumers. Through

infrastructure and the energy supply chain. The administra-

contractual relations, each producer/consumer is part of

tive processes used to coordinate these two factors are or-

the portfolio of exactly one BRP. By balancing its own con-

ganized in well-documented and structured data exchange

tract portfolio, the BRP contributes to balancing the overall

protocols with clearly defined roles and responsibilities. The

grid. The TSO-level market mechanisms for (near)-real-

European Network of Transmission System Operators for

time balancing and reserves give the BRPs economic incen-

Electricity (ENTSO-E), representing 43 electricity transmis-

tives to balance their portfolio close to real time. Because

sion system operators (TSOs) from 36 countries across Eu-

the BRPs play a key role in maintaining system-wide bal-

rope, has developed the Harmonized Electricity Role Model,

ancing, there is a strict authorization program performed

which defines a common terminology for the European in-

by the TSOs to assign and recognize BRPs. Traditionally,

ternal energy market and related information technology

BRPs balance their demand and supply either by directly

development. Here we present the most important and rele-

dispatching power plants (if there is a contractual agree-

vant roles and how these roles change with the introduction

ment) or via trading on the various energy markets. Smart

of demand-side flexibility trade.

grid technology provides the additional optimization op-

The producer is the party producing electricity. Traditionally, these are centralized power plants. The decentralization

tion of activating the flexibility offered by prosumers, possibly through an aggregator.

of electricity production adds many additional parties play-

The aggregator is an up-and-coming role in the Euro-

ing this role. In essence, the role remains unchanged, but

pean market system. As such, it is not explicitly mentioned

the operating conditions may change drastically due to the

in the ENTSO-E role model. The aggregator role consists of

high penetration of variable distributed energy resources and

accumulating customers'/prosumers' flexibility and steer-

changes in the merit order of total production on every level

ing this aggregate to create value. Value creation can be

of the system.

done on behalf of a single BRP (by contributing to the BRP's

The consumer is the party consuming electricity. This

portfolio balance) or through transactions on a market for

ranges from a small one-person household to large in-

electricity. When this is a local market at the level of the

dustrial companies. Due to decentralization, increasing

distribution grid, the aggregator may deliver distribution

numbers of consumers are assuming the additional role of

system services (such as congestion management or voltage

producer. A party filling both roles is referred to as a pro-

management) to the distribution system operator (DSO).

sumer, although this is not an official term in the ENTSO-E

The aggregator provides an opportunity for prosumers to

role model.

access the market. Prosumers who transact via an aggrega-

The TSO is responsible for the transport of energy in a
given area from centralized energy producers to the dis-

tor in the (local) market are able to economically optimize
the use of their assets.

tribution grid operators over its high-voltage grid. One of

The traditional distribution network operator's role is

the core responsibilities of a TSO is maintaining system

currently evolving into a DSO's role. The DSO facilitates the

balance and taking corrective actions to restore it. This

physical distribution of energy in a given area over the low-

includes responsibility for system security and frequency

to-medium voltage distribution grid to its connected con-

control, congestion management, and voltage support in

sumers and producers (residential and small-/medium-sized

transmission networks. To do so, in most European coun-

enterprises). The role of the DSO, in this case, is similar to

tries there is a balancing market, which is an institutional

the role of the TSO, except for the voltages and connection

arrangement that establishes market-based instruments

capacities involved.

for balance management. In general, most TSOs are re-

Finally, an energy service company offers additional en-

sponsible for implementing a proper procurement pro-

ergy-related services to end users but is not directly active in

cess of balancing services from the balance responsible

the energy value chain or physical infrastructure itself. Tradi-

parties (BRPs). The procurement process typically in-

tionally, the supplier sells the electricity to consumers. The

cludes coordination processes such as energy scheduling

supplier agrees to commercial conditions with its customers

and imbalance settlements.

for the procurement of energy. In some cases, supplier com-

A BRP is a commercial role in the energy supply chain
responsible for actively balancing supply and demand for a

september/october 2019

panies also assume the aggregator role, while independent
aggregator companies are emerging at the same time.

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IEEE Power & Energy Magazine - September/October 2019

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