Renewable energy investment company Blue Energy said construction of the Nzema project in Ghana is due to start within 12 months and will cost $400 million.
It will be the most ambitious of dozens of photovoltaic power plants being considered across Africa, an industry analyst said.
"It is the biggest single project that's going ahead at the moment," Ash Sharma at IMS Research told BBC News. "It is not the biggest in the world, but if it goes ahead it will be the biggest in Africa."
The characteristics and availability of sunlight at the Ghana site are favorable for a photovoltaic power plant, said project director Douglas Coleman of Mere Power Nzema Ltd.
"We can predict with great certainty on an annual basis, the output from the plant," he said. "That predictability means we can harmonize with the needs of the transmission network, to balance load with generation."
Huge drops in the price of solar panels will help make the project viable in an emerging economy like Ghana, analysts said.
"The reason the technology hasn't taken off so far is that it has been too expensive," Sharma said, "but the costs of solar [panels] have decreased dramatically in the last two years, they've fallen by 40 percent plus, and this has really enabled it to be used in emerging regions in Africa and Asia."