Energy security and supply in the Economic Community of West African States (ECOWAS) are threatened by various factors including limited infrastructure, fuel import dependence, and heavy reliance on fossil fuels, hydropower, and traditional biomass resources. Projected climate change impacts in the region will likely further affect the electricity supply and market. In the coming years, rising energy demand due to population growth, rapid urbanization, and economic development will place additional strains on the region’s electricity system. Renewable energy technologies can play an increasingly important role to meet these challenges and the objectives of the Paris Agreement on Climate Protection. That is why, as soon as 2009, ECOWAS established ECREEE (ECOWAS Regional Centre for Renewable Energy and Energy Efficiency) to meet the lack of access to energy services and to support climate change mitigation. ECREEE’s mission is the regional energy planning and via the National Focal Points, to support and advice the countries to ensure that national minimum renewable energy targets are adopted and achieved in all ECOWAS Member States. As the share of renewable energies in the energy mix grows, forecasting the electricity generation as well as the electricity demand is becoming increasingly important. Moreover, a massive deployment of renewable energy will increase the complexity to manage the electricity system due to their variable and intermittent nature, from sub-daily to multi-decadal timescales. There is thus a demand for predictions ranging from weather forecasts for the next hour to monthly and seasonal predictions and climate predictions and projections. While efforts have been made in Europe to integrate climate information and services in the decision making process in the energy sector, such dedicated services in West Africa are nascent. Providing climate services to regional stakeholders taking into account their knowledge and needs could support a more sustainable development of the electricity sector and thereby, reduce the economic, social and environmental vulnerability. Therefore, the general objective of ERACSES is to deliver climate services to support the use of an optimized mix of Variable Renewable Energy (VRE) sources under various scenarios of transmission grid, backup and demand at regional and national levels. This project will be implemented at two levels. At regional level (West Africa), a Regional Climate Services Information System for Energy Sector (Platform ERACSES) will be installed at ECREEE to support VRE energy planning and policies. This platform will be built upon the C3S ECEM Demonstrator (developed to improve assessment of energy mix options over Europe with a set of tools and an online web interface), which will be powered with tailored co-developed products and services to enable the electricity companies and policy makers to assess how well energy supply will meet demand in West Africa and how energy supply and demand are sensitive to climate in different time horizons. At national level, it will focus on Côte d’Ivoire where a National Platform of Climate Services for the Energy Sector (named Platform ERACSES-CI) will be installed in the National Meteorological Office (SODEXAM) to support the management of electricity and of hydropower in providing climate information and services to a committee of electricity companies in Côte d’Ivoire including the National Focal Point of ECREEE to ensure the links between the two levels. For both the regional and the national scales, the integrated modelling approach Climate, Land-use, Energy and Water strategies (CLEWs) will be applied to investigate interconnections between these different energy resources and to identify counter-intuitive feedbacks in these integrated systems, in particular with regard to demand scenarios.