What is a zone

Defining zones

Electricity Maps traces back the origin of the consumed electricity for more than 200 zones across the world. We are defining a zone as the physical grid on which consumers and producers are connected and which is controlled by a grid operator. Some grid operators are defining sub divisions for their grids like bidding zones. When those are available with the right data on this level, we aim at displaying the smallest subdivision available.

A zone might not always map to a political entity (country, state or region). The most prominent example of this is the US where the BA zones do not match with state lines.

At Electricity Maps, a zone is defined as a grid where electricity is consumed, and balanced by a grid operator.

Grid operators

The grid operator is the entity responsible for balancing electricity production and consumption on its grid, as well as imports or exports of electricity from/to neighboring grids. They take different names in different regions of the world with different responsibilities:

• Balancing authorities (BA) in Northern America Balancing authorities, a functional role defined by the North American Electric Reliability Corporation (NERC), are mainly responsible for balancing electricity supply, demand, and interchange on their electric systems in real time.
• Transmission System Operator (TSO) in Europe and Japan European Transmission System Operators (TSOs) are entities operating independently from the other electricity market players and are responsible for the bulk transmission of electric power on the main high voltage electric networks. TSOs provide grid access to the electricity market players (i.e. generating companies, traders, suppliers, distributors and directly connected customers) according to non-discriminatory and transparent rules.
• Regional and National Load Despatch Centres in India are responsible for balancing the grid between consumers and producers in their respective regions as well as handling exchanges with other grids.
• Energy Market Operator in Australia
• …

Retired grid operators/zones

It can happen that grid operators are discontinued. In most cases, a new grid operator will take over operations. The new grid operator can be an entirely new player or an existing operator will take over the zone, effectively merging two zones. In the latter case, we will merge the zones on our app and reprocess our historical dataset to reallocate the data from the retiring zone to the newly extended zone. Therefore, ensuring that our dataset remains consistent in terms of zones throughout time. Retired zones are archived in the retired zones folder. So far, we did this for the following zones:

• US-FLA-NSB has been integrated within US-FLA-FPL.
• US-SE-AEC has been integrated within US-SE-SOCO.

Generation Only Zones

Some grid operators are only producing electricity which is then entirely supplied to another grid due to purchase agreements. In their zone, there are no consumers of electricity.

To simplify zone definitions, we merged those zones together with neighbouring zones in which the electricity is actually consumed. We do this when we are able to know where the electricity goes.

United States of America:

Generation only balancing authorities are listed by the EIA in the section Generation-only BAs

We are currently doing the following transfers:

• US-SW-SRP (Salt River Project) is integrating all the produced electricity from US-SW-DEAA (Arlington Valley, LLC – AVBA) and US-SW-HGMA (New Harquahala Generating Company, LLC – HGBA).
• US-NW-NWMT (Northwestern Energy (Nwmt)) is integrating all the produced electricity from US-NW-GWA (NaturEner Power Watch, LLC) and US-NW-WWA (NaturEner Wind Watch, LLC).
• US-SW-WALC (Western Area Power Administration - Desert Southwest Region) is integrating all the produced electricity from US-SW-GRIF (Griffith Energy, LLC).
• US-NW-PACW (PacifiCorp West) is integrating all gas related electricity production from US-NW-AVRN (Avangrid Renewables, LLC).
• US-NW-BPAT (Bonneville Power Administration) is integrating all wind related electricity production from US-NW-AVRN (Avangrid Renewables, LLC).
• US-CAR-SC (South Carolina Public Service Authority) is integrating a third of the nuclear related electricity production from US-CAR-SCEG (Dominion Energy South Carolina, Inc.).