Level 2 · How the Electricity System Works · Module 04
Who Does What in Electricity?
Who are the actors, and who is responsible for what?
- 4
- connected lessons
- 8
- guided learning steps
- 155
- estimated minutes
The central idea
Who are the actors, and who is responsible for what?
Generation and electricity sales are competitive activities; transmission and distribution are regulated infrastructure monopolies.
Generation and electricity sales are competitive activities; transmission and distribution are regulated infrastructure monopolies. The public preview explains the operating logic, professional relevance and boundaries before the complete guided application.
Professional relevance
Why this matters beyond the classroom.
Project development: identify who applies, connects, forecasts, nominates and operates. Trading: assign positions, collateral, scheduling, balance responsibility and settlement. PPAs: separate seller, route-to-market provider, BRP, supplier and metering roles.
What you will learn
Four lessons that build one working mental model.
- 01
Physical System Actors
Generators, transmission system operators, distribution system operators, consumers and prosumers. The lesson follows physical electricity from injection to withdrawal and distinguishes asset ownership from system operation.
Electricity looks simple at the socket. Behind it sits a chain of assets, contracts, measurements, schedules, licences and institutions. A generator injects power. Network operators carry it through infrastructure. Traders and suppliers form commercial positions. A balance responsible party accounts for deviations. A balancing service provider may change output or demand when instructed. Market operators match orders. Regulators supervise monopoly and market behaviour. European bodies coordinate rules that cannot stop at national borders. The first professional discipline is therefore to ask “in which role?” A company may own a solar plant, employ an operations team, sell output to a trader, delegate balancing responsibility and provide reserve through an aggregator. Those are not five descriptions of the same responsibility. They are different layers connected by agreements, metering and data exchange. The core intuition of this module is structural. Generation and the sale of electricity are normally competitive activities: different parties can build assets, offer products and compete for customers. Transmission and distribution are infrastructure monopolies: duplicating complete electricity networks would usually be inefficient, so operators receive regulated responsibilities and must provide access under supervised rules. Competitive does not mean rule-free, and.
- 02
Commercial Market Actors
Suppliers, traders, aggregators, balance responsible parties, balancing service providers and power exchanges/NEMOs. The lesson separates title, contract, scheduling, settlement and physical delivery.
A supplier sells electricity to final customers. It procures energy, manages customer contracts, billing, service, regulatory disclosures and other retail obligations under national law. The supplier may buy power on exchanges, through bilateral contracts, from its own generation or through a portfolio manager. Its retail price can combine wholesale procurement, network charges, taxes, levies, risk premiums and service costs. A trader buys and sells wholesale electricity or related products to manage positions, arbitrage differences, provide liquidity or serve clients. A trader may never issue an end-user bill. Conversely, a supplier may have an internal trading desk. The corporate entity can hold both roles if permitted, but each transaction still has a wholesale or retail character. The distinction matters in PPAs and route-to-market structures. A producer may sell its metered output to a trader. The trader may hedge and resell volumes to a supplier. The supplier serves a factory. Physically, the electrons are pooled in the network; commercially, title and payment move through defined contracts. If the factory consumes during an hour when the original solar plant is not generating, the supplier must still meet its supply obligations through its portfolio..
- 03
Institutions and Regulated Responsibilities
National regulatory authorities, ACER, ENTSO-E, the EU DSO Entity and the European Commission. The lesson shows how legislation, regulation, coordination, network codes, methodologies and supervision fit together.
A power exchange provides an organised venue where standardised buy and sell orders can be submitted and matched. It can support transparent price formation, clearing and market data. A NEMO is an operator designated under EU rules to perform functions related to single day-ahead or intraday coupling. Market coupling combines orders and available cross-zonal capacity to calculate trades and prices across bidding zones. The process helps allocate scarce interconnector capacity implicitly through energy trading. The NEMO and the relevant coordinated arrangements perform market functions; TSOs provide and validate capacity and remain responsible for physical system operation. An accepted order creates commercial rights and obligations. It does not reserve a dedicated electron path from one named plant to one named buyer. Physical power follows the network. Participants settle the product and manage balance responsibility. The exchange does not repair a line, connect a customer or guarantee a generator’s output. Power exchange, clearing house and NEMO may be related in practice but should not be assumed identical for every purpose. Verify the legal operator, product rules, clearing arrangements, collateral, nomination process, delivery area and applicable designation. National regulatory authorities oversee electricity markets.
- 04
One MWh, Many Responsibilities
A complete role map for a renewable generator selling through a trader and supplier to consumers, while a TSO, DSO, BRP, BSP and NEMO perform different functions. The lesson focuses on handoffs, interfaces and failure modes.
A 100 MW solar SPV connects to a DSO network. An O&M contractor operates the plant. A trader buys pay-as-produced output and is also the project’s route-to-market provider. The trader delegates balance responsibility to a specialist BRP. A supplier buys part of the trader’s portfolio and serves industrial customers. A battery aggregator offers qualified flexibility as a BSP. Day-ahead orders are submitted through a NEMO. At noon, the plant produces 80 MWh while its latest market position is 85 MWh. The roles are: 1. The plant physically generates and injects 80 MWh, subject to connection and dispatch conditions. 2. The DSO operates the local network, meter interfaces and connection under national arrangements. 3. The route-to-market provider submitted the commercial orders and manages contractual delivery. 4. The NEMO matched orders; it did not route dedicated electrons. 5. The BRP’s portfolio contains the relevant position and measured allocation. The 5 MWh difference contributes to imbalance unless offset elsewhere. 6. The supplier meets its customers’ retail obligations from its portfolio, not from a guaranteed physical path to this plant. 7. If the TSO activates the battery’s balancing bid, the BSP must deliver the.
Key takeaways
What should remain after the details.
- Ask "in which role?" before assigning responsibility.
- Separate physical, operational, commercial and regulatory layers.
- Generators produce; network operators transport and operate infrastructure.
- Suppliers serve final customers; traders manage wholesale positions.
- Consumers can also generate, store and provide flexibility.
- Aggregators coordinate portfolios without physically merging connections.
- BRPs bear financial responsibility for imbalance.
- BSPs provide qualified balancing services.
Correct the shortcut
Common misconceptions
- The TSO buys all generated electricity. It operates the system and procures defined services; ordinary energy sales follow market arrangements.
- This shortcut is incomplete; apply the module’s definitions, system boundary and operating constraints before drawing a conclusion.
- The DSO is always the supplier. Network operation and energy supply are distinct roles.
- This shortcut is incomplete; apply the module’s definitions, system boundary and operating constraints before drawing a conclusion.
- A trader serves end-consumers. Wholesale trading does not itself establish a retail supply relationship.
- This shortcut is incomplete; apply the module’s definitions, system boundary and operating constraints before drawing a conclusion.
- A prosumer leaves the system. Most remain connected, metered and commercially settled.
- This shortcut is incomplete; apply the module’s definitions, system boundary and operating constraints before drawing a conclusion.
- An aggregator creates one physical power plant. It coordinates distributed assets that remain at separate nodes.
- This shortcut is incomplete; apply the module’s definitions, system boundary and operating constraints before drawing a conclusion.
Worked reasoning
Worked case: one solar MWh
A 100 MW solar SPV connects to a DSO network. An O&M contractor operates the plant. A trader buys pay-as-produced output and is also the project’s route-to-market provider. The trader delegates balance responsibility to a specialist BRP. A supplier buys part of the trader’s portfolio and serves industrial customers. A battery aggregator offers qualified flexibility as a BSP. Day-ahead orders are submitted through a NEMO. At noon, the plant produces 80 MWh while its latest market position is 85 MWh. The roles are: 1. The plant physically generates and injects 80 MWh, subject to connection and dispatch conditions. 2. The DSO operates the local network, meter interfaces and connection under national arrangements. 3. The route-to-market provider submitted the commercial orders and manages contractual delivery. 4. The NEMO matched orders; it did not route dedicated electrons. 5. The BRP’s portfolio contains the relevant position and measured allocation. The 5 MWh difference contributes to imbalance unless offset elsewhere. 6. The supplier meets its customers’ retail obligations from its portfolio, not from a guaranteed physical path to this plant. 7. If the TSO activates the battery’s balancing bid, the BSP must deliver the.
Concept map
The vocabulary this module connects.
- Generators
- transmission system operators
- distribution system operators
- consumers and prosumers. The lesson follows physical electricity from injection to withdrawal and distinguishes asset ownership from system operation.
- Suppliers
- traders
- aggregators
- balance responsible parties
- balancing service providers and power exchanges/NEMOs. The lesson separates title
- contract
- scheduling
- settlement and physical delivery.
- National regulatory authorities
- ACER
- ENTSO-E
- the EU DSO Entity and the European Commission. The lesson shows how legislation
- regulation
- coordination
- network codes
- methodologies and supervision fit together.
- A complete role map for a renewable generator selling through a trader and supplier to consumers
- while a TSO
- DSO
- BRP
- BSP and NEMO perform different functions. The lesson focuses on handoffs
- interfaces and failure modes.
Evidence boundary
Selected authoritative sources
Research reviewed 2026-08-13. The complete learning package contains the full reference trail and explains where simplified beginner models stop.
- Directive (EU) 2019/944, consolidated text - definitions, consumer, supplier, aggregator, TSO/DSO, unbundling and regulatory authoritiesResearch source used in the Who Does What in Electricity? learning package
- Regulation (EU) 2019/943, consolidated text - market participant, NEMO, balancing, BRP, BSP and market principlesResearch source used in the Who Does What in Electricity? learning package
- Regulation (EU) 2019/942, consolidated text - ACER establishment, objectives and tasksResearch source used in the Who Does What in Electricity? learning package
- Commission Regulation (EU) 2015/1222 - capacity allocation, congestion management and NEMO functionsResearch source used in the Who Does What in Electricity? learning package
- European Commission, Electricity market designResearch source used in the Who Does What in Electricity? learning package
Questions answered
Who Does What in Electricity? FAQ
Who are the actors, and who is responsible for what?
Generation and electricity sales are competitive activities; transmission and distribution are regulated infrastructure monopolies.
Why does who does what in electricity? matter to energy professionals?
Project development: identify who applies, connects, forecasts, nominates and operates. Trading: assign positions, collateral, scheduling, balance responsibility and settlement. PPAs: separate seller, route-to-market provider, BRP, supplier and metering roles.
What will I learn in this Who Does What in Electricity? module?
You will connect Generators, transmission system operators, distribution system operators, consumers and prosumers. The lesson follows physical electricity from injection to withdrawal and distinguishes asset ownership from system operation.; Suppliers, traders, aggregators, balance responsible parties, balancing service providers and power exchanges/NEMOs. The lesson separates title, contract, scheduling, settlement and physical delivery.; National regulatory authorities, ACER, ENTSO-E, the EU DSO Entity and the European Commission. The lesson shows how legislation, regulation, coordination, network codes, methodologies and supervision fit together.; A complete role map for a renewable generator selling through a trader and supplier to consumers, while a TSO, DSO, BRP, BSP and NEMO perform different functions. The lesson focuses on handoffs, interfaces and failure modes..
What remains inside the complete learning module?
The complete module contains the full readings, guided decisions, feedback, mastery assessment and professional challenge, with progress recorded in the learner experience.
Learn, apply, test
Reading is only the beginning.
The complete module adds guided decisions, feedback, a mastery assessment and a professional challenge. Your progress remains in your learner dashboard.