Electrical Energy Transmission by High-voltage Direct Current (HVDC)

1. 18th APUA Congress Luanda, Angola, on 02-06 June 2014 General Theme  « The energy mix in Africa : challenges and prospects » Electrical Energy Transmission by High-voltage Direct Current (HVDC) and Prospects for an Electrical Market Mohamed Lakhdar HABIB and Rime BOUAROUDJ

2. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market Outline Introduction HVDC vs AC Configurations of HVDC systems Potential solar site in Algeria and Algerian transmission network Characteristics of Algerian SPTE Applications and results Maghreb interconnections Regional integration of a power market Maghreb - Europe Interconnections Conclusions and Prospects

3. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market Introduction • Why interconnections? • Security of provision and functioning • Economical use of resources and reduction in investment costs • Types of interconnections: • - Synchronous via alternative current (AC) systems • Asynchronous via direct current (HVDC or DC) systems • Areas where DC is used: • - Long distance transmission of the production of power plants to consumption centers • Integration of renewable energy generation systems into electrical systems • Interconnections of asynchronous networks • Submarine/ subterranean links for distances > 50 km.

4. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market HVDC vs AC HVDC AC No reactive effects, (unit power factor.). Easy interconnection of networks, suffice it to have the same voltage everywhere. No « skin » effect, the cables and lines are simple and inexpensive. Possibility of using transformers to increase and decrease voltage. Facilitates power shut-down by the natural passage by zero, twice per period (available circuit-breaker). Transmission and consumption of direct production by the alternators. Advantages VS Impossibility of voltage generation or increase in the field of very high voltage, hence the significant losses on lines. Difficulty of switching off direct currents, hence the need for better performing and expensive power shut-off devices. Very expensive terminations. Implies inductive and capacitive effects (power factor <1 mainly). The interconnection of several networks requires the identity of the voltage, frequency and the phase. Implies a «skin» effect, hence the necessity of adapted and more expensive cables and lines. drawbacks Each drawback of the AC system is met with an advantage of the HVDC system and vice versa

5. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market HVDC vs AC The cost per « km » increases according to distance, up to a certain distance (600 Kms) and the alternative current remains more economical. Beyond this, transmission via direct current becomes necessary. For the same level of redundancy, two (2) HVDC conductors equivalent to 02 three-phase lines.

6. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market Configurations of HVDC systems 2 1 Bipolar Unipolar 3 Back to Back Multi-terminals

7. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market Potential solar site in Algeria and Algerian transmission network

8. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market Characteristics of the Algerian SPTE Demand for electricity: 10 464 MW in 2013 at 40 600 MW by 2030, (8%) Generation system: 12 000 MW in 2013 at 50 000 MW by 2030, dont12 000 MW in renewable energy. Power network transmission : 02 levels of transmission voltage : 220 kV and 400 kV In 2013 : 4 500 km (11 000 km - 220 kV and 3 500 km - 400kV) 105stations (11 in 400/220 kV and 89 in 220/60 kV) By 2025: 31 400 km (20 000 km - 220 kV and 11 000 km - 400 kV) 245stations (45 in 400/220 kV and 200 in 220/60 kV)

9. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market Applications and results

10. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market Maghreb interconnections Morroco Algeria Tunisia Libya 2009-2010 1954 1980 1952 1984 1988-1992 • Technical and economic advantages of this interconnection : • instant power backup at each network in harsh situations • Reduction in generation cost by pooling the spinning reserve • Economies on investment • But: limited energy exchange Caption 400 kV 400 kV in project 220 kV 150 kV 90 kV

11. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market Regional integration of a power market • In Maghreb, several enabling factors • Functioning in interconnected networks for long years. • Trade with neighboring countries for more than 10 years. • ONEE and Sonelgaz are external operators on the Iberian electricity market (OMIE). • Availability of primary power resources, namely renweable energy. • Sustained growth of demand throughout the countries in the region.

12. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market Maghreb – Europe Interconnections

13. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market Conclusions and Prospects • Existence of a basic infrastructure to launch a Maghreb power market • Massive development of renewable energies in Maghreb, an additional factor towards the establishment of a Euro-Maghreb power market. • Construction of important links possibly in direct current to transmit solar energy from the South to the North of Algeria • Construction of submarine links between Maghreb countries and Europe in view of a Euro – Maghreb power market • Pursue efforts to remove institutional and legislative barriers relating to the implementation of a power market.

14. Electrical Energy Transmission by HVDC Networks and Prospects for an Electrical Market Thanks for your kind attention www.sonelgaz.dz