The coming online of West Africa’s first hydro-solar plant in late 2022, is expected to put Ghana on track to cut its power sector greenhouse gas emissions (GHG) by 235,000 tons per year.

The construction of the power plant which receives technical support from the United States Agency for International Development (USAID) and the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), adds to Ghana’s renewable energy drive.

As energy demand increases in Ghana, with demand forecast to rise to 3,545.27MW, representing 9.2 per cent growth, the government is seeking to diversify the country’s energy mix.

The use of innovative ways to integrate variable renewable energy (VRE) into its national grid— particularly wind and solar— are helping the country reach its target emissions goals, shift away from fossil fuels, supplement hydro resources during drought periods, and lower energy costs.

The project which kicked-off following a collaboration between USAID’s WAEP, NREL and BPA was to operationalize the first 50 MW of Photovoltaic (PV) within the existing Bui Generating Station hydroelectric dam site in 2021, with plans to grow PV capacity to 250 MW.

Scheduled for completion by late 2022, the plant will also contain a 20-MW-hour battery energy storage system and controls, which the NREL team suggested so the plant can meet existing grid codes for renewable energy resources, manage the variability of solar, and increase the country’s power sector reliability.

This new capacity will provide enough energy to power an estimated 200,000 households and allow BPA to gain valuable experience in developing more solar energy projects.

Peter Acheampong, Deputy Director of renewables at Bui Power Authority (BPA) said:

“The global challenge of climate change, as well as the need to secure energy supply, makes the development of the hydro-solar plant very important for Ghana and West Africa.”
Peter Acheampong

Maintaining Steady Power Supply

The addition of PV to the hydro plant allows BPA to balance the variable output of solar by simultaneously increasing or decreasing hydro power output in real-time to maintain a steady power supply to meet demand, including the addition of new controls and capabilities to effectively manage output.

NREL worked closely with BPA’s renewable energy manager to provide in-depth analysis of the impacts of such hybrid hydro-PV operation, and the institutional, operational, and hardware changes required to ensure the proposed system can operate in a hybrid manner while maintaining system stability and reliability.

In parallel, NREL worked with Ghana Grid Company Limited, the system operator and transmission asset owner, to better understand the potential operational impacts of interconnecting BPA’s hybrid system.

David Corbus, the Wind Grid Integration Lead at NREL and a member of the NREL-WAEP team supporting the Ghana solar project, said:

“We are equipping them with all the tools and lessons we learned in the United States about VRE integration, and, in some cases, helping them to avoid some of the challenges we had with the latest technology and standards. Having this type of partnership is an effective way to streamline the process of integrating advanced technologies.”
David Corbus

The first 50 MW of the plant generates energy onto the national grid during the day, with 1 MW of the installed system consisting of floating solar PV. On the whole, the hydro-solar hybrid installation provides a platform for Ghana to harness its immense solar resources, combat low water levels during the dry season, and provide grid operators more flexibility to run the hydropower plant at night.