1. The Integration of Renewable Energy onto the Existing Grid Dr Norman MacLeod Technical Director, HVDC

2. Run of the river schemes use the natural force of the water to turn the turbines Minimal environmental impact Dams create a head of water which turns the turbines Significant environmental impact Micro-hydro generation Diverting water from local streams Connected to the local community Hydro-electric Power

3. On-shore wind farms are typically 10 – 50MW Turbines typically up to 3MW rating Connected at distribution voltage level Wind Power Off-shore wind farms are typically up to 600MW (AC connected) and 1200MW (DC connected) Turbines up to 8MW Connected at transmission voltage level

4. Domestic Connected to the low voltage distribution grid Supplies local loads and any excess is fed into the distribution grid Commercial Photovoltaic panels generate electricity at low voltage DC Conversion from DC to AC is needed for connection to the transmission grid Solar Power

5. Other sources Wave power – in development Tidal power – barrage schemes in use Tidal power – submerged turbines in development Bio-mass – in use as a coal replacement Electric vehicles – both a load and a generator Renewable Energy Sources

6. Intermittency of power generation Remoteness of power sources from load centres Impacts on system stability - Loss of inertia on the network – closure of rotating plant Harmonic distortion – Irish Grid Code Low voltage ride-through – Irish grid Code The Issues

7. Diversity of power sources Fossil fuels + renewables Grid enhancement AC transmission lines and/or HVDC embedded links HVDC interconnectors to neighbouring grids (UK, France) Dynamic reactive power devices SVC or STATCOM Harmonic filters Passive and/or active Advanced power electronic controllers “Synthetic inertia” Storage systems The Solutions

8. Off-shore Wind Farm (AC) Source : Alstom Wind Turbines AC Collector Platform On-shore sub- station Submarine cable

9. STATCOM Source : Siemens Greater Gabbard off-shore wind farm, UK Control of reactive power flow Low voltage ride through Harmonic distortion System stability

10. HVDC Transmission t i Iac t i t Idc i

11. East West Interconnector (EWIC) Source : EirGrid AC DC AC DC AC S/S Woodland Converter Station Shotton Converter Station 45km181km34km EirgridNational Grid ±200kV XLPE Cables

12. Woodland Converter Station Source : EirGrid Exterior view of converter stationInterior view – converter hall

13. Ireland HVDC Schemes Existing Interconnectors Future interconnectors Embedded links

14. The Existing AC Grid

15. The Grid of the Future? AC DC 110 kV 400 V 10 kV 400 kV 400 V 10 kV 35 kV Offshore wind farm 150 kV Bulk power import using HVDC 320 kV AC DC AC DC AC DC 50 kV DC AC DC 500 V Electric Vehicle Charging Station station AC DC AC 10 kV AC DC AC 500 V Battery Energy Storage System Photo Voltaic DC Power Cells

16. High levels of renewable generation can result in significant issues on the existing AC network Smart grid solutions can be used to support and manage integration of renewable energy sources Smart Grids = Power Electronics + Automation Systems Conclusions

17. Any questions? Tormoid Mhic Leòid