Aerial view of a 50 MW solar PV power plant, with an additional 200 MW in development. Photo courtesy of BPA.
The first West African hydroelectric power plant was deployed in Ghana in January, with technical support from the United States Agency for International Development (USAID) and the US Department of Energy’s National Renewable Energy Laboratory (NREL). When its full capacity is up and running, this hydropower plant will put Ghana on track to reduce greenhouse gas emissions in its energy sector by 235,000 tonnes a year.
As energy demand increases in Ghana, its government is seeking to diversify the country’s energy mix and find innovative ways to integrate variable renewable energy (VRE) into its national grid – especially wind and solar – to meet its emission targets, moving away from fossil fuels, replenish hydro resources during drought periods and reduce energy costs.
David Corbus, NREL, and Peter Acheampong, BPA, visit NREL’s Flatirons Campus. Photo by David Corbus.
To support this effort, in 2017 the USAID-NREL Partnership facilitated talks with the Ghanaian Bui Power Authority (BPA) at a workshop organized by NREL that focused on the capabilities of advanced photovoltaic (PV) plants, solar and wind power integration, and best practices in integrating small-scale and utility VREs into the Ghana network. Following the workshop, BPA called on the NREL team to provide additional technical assistance to support BPA by adding solar PV energy to an existing 400 megawatt (MW) hydropower plant to reduce greenhouse gases, increase hydropower and provide energy diversity.
Building on these discussions, USAID’s Power Africa West Africa Energy Program (WAEP) and NREL have partnered with BPA to operationalize the first 50 MW PV within the existing Bui Generation Station in 2021, with plans to increase PV capacity to 250 MW . Planned to be completed by the end of 2022, the plant will also feature a 20 MW-hour battery storage and control system, proposed by the NREL team to enable the plant to meet existing renewable energy grid codes, manage solar variability and increase the reliability of the country’s energy sector.
This new capacity will provide enough energy to power about 200,000 households and enable BPA to gain valuable experience in developing multiple solar energy projects.
“The global challenge of climate change, as well as the need to secure energy supplies, makes the development of a hydro-solar power plant very important for Ghana and West Africa,” said Peter Acheampong, BPA’s Deputy Director of Renewable Sources, who worked closely with NREL-WAEP. .
Construction of PV installation
Since 2017, the NREL-WAEP team has hosted workshops, provided technical analysis, reviewed the impact on the network and stability studies for the plant, modeled the energy flow for transient events and evaluated the plant design to ensure compliance with Ghana’s new GRE network codes . They also offered guidelines on photovoltaic technology on a communal scale and worked closely with stakeholders and industry groups in Ghana to review best practices for the operationalization of this large VRE plant. In addition to working with BPA and the Volta River Authority (VRA, Ghana’s Second Electricity Authority), the NREL-WAEP team collaborated with sectoral agencies, including distribution companies, transmission companies and independent electricity producers, to conduct analytical studies and impact assessments outside the Bui Solar Project. .
BPA technicians and control room operators are monitoring the output of the new photovoltaic system. Photo by David Corbus, NREL
The addition of PV to the hydropower plant allows BPA to balance the variable power of solar energy while increasing or decreasing real-time hydropower output to maintain a stable power supply to meet demand, including adding new controls and efficient output management capabilities. NREL worked closely with BPA’s Renewable Energy Manager to provide an in-depth analysis of the impact of such hybrid hydro-PV operation, and the institutional, operational, and hardware changes needed 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 owner, to better understand the potential operational impacts of the interconnection of BPA’s hybrid system.
“We equip them with all the tools and lessons we’ve learned in the United States about VRE integration, and, in some cases, help them avoid some of the challenges we’ve had with the latest technology and standards. This type of partnership is an effective way to simplify the process of integrating advanced technologies, ”said David Corbus, head of NREL wind farm integration and a member of the NREL-WAEP team supporting the solar project in Ghana.
This project represents a major step forward in West Africa’s efforts to integrate a larger share of renewables into its regional energy mix. As Ghanaian President Nana Akufo-Addo said in a speech read on his behalf, “This further demonstrates my government’s commitment to fulfilling its promise to increase the renewable energy component in our energy mix to 10 percent by 2030.”
The first 50 MW of the power plant produces energy into the national grid during the day, with 1 MW of installed system consisting of floating solar PV. Overall, the hydro-solar hybrid installation allows Ghana to harness its vast solar resources, tackle low water levels during the dry season and give network operators more flexibility to run the hydropower plant at night.
Exploring Rooftop Solar
In parallel with the large utility PV installation, the NREL-WAEP team also supports the implementation of decentralized photovoltaic modules in Ghana, enabling consumers to take advantage of rooftop solar energy savings. The team provides electricity distribution companies with the tools they need to understand and plan for distributed photovoltaics, identify the financial impact on utilities and consumers under different scenarios, and quickly assess the benefits and challenges of capacity analysis and solar installations for new customers.
“We worked with Elektroprivreda Gana and the Northern Electricity Distribution Company, where we passed on open source software and gave them training, capacity building and workshops with utility engineers where we assessed plans and looked at studies for integrated distributed PV,” Corbus said. about Gana’s team’s contribution to planning photovoltaic energy behind the meter.
Part of the training included completing a utility revenue impact analysis and tool development training, which assesses how PV affects construction models, cash flow and revenue. The team is also working with the Public Enterprise Regulatory Commission and the Ghana Energy Commission to clarify the results, answer questions and challenges for distributed PV planning and translate the results of the analysis into policy.
The Ghanaian photovoltaic system will be controlled together with a 10 MW battery system and coordinated with a 400 MW hydro system. Photo by David Corbus, NREL.
The Road Ahead
The Bui Hydro-Solar Hybrid project is a historic leap towards a more sustainable future for Ghana and West Africa, paving the way for more renewable energy technologies across the continent, serving as a model for future hybrid power plants and demonstrating how inter-agency collaboration can accelerate programmatic results and enable future partnerships.
“Through social pressure towards sustainable clean energy, I hope that a total of 60% or more of the energy delivered to the national network is from renewable energy sources. “Although it may be on the higher side because Ghana is a developing country and we could be limited to some uncontrollable factors, with the right mentality, we can do our best to make this dream or hope a reality,” Acheampong said.
But we have a long way to go: more than half of sub-Saharan Africa still lacks access to electricity. The NREL-WAEP team continues its work on bringing clean, affordable and affordable energy to the region, overcoming intercultural and geographical barriers to address common implementation goals and provide innovative and reliable energy solutions.
Learn more about USAID-NREL Partnershipsee USAID Power Africa programor read about how USAID WAEP provides reliable and affordable electricity for West Africa.
Emily Klos. Courtesy of the National Renewable Energy Laboratory (NREL) of the US Department of Energy (DOE).
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