Constraint

1
Constraint

• Richard Ford
• UK Grid Connections Manager
• Renewable Energy Systems

2
Definitions

• Constraint
• Not enough network
• Location specific
• Winter evenings?
• Compensation
• Requires
• Network investment

• Curtailment
• Not enough demand
• System-wide
• Summer nights?
• No compensation
• Requires
• Interconnectors
• Storage

3
If there are constraints on the network

• When will they be lifted?
• How will they be applied?
• Should there be compensation?

4

• Given sufficient network investment, all
  generators can receive firm access and
  constraints can be zero.
• This may not be the optimum economic solution.
• Interaction between Network Owner and Network
  Operator costs

5

• Generators should be given the opportunity to
• offer prices for constrained running
• be paid when constraints are instructed
• Otherwise
• No signal for network reinforcement
• Distortion of energy market

6
Non firm access

• Delay connection of the generator until any
  network reinforcements are complete
• Connect generator without consideration of
  network reinforcements
• Connect generator on a partially firm basis with
  fully firm connection once network reinforcements
  are complete.
• Allow connection of generator on a non firm basis
  (i.e. no constraint payments) without a firm
  deadline for the connection to be made fully firm.

7
Non firm access

• Delay connection of the generator until any
  network reinforcements are complete
• GB approach
• Connect generator without consideration of
  network reinforcements
• Connect and manage
• Connect generator on a partially firm basis with
  fully firm connection once network reinforcements
  are complete.
• ROI approach
• Allow connection of generator on a non firm basis
  (i.e. no constraint payments) without a firm
  deadline for the connection to be made fully
  firm.
• NI approach