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www.senergyworld.com
Grid Connections:
Now and the Future
Patrick SmartHead of Commercial and Regulatory
10th November 2010
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
Overview of Electricity Industry
1TransmissionGB System
Operator
3 transmission owners
14 Distribution Network Operators (7 companies)
NGETL
NGETLScottish Power, Scottish
Hydro-Electric
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
• 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.
Transformers
Overhead line
• Overheating leads to insulation failure• Reverse power flow capability?
Switchgear
• Overheating leads to insulation failure
Cables• Overheating leads to insulation failure
Safety clearance
Thermal Capacity
Fault CurrentFault CurrentGGFault CurrentFault Current
Contribution of current to a fault on network can lead to an overstressing of existing switchgear and is a majorlimiting factor to the connection of embedded generation
Primary Substation
Distribution Feeder
Fault Currents
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
Distribution Network
Distribution GeneratorsConsumers
Network Owners
Transmission Generators
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.