1. Technical challenges in the power system Lewis Dale, 18 th Nov 2009,

2. 2 Content  National Grid  Grid development & operations - the immediate tasks  GB  Europe  Technical challenges

3. Transmission – our activities Transmission UK – electricity and gas Transmission US – electricity Electricity transmission owner Gas transmission owner Electricity system operator Gas system operator French interconnector LNG storage Electricity transmission owner/operator Canadian interconnector We own the electricity transmission system in England and Wales. Our assets comprise ~7,200km of overhead line; ~675km of underground cable; and 337 substations at 244 sites. We are the Great Britain System Operator, responsible for managing the operations of both the England and Wales transmission system that we own, and also the two independently owned high-voltage electricity transmission networks in Scotland. We are the gas national transmission system operator, responsible for managing the operations of the Great Britain transmission system that we own. We own the gas national transmission system in Great Britain. Our assets comprise ~7,400km of high pressure gas pipe and 26 compressor stations, connecting to 8 regional distribution networks and to third party independent systems. We own and operate the UK assets, and a portion of the sub sea cables, that comprise the electricity interconnector between England and France as part of a joint agreement with the French transmission operator. We own and operate four liquefied natural gas (LNG) storage facilities in Great Britain. We own and operate the electricity transmission network spanning upstate New York, Massachusetts, Rhode Island, New Hampshire, and Vermont. Our assets comprise ~13,700km of overhead line; ~160km of underground cable; and 501 substations. We own and operate a 224km direct current transmission line rated at 450kV that is a key section of an electricity interconnector between new England and Canada.

4. Gas Distribution – our activities Gas Distribution US Gas Distribution UK UK Networks Gas Distribution US US Networks UK Customers US Customers UK additional services US additional services Comprises four of the eight regional gas distribution networks in Great Britain Comprises gas distribution networks across the northeastern US, located in service territories in upstate New York, New York City, Long Island, Massachusetts, New Hampshire and Rhode Island. Our network of approximately 58,000 kilometres of gas pipelines covers an area of approximately 28,800 square kilometres. Comprise approximately 132,000 kilometres of gas distribution pipelines. We transport gas on behalf of approximately 33 active shippers from the gas national transmission system to 10.8 million consumers. Provide services to 3.5 million consumers. In addition we also manage the national emergency number for all the gas distribution networks and for other transporters in the UK. Our core services are the operation and emergency responses for each of our gas distribution networks, in addition to billing, customer service and supply services. Gas Distribution UK

5. Electricity Distribution & Generation – our activities Electricity Distribution & Generation operations Electricity distribution Long Island generation We own and manage electricity distribution networks in New York, Massachusetts, Rhode Island and New Hampshire. Our assets comprise ~116,000km of electricity circuits, serving ~3.4m electricity customers. We own 57 electricity generation plants on Long Island that together provide 4.1GW of power under regulated contract to the Long Island Power Authority (LIPA). We manage fuel supplies for LIPA to fuel our plants and purchase energy, capacity and ancillary services in the open market on LIPA’s behalf. LIPA T&D services On Long Island, we are responsible for managing the electricity transmission and distribution system on behalf of LIPA. LIPA owns approximately 2,100km of transmission lines, ~170 substations, and ~21,000km of distribution circuits, serving ~1.1m electricity customers.

6. National Grid’s environmental commitments  Reduce our own CO2 emissions by 80% by 2050  Continue our 30 year programme to replace iron gas mains - reducing methane leakage  Installing generation to recover energy at gas network pressure reduction stations  Improve efficiency of gas compressors  Reduce SF6 leakage from our electricity equipment

7. Grid developments GB Europe

8.  Plant closures…  12GW coal & oil (LCPD)  7.5GW nuclear  Demand growth ~0.5% pa  Incremental nuclear  Lifetime extensions  Two new stations in 2020  Modest renewable growth  6GW offshore & 7GW onshore  Strong fossil growth  3GW of new supercritical coal (some with CCS)  15GW new gas  Gas dominates at 44% share 2020 Target DescriptionProgress EU Renewable Energy Target; 15% of final energy demand 2050 CO 2 Target on correct ‘flight path’ Scottish Renewables Target Summary Generation gap caused by closures is largely filled with gas-fired plant, augmented with incremental nuclear and some renewable wind Risk of missing renewables targets Business as Usual scenario

9.  Plant closures  12GW Coal & oil LCPD  7.5GW nuclear  Some gas & additional coal  Significant new renewable  30 GW wind (19GW offshore, 11GW onshore)  Some tidal, wave, biomass & solar PV  Significant new non renewable build  3GW of new nuclear  3GW of new supercritical coal (some CCS)  11GW of new gas  Renewable share grows from 5% to 36%  Electricity demand remains flat  Reductions from energy efficiency  Increases from heat pumps & cars  Heat & transport efficiencies also required 2020 Target DescriptionProgress UK Renewable Energy Target 15% of final energy demand 2050 CO 2 Target on correct ‘flight path’ Scottish Renewables Target Summary Generation gap caused by closures is filled with wind, augmented by gas & clean coal. Nuclear returns in 2020. What might be needed? Gone Green Scenario

10. GB network developments  Plant closures  12GW Coal & oil LCPD  7.5GW nuclear  Some gas & additional coal  Significant new renewables  30 GW wind (19GW offshore & 11GW onshore)  Some tidal, wave, biomass & solar PV  Significant new non renewable build  3GW of new nuclear  3GW of new supercritical coal  11GW of new gas  Major new interconnection  Renewable share of generation grows from 5% to 36%  Electricity demand remains flat  Energy efficiency  Heat pumps & Cars France 2 Belgium BritNed Ireland France 1 NIreland Norway

11. Reinforcement cost - summary Onshore Offshore 7500 (From Ofgem estimate of £15bn for 38GW)

12. Wind variability: short-term reserves Wind output at peak electricity demand for 2008/09 Reserve requirements depend on forecast accuracy and diversity

13. A European Approach Exploit wind diversity Share reserves & storage Maximise CO2 benefits Co-ordination needed given cross-border impacts already experienced

14. DRAFT - Existing submarine cables (2015) - New submarine cable foreseen until 2015 - National grid development plan for 2015 - Candidates for grid reinforcement measures beyond 2015 (long-term RMM) - Offshore wind park cluster until 2015 2015 Grid Development in Europe IE NL DE 2008: 70GW wind. 2015: 140-180GW

15. Operational measures Phase shifting transformers (quad boosters) –Control power sharing on parallel circuits maximising useable capacity –Require co-ordination across network Special protection (intertrip) schemes –Alleviate post-fault conditions by using wider reserves –Co-ordination needed to ensure reserves adequate Dynamic line ratings –Monitor conductor temperatures and sags permitting higher pre and post fault ratings –Voltage and stability issues become more pressing

16. Wind power outage in Spain in 2008 due to voltage dipStability Power system oscillation modes N-S & E-W

17. System control Decentralised markets discover/encourage efficient conventional generation behaviour But central system operators have best information to forecast wind and demand and are best able to act strategically

18. Offshore grids  Significant synergies achievable in offshore grids  Requires multi-terminal HVDC (offshore) Large amounts of wind power coming onshore Interconnector flow cheaper to dearer Wind output sold to cheaper market

19. Implications of SMART technology  Transmission already actively managed (and development will continue)  Real-time re-despatching  Dynamic line ratings (real-time monitoring of temperatures/sags & stability limits)  Network flow control (phase shift transformers, HVDC link & switching)  Special protection schemes (post-fault actions)  Increasingly, wide area monitoring and control  Can SMART technology bring new demand side measures?

20. Smart Meter Technology Penetration Smart Home Smart Grid ConsumerSupplierDNO / DSOSOTO  Price awareness / sensitivity*  Reduced use *  Peak avoidance  Saved costs from AMR*  Tariff targeting  Improved planning data / investment planning*  Modest reduction in peak demands*  Better planning data from DNOs*  Bulk response to tariffs and TOU pricing. reduced use / peak avoidance*  Intelligent appliances*  More sophisticated tariffs / ‘real’ time price signals (Capacity / energy driven)  Fault detection  Quality of supply (e.g. voltage, pressure, CV)*  TOU capacity pricing signals  Some demand alignment with intermittent generation / scarcity of fuel*  Greater peak avoidance  Higher demands over minimums  Greater peak avoidance*  Appliances / demand response to external range of drivers  Supplier balancing pre and in BM  Direct intermittent generation contracts.  Gen capacity avoidance  Real time Network Capacity Management  Micro generation / storage management  Avoided / optimised investment  Greater self balancing ‘real’ time.  Aggregated balancing services  Demand BOAs  Avoided peak investment (observed and forecast reduction)  Contracted demand intertrip Potential from demand responsiveness (DSM)

21. Active distribution networks  Active management and control of distribution will become increasing beneficial given  Distributed generation  Electric vehicle charging  SMART appliances  Flexibility services required by  transmission system operator,  distribution system operator,  suppliers (balance responsible parties)  Service despatch must respect distribution network limitations

22. Future GB Networks: Potential New Developments  Series capacitors  Major Increase in HVDC interconnections (CSC & VSC) to external power systems (Ireland, mainland Europe)  Use of HVDC technology (CSC & VSC) embedded in GB synchronous power system  Multi-terminals HVDC systems onshore and offshore  Significant growth in new asynchronous generation technologies such as onshore & offshore wind and other renewables, as well as synchronous large nuclear, clean coal etc  Offshore ac and dc transmission networks as part of the GB power system

23. Future GB Networks: Technical Challenges (1)  Significant changes to the GB transmission system characteristics  New system design and operation solutions/technologies in GB introducing new phenomena that must be understood and any risks mitigated/managed  Fast control systems on series connected power equipment  Performance of many control systems independently and together (design, specification and testing) under continuously changing generation pattern/demand/network configurations

24. Future GB Networks: Technical Challenges (2)  System reliability as affected by the reliability of control systems used on series-connected equipment including their software and hardware  Adverse control interactions can cause large system impacts  First installations of Wide Area Measurement, Monitoring and Control (WAM M & C)?  All new controls must work with existing, conventional, fast and slow controls  All these network challenges are in addition to unprecedented changes in generation technologies

25. Potential R&D Areas (1)  GBSQSS review: Secured Event, boundary definition and boundary capability calculations  Interactions between HVDC and TCSC controls, mechanisms, mitigation etc  For asynchronous CSC or VSC HVDC links: are POD and large signal stabilisation controls technically feasible?  Technical feasibility of inertial (df/dt) response/control from asynchronous CSC and VSC HVDC links  Multi-infeed VSC HVDC

26. Potential R&D Areas (2)  WAMM&C in real time operation and pre and post fault power flow dispatch  Power system harmonics above 50 th ; effects of equipment and systems, emission limits for planning and compatibility  TSCS sub-synchronous characteristics, can it be made to look inductive? Laboratory model plus theoretical modelling and analysis  Multi-terminal VSC HVDC, DC faults and recovery

27. Electricity infrastructure – progress so far  A vision for the transmission network in 2020 produced  Preliminary engineering work commenced  Consultations and scrutiny of next network development steps underway  Planning Act passed  A range of revised Transmission Access rules developed. DECC consulting on use of legislative powers  An effective interim connect & manage regime delivering tangible results