Integration of variable renewable energy in the national electric system of Ethiopia
- Supervisor: Luca Marena, RES4Africa
- Ulderico Bagalini, Bruno Cova, Andrea Prudenzi, CESI – Leonhard Braun, Daniele Paladini, RES4AFRICA – Tesfaye Batu, Daniel Mulatu, Bizuayehu Tesfaye, Mulat Azene, Melaku Yigzaw, Estifanos Gebru, Ethiopian Electric Power – Mirko Armiento, Giuseppe Montesano, Enel Foundation
Access to the complete article : https://bit.ly/30lcFSB
Published at : February 2019
The objective of this activity addresses the integration of variable renewable energy sources (VRES) such as wind and solar into the Ethiopian electric power system. Increasing penetration of wind and photovoltaic technologies has been analysed in the mid- and long-term (horizon years 2025 and 2030) considering the reliability, integrity and efficiency of the electric power system.
The Government of Ethiopia (GoE) focuses on the electricity production from renewable energy sources (hydro, geothermal, wind, solar and biomass) to develop a cheap and clean energy mix for a sustainable development of the energy sector. As highlighted by the Ministry of Water, Irrigation and Electricity (MWIE) in the Ethiopian National Electrification Program, the GoE is focused on diversifying its energy mix with wind, solar and geothermal sources to complement the large base of hydro resources development. A diversified mix of energy resources allows ensuring the security of supply and contributes to mitigate climate change, in line with pillar three of Ethiopia’s 2011 “Climate Resilient Green Economy (CRGE) Strategy”, which requires 15-20% of the energy supply to come from nonhydropower based renewable resources by 2020.
Ethiopia has very good amount of clean and diversified energy resources; the identified potential includes 45 GW from hydropower, 7 GW from geothermal power, 1,350 GW from wind power and 5.5 kWh/m2 /day (annual average daily radiation) from solar source . Ethiopia plans to exploit these resources to meet the growing internal demand and increase the export of clean energy towards the neighbouring countries. The achievement of GoE’s development vision to assure a reliable electricity access for all will allow a great increase of the national demand: CAGR 12.5% is expected for the domestic electric consumptions in the period 2017-2030 . However, the exploitation of the big renewable energy potential shall be accompanied by the fulfilment of the current and future international interconnections which are a key strategic driver to exploit the Ethiopia’s advantage as a cost competitive exporter of power to the higher cost regional power markets (mainly to Sudan, Djibouti, Kenya and Tanzania). The GoE’s strategy is to become a world class exporter of large amounts of clean and cheap renewable energies.
The existing power generation capacity is about 4.3 GW. Hydropower plays an important role in the existing Ethiopian generation fleet (about 89% of total installed capacity is from hydropower) and it will continue in the future; in fact, an important water resources exploitation plan is ongoing (e.g. 6,000 MW Grand Ethiopian Renaissance Dam is close to be completed). Wind power is already today the second electricity source of the Country (8% of total installed capacity).
In this context an exploitation plan of additional wind and photovoltaic capacity could lead to several benefits for the system. The first one could be a bigger export towards the neighbouring countries where the electricity price is higher. Furthermore, a different hydropower planning could be developed in the long-term, anticipating wind and solar investments. In this way, water could be exploited also for sectors other than electricity (e.g. agriculture, household consumptions, etc.) keeping, at the same time, the goal to increase the renewable energies in the Country. Moreover, a better water exploitation during the year is possible thanks to the complementarity of wind and solar sources with hydro sources; wind and solar radiation are greater during the dry season and lower during the wet season when more water is available for hydropower.
Wind and photovoltaic integration could allow additional technical-economic benefits as a faster commissioning of new capacity with more opportunities for Independent Power Producers (IPPs) investments, new opportunities for the Ethiopian manufacturing and service sectors, decentralization of the power supply structure thanks to their availability in different regions of the country (more diffuse than other big power plants in the pipeline) and a more constant growth of the generation year by year.
The Ethiopian renewable energy potential, together with the decreasing levelized cost of electricity (LCOE) from wind and photovoltaic technologies (competitive in the long-term with the cheapest technologies) will allow attractive perspectives for private investors. Technical investigations are needed to identify possible criticalities both about the power system operation and about the network reinforcements necessary for the integration of new VRES power plants in accordance with the security criteria adopted by the system operator.
CESI, as an active member of RES4AFRICA association, supported RES4AFRICA to carry out the technical analyses for a secure and reliable operation of the Ethiopian electric power system in presence of VRES power plants and identify the best connection options and the necessary network reinforcements for their best integration.
CESI, in particular, with the collaboration of the Ethiopian Electric Power (EEP) Company and RES4AFRICA carried out a pre-feasibility study including market-based analyses and a preliminary network impact study, based on the system adequacy and the grid loadability, to achieve the following specific objectives, which collectively form the basis of the scope of work:
- Provide an assessment of the maximum amount of VRES generation (wind and PV) that is possible to integrate in the Ethiopian electricity network ensuring the reliability, integrity and efficiency of the power system;
- Execute reliability and market-based analyses, with an optimal coordinated hydro-thermal scheduling of the generation fleet, to assess the benefits related to wind and solar energy integration:
- increasing energy export;
- interaction between hydropower and VRES generation during the year;
- security of supply during low rainfall periods;
- possible review of water management strategy to increase the access to safe water for all Ethiopians and the food production to meet internal demand.
- Evaluate the adequacy of the transmission system integrating new wind and PV capacities and propose, if any, network reinforcements needed to maximise their exploitation.
Furthermore, qualitative considerations on system resilience improvement in presence of extreme events have been included in the study, together with additional observations about the benefits of innovative VRES power plants control to better exploit resources.
The RES4AFRICA study started from the least costs generation and transmission expansion plan defined by EEP and increased the amount of wind and PV generation in the Ethiopian system exploiting as much as possible the exchange capacity with the neighbouring countries.