Mount Coffee hydropower plant: Raised from the ruins

With undeveloped reserves of about 400GW¹ Africa has the potential to meet much of its growing demand with hydroelectricity. Currently only 37GW² of installed capacity are being used, and in 2019 about 580 million Africans³still had no access to electricity. So could hydro – plentiful, sustainable, clean – provide the baseline capacity the continent needs to power its homes and growing economy? 

German hydropower company Voith thinks so. In May 2012, alongside the state-owned Liberia Electricity Corporation (LEC) and other partners including Hydro Operation International (HOI), it started the rehabilitation of the Mount Coffee hydroelectric power plant in Monrovia, the Liberian capital. 

Energy boost

When reconstruction was completed at the end of 2016, Mount Coffee added 88MW to Liberia’s energy supply, providing about 1 million people⁴ with a stable electricity supply and replacing some of the country’s more expensive and unecological diesel generators.

“The Mount Coffee project has quadrupled Liberia’s installed capacity and established a really strong and stable backbone for the grid,” says Voith’s Chief Operating Officer Tobias Keitel. “Therefore it has also provided a base for the further rebuilding of the country’s economy.”

Speaking at the plant’s inauguration, then-President Ellen Johnson Sirleaf agreed, describing the reconstruction as “an important step in the fight for the development of the Liberian economy and combating national poverty”. She also said that the additional capacity had helped to bring down electricity prices in Liberia – previously the highest in the world – by nearly 10%.⁵ 

Road to success

Restoring Mount Coffee was not easy. Built in the 1960s on the Saint Paul River as Liberia’s largest hydropower plant, it had been looted and flooded since its destruction during the 1990s.

The reconstruction teams on the ground had to contend with a difficult-to-reach location served by poor roads that became even worse during the wet season, the Ebola outbreak in 2014 and bouts of malaria. During the Ebola epidemic, the plant components were stored in locations around the world, ready to be shipped to Liberia when it was safe to do so. Despite these challenges, the overhaul was completed on time in December 2016, and the plant is now about to be linked to the regional West African grid, strengthening grid reliability in the region.

A tech makeover

The redevelopment kept the plant’s 60-year-old structure, reinforcing it and replacing the existing equipment with modern technology. Along with new generators and digital systems, four Voith turbines were installed, increasing pre-war output from 64MW to 88MW. 

“We have the most modern technology of any power plant in West Africa,” says Emile G. Karnga, the plant’s manager. “The only thing that remains unchanged from the original plant is the structure. Everything else is state-of-the-art technology.”

Equipment and design specifications had to consider both the new turbines being installed and the 60-year-old superstructure. To do this, Voith and LEC used 3D construction technology, and established a workshop on site to pre-assemble equipment before it was installed.

Knowledge for the community

In 2016, HOI was contracted for the span of five years to operate and maintain the power plant, and to train the Liberian staff to take over at the end of 2021.

The project also emphasised knowledge transfer and the training of the Liberian staff who run the modernised plant, through Voith’s HydroSchool programme in Liberia and Germany. Engineers from LEC, including Karnga, travelled to Kafue Gorge Regional Training Centre in Zambia and to Voith’s headquarters in Germany for training. Classroom sessions were followed up by hands-on demonstrations at the plant. 

Now, the plant has been affected by another disease. The Covid-19 pandemic has forced this training online, and the first fully virtual HydroSchool session took place in November 2020. 

HydroSchool is designed to ensure optimum plant performance, but it is more than that. “It is an important component for the cultural and economic exchange with Liberia,” says Voith’s Tobias Keitel. And even without this important training programme, Mount Coffee itself would benefit the local area. “Hydropower is the renewable technology with the highest local value creation,” adds Keitel. “Because most of the electromechanical scope and of course the civil works must be done on-site.” 

Power base

LEC now plans to expand Mount Coffee. First, by creating a reservoir upstream that will improve management of the river flow through the dam as generation slows during the dry season. Next, a different kind of renewable energy: a feasibility study for a 90MW solar power farm nearby has now been completed.

“Hydropower plants are the backbone of a renewable generation portfolio,” says Keitel. “Because hydropower has the ability to be the baseline for a stable grid that solar and wind feed into.”

This means Mount Coffee could be the start of an electricity generation hub capable of supplying Liberia well beyond Monrovia – and, using the West African grid connection, even further afield. That is big news for Africa’s power supply.

Mount Coffee facts:

• Cost: $357 million⁶
• Funded by the Liberian and Norwegian governments, the European Investment Bank, German development bank KfW, and the Millennium Challenge Corporation
• Total installed capacity: 88MW, up from 64MW before the plant’s abandonment
• Provides electricity for about 1 million people
• Has helped to bring down Liberia’s electricity price – previously the highest in the world