Heat maps

Heat maps

When connecting distributed generation to our network the main limiting factors that may affect your connection are fault level and thermal ratings.

Before you apply we would recommend taking a look at our fault level and thermal capacity heat maps to see if the site you're looking to connect may be affected. Where thermal and/or fault levels are high, your connection may need reinforcement.

Fault level maps

Connecting DG to our network increases the amount of energy supplied into a potential fault on the network. The network has a limited ability to accept fault energy that is dictated by the fault rating of the network’s equipment and plant. The standing fault level and equipment rating therefore are a potential constraint on the ability to connect DG. The following maps show the distribution areas of 132/33kV substations.

The area colour indicates the impact of connection to the busbars at that substation.

The 33kV fault map indicates the potential impact of a new 25MW generation connection, and the HV fault map indicates the potential impact of a  new 10MW generation connection.

Key

33kV Fault map:

  • Green  - the fault level is less than 95% of the fault rating of the substation and likely to be able to connect a 25MW generator
  • Amber - the fault rating is between 95% and 100% of the fault rating of the substation and connection of 25MW will need consideration.
  • Red - the fault level is in excess of 100% of the fault rating of the substation and unlikely to be able to connect a 25MW generator without reinforcement

HV Fault map:

  • Green  - the fault level is less than 95% of the fault rating of the substation and likely to be able to connect a 10MW generator
  • Amber - the fault rating is between 95% and 100% of the fault rating of the substation and connection of 10MW will need consideration.
  • Red - the fault level is in excess of 100% of the fault rating of the substation and unlikely to be able to connect a 10MW generator without reinforcement

Thermal capacity maps

To be able to connect your generation to the network there needs to be available capacity to accept the electricity.  The Thermal Capacity map illustrates the amount of spare capacity available when connecting generation at the busbars of a 132/33kV substation.  The Red/Amber/Green on the Thermal Capacity map show the likelihood that a new generator would create the need for reinforcement on the Electricity North West distribution network.

Key

  • Green - Available spare capacity to connect DG
  • Amber - Limited spare capacity constraining the ability to connect DG
  • Red - Unlikely to have sufficient capacity to connect DG without reinforcement