Strengthening the Ghanaian transmission system to accommodate variable renewable energies

Abstract

In the light of economic growth in Ghana and the corresponding increase in electricity demand, power generation has been inadequate to meet the increasing demand. This has resulted in excessive pressure in the Ghanaian power system culminating in load shedding since 2012. As part of efforts to resolve the power supply deficit, construction of new generating units has begun, which are expected to come into operation within the year. These proposed generating units are mostly thermal and renewable energy units (predominantly wind and solar PV). The variable and intermittent nature of wind and solar PV (also known as variable renewable energies), introduce additional operational challenges in the power system. Against the backdrop of this challenge, questions arise on how the stability of the Ghanaian power system could be maintained especially as these renewable energy units are expected to be increased by the year 2020. In an effort to deal with this problem, the sole transmission system operator in Ghana, the Ghana Grid Company has proposed plans to reinforce the transmission system so as to accommodate the new generating units, especially the renewable energy units. This paper therefore reviews the measures being implemented to strengthen the Ghanaian transmission system. First and foremost, it identifies some of the expected technical challenges that may arise from the integration of renewable energies in Ghana's transmission system. The paper further presents the strategies being adopted to deal with the challenges and also discusses briefly the ‘Grid Optimization before Reinforcement before Expansion’ principle and proposes its adoption in the Ghanaian power system as an effective network planning strategy.