Grid Connections:
Now and the Future
10th November 2010
Patrick Smart
Head of Commercial and Regulatory
www.senergyworld.com
Agenda
• Introduction to SEL
• Overview of Grid and Grid Process
• Technical challenges
• National Grid’s impact on renewables
• How to manage Grid risk
• The future of grid connections
Senergy Econnect Ltd
• Established as Econnect in 1995
• Grid connection of all renewable generation technologies
• Hagshaw Hill, North Hoyle – Landmark projects for UK
Renewables
• Electrical Engineering and Commercial and Regulatory
Consulting
• Now part of Senergy Group, based in Newcastle
The GB Network
Overview of Electricity Industry
1
Transmission
GB System
Operator
3 transmission owners
14 Distribution Network Operators
(7 companies)
NGETL
NGETL
Scottish Power, Scottish
Hydro-Electric
Distribution Network Areas
Securing Grid Capacity
• Accept a connection offer
– …which generally requires a down payment (£70K to £200k
for commercial onshore wind)
– …and a commitment to progress construction
• So when do I initiate the grid process? Planning or grid
first?
• Some information in the public domain – DNO Long Term
Development Statements.
DNO Connection Process
• DNOs obliged to offer terms to connect to network
• Submit competent application (likely DNO up front fee in
the near future)
• Offer within 3 months
• Open for acceptance for 30 days or 3 months. Can
normally be extended but not guaranteed.
• Acceptance usually requires initial down payment – to
cover detailed studies and design.
DNO Point of Connection Offers
• Non-contestable connection works only
• New Standards in effect from 1 October 2010
• Obliged to offer budget estimates within set period (20
WDs for commercial projects)
• PoC Offers - DNO liable for compensation of £150 per day
late!!!! (for applications received after 1 October 2010…..)
• All works offers – DNOs to include 4% margin on
contestable works
Connection Offer Process
• Offers of terms for connection open for acceptance for 30
days or 3 months.
• Can normally be extended but this is not guaranteed.
• Acceptance usually requires initial down payment - £70K
to £200k
• Obligation to agree construction programme
DNO Connection Offer Content
• Outline of connection solution
• Outline of DNO works, reinforcements and construction
program
• Technical and communication requirements
• User’s obligation (design to ENA standards)
• Price (often indicative until contracts placed)
• Connection cost and risk project specific
Connection Offer Process – National Grid
• Transmission System Impact
• Dash for Wind in late 2004 / 2005.
• Massive shortfall of grid capacity relative to applications /
agreements (note not necessarily consented wind)
• The “GB Queue”
• Much of the GB Queue connecting at distribution voltage
Connection Offer Process– National Grid
Connection Offer Process– National Grid
• Managed through embedded bilateral agreements
and the Statement of Works process
• “Large” generators must enter into a bilateral
agreement (BELLA or BEGA)
• Small / medium generators may be referred to
National Grid for a “Statement of Works”.
• National Grid responds with view on transmission
system impact
Key Technical Considerations
Three main network problems:
• Thermal capacity
• Fault levels
• Voltage rise
Further technical considerations:
• Harmonics
• Voltage Flicker
• Design requirements (e.g. G59)
If you cause technical problems, your connection will take
longer to complete and be more expensive.
Thermal Capacity
Overhead line
Safety clearance
Transformers
• Overheating leads to insulation failure
• Reverse power flow capability?
Switchgear
• Overheating leads to insulation failure
Cables
• Overheating leads to insulation failure
Fault Currents
Primary
Substation
Distribution
Feeder
Fault Current
Fault Current
G
Contribution of current to a fault on network can lead
to an overstressing of existing switchgear and is a major
limiting factor to the connection of embedded generation
Substation
Voltage Rise
Overhead line
Voltage
max
min
Substation
Voltage Rise - Mitigation
maximise
generation
Voltage
max
GenAVC
min
Within limits
Connection Offer Process – Key Messages
• Assess grid early (publicly available information)
• Engage with the DNO and stay in touch
• Ask about National Grid impact
• Plan submission of connection application in light of
process delays and obligation to commit c£100k
• Reflect outputs from assessment and DNO liaison in
application
Future Grid Connections
Transmission
Generators
Transmission Network
Transmission
Generators
Network Owners
Distribution Network
Distribution Generators
Consumers
Grid Connections in the Future
• Regulatory reform – RIIO (Revenue Incentives Innovation
Outputs)
• Key principles
– Focus on outputs and delivery (more from assets)
– Longer term view (decarbonisation)
– Reward for higher performance
– Encourage innovation (prizes)
• “£32 billion” of investment required
• What does that mean for grid connections…?
Grid Connections in the Future
• Who knows….watch the RIIO space..BUT
• Opportunities for new technologies / techniques to raise
long term efficiency
• Smart Grids (?) – from dynamic substation control to
domestic load switching.
• Electrical efficiency of connecting close to significant
points of demand.
• Extend on the principle of negative GDUoS for HV
connections.
Patrick Smart
Head of Commercial & Regulatory
0191 238 7344
patrick.smart@senergyworld.com