Efficient Energy Transmission using HVDC ENERGY EFFICIENCY IDB SÃO PAULO – SP 15 September2008 Welcome Efficient Energy Transmission using HVDC John Graham john.graham@br.abb.com

Why transmit electric energy? To connect generation to load. To optimise generation prices within the market. To increase the firm energy in hydroelectric systems. Why transmit electric energy with HVDC? More efficient. More robust. Less environmental impact. Smaller Right of Way 2 conductors vs 3

Hydraulic Basins Why transmit electric energy? To connect generation to load. To optimise generation prices within the market. To increase the firm energy. In order to be efficient the transmission should have minimum electrical losses.

In order to be efficient the transmission should have minimum electrical losses. Losses = I2R, Square of the Current. Increase the voltage in order to reduce Current. Long distance and/or high power tends to favour higher voltages.

Basic Considerations : Voltage Level Comparison between HVAC and HVDC shows similar behaviour. The maximum voltage stagnated due to market reasons. Now the market has changed! Lower losses Less lines More efficient Voltage Level HVAC e HVDC Basic Considerations : Voltage Level

Chinese system planning for 2012 Three HVDC links in 800 kV in construction 3 x 2000 km. Power to 7200 MW. 650 km of 1000 kV Three GIS stations Chinese system planning for 2012 State Grid of China

Renewable EnergyAlternatives Biomass All require transmission both efficient and flexible Wind Solar Hydro Sol

Europe: Renewable Energy Vision Hydro power Solar power Wind power DC transmission Wind 300 GW 25 000 km sq 5000 x 10 km Hydro 200 GW Europe Europe: Renewable Energy Vision

EON Netz, NordE.ON 1, 400 MW HVDC Light 400 MW off shore converter 128 km sea cable 75 km land cable 400 MW converter EON Netz, NordE.ON 1, 400 MW HVDC Light

International exchanges Challenge to integrate long distance interconnections. ▲ ▲ ▲ Wind Power 5000 MW Future Hydro generation ▲ ▲ 1000 km Hydro generation: Long distances Thermal: Close to the loads Wind power: North coastal International exchanges CCGT Coal

Why transmit electric energy? To connect generation to load. To optimise generation prices within the market. To increase the firm energy in hydroelectric systems. Why transmit electric energy with HVDC? More efficient. More robust. Less environmental impact.

Market today Efficiency Environment Reliability Market tomorrow Drivers Drivers Efficiency Environment Reliability Market tomorrow

Number of lines in parallel to transmit 7000 MW 500 kV ac. RoW 5 x 80m = 400m 2000km = 800km2 800 kV ac. RoW 3 x 100m = 300m 2000km = 600km2 600 kV dc. RoW 3 x 75m = 150m 2000km = 300km2 800 kV dc. RoW 1 x 80m = 80m 2000km = 160km2 The information in the table on the previous slide has been illustrated here to give an impression of the right-of-way requirements and environmental impacts for different transmission capacities and system voltages. The effectiveness of HVDC transmission lines at higher voltage levels is clearly demonstrated. Less clearing of forest to prepare Right of Way

La HVDC conserva bosques y terrenos Cables HVDC La HVDC conserva bosques y terrenos La corriente directa require menos líneas para la mísma potencia La corriente alterna require corredores anchos

Why use HVDC Transmission? 1. Lower investment costs 2. Long Distances 3. Lower electrical losses 4. Asynchronous interconnections 5. Flexibility by control 6. Limitation of sort circuit currents 7. Lower environmental impact It can be seen that all these Reasons are applicable in Brasil

Itaipu 2x7000 MW 3 EHVAC Lines 2 HVDC Lines 765 kVac About 70% Guyed Vee Average weight 8500 kg 16 m Phase spacing Conductor 4xBluejay 564 mm² 35 Insulators 2 HVDC Lines ± 600 kVdc About 80% Guyed Mast Average weight 5000 kg Conductor 4xBittern 644 mm² 32 Insulators 510 mm creep 16 m pole spacing Here Itaipu shows us the economy in transmission lines obtained by the use of HVDC.. ABB Scope of Work: Tower engineering for both lines. Tower supply and construction for large part of both. Commercial operation in 1984 Today still the highest voltage in HVDC

Foz do Iguaçu Converter Station

HVDC systems in North America Asynchonous borders Canada - USA HQ – NEPOOL In a mature power system, in this case North America, Between synchronous areas Generation connection Interconnection Asynchronous Interconnection Generation Outlet Interconnection HVDC systems in North America

HQ – NEPOOL Multi-terminal Corrente Continua em Multi-terminal HQ – NEPOOL Multi-terminal Technical Data: Commissioning year: 1990-1992 Power rating: 2000 MW (multiterminal) DC voltage: ± 450 kV Length of overhead DC line: 1480 km Main reasons for choosing HVDC system: Asynchronous link Multi-terminal example: Hydro Quebec – New England

Blackout Aug 14, 2003 Source: Public Power Weekly, August 25, 2003 200 MW 500 MW 147 MW Blackout Aug 14, 2003 Source: Public Power Weekly, August 25, 2003

Interconnection of the Rio Madeira generation HVDC RoW 150 m or 350 km2

Interconnection of the Rio Madeira generation Hybrid RoW 235 m or 560 km2

Hydroelectric expansion 2007 - 2016 N – S IV Tocantins Wind Power 5000 MW Belo Monte ▲ ▲ ▲ ▲ ▲ Tele Pires 1000 km Das Mortes Energy exchange is facilitated by the flexibility of HVDC. More security with control avoiding cascade tripping. Lower environmental impact due to reduced RoW. Rio Madeira Taking the flows Sul - SE Future CCGT Hydroelectric expansion 2007 - 2016

Why transmit electric energy? Reasons to use HVDC links in Brasil 1. Lower investment cost 2. Long distances 3. Lower losses 4. Asynchronous interconnections 5. Flexibility by control 6. Limitation of short circuit currents 7. Lower environmental impact Why transmit electric energy? To connect generation to load. To optimise generation prices within the market. To increase the firm energy in hydroelectric systems. Why transmit electric energy with HVDC? More efficient. More robust. Less environmental impact.