AfDB backs $282m Tanzania islands power line

From the newsletter

The African Development Bank (AfDB) has approved $282 million for an undersea power transmission line connecting the three offshore Zanzibari islands. This will increase power capacity from 143 MW to 440 MW, enough to connect 465,000 new households and contribute to Tanzania’s goal to increase electricity connectivity to 75%  by 2030.

• Power transmission lines have received increased financing over the past couple of years. The AfDB has funded at least four power transmission line projects since the start of 2025, including the $292 million Zambia-Tanzania interconnector.

• Tanzania’s ageing and inadequate grid infrastructure, as per its Mission 300 National Energy Compact, requires an estimated $1.4 billion for rehabilitation and $6.4 billion for grid expansion. The AfDB project is a vital, but partial, contribution toward this goal.

More details

• The project is set for completion over five years, with submarine power cables constructed to Unguja, Pemba, and Mafia islands, as well as distribute 335,300 clean cooking appliances.

• According to Patricia Laverley, the AfDB Country Manager for Tanzania, it will boost youth-led Micro, Small, and Medium Enterprises (MSMEs) and is also considered vital for the development of Zanzibar’s tourism sector, which accounts for approximately 30% of the island's GDP.

• Transmission lines and grid expansion are fundamental to achieving 100% electrification across Africa. As of 2025, only a fraction of the continent enjoys reliable access to electricity, with infrastructure bottlenecks and underinvestment standing as key barriers. 

• Governments must create clear policy frameworks to attract private investment in transmission lines, which have traditionally been a state-owned monopoly. By doing so, they can leverage private capital to bridge the massive financing gap. Policies that de-risk projects, offer stable returns, and streamline regulatory processes are crucial.

• Several African nations are pioneering this shift. South Africa has opened its grid infrastructure to private sector investment, targeting the construction of 14,000 km of power lines by 2035. It has already issued a Request for Qualification (RFQ) phase for its Independent Transmission Programme (ITP), seeking to pre-qualify bidders with the necessary technical and financial capacity. Kenya, meanwhile, is pursuing transmission line expansion through a public–private partnership with Africa50.

• Submarine power transmission is especially vital for island electrification in Africa, where off-grid solutions often fall short due to scale and intermittency. Projects in Mauritius and Madagascar have demonstrated the effectiveness of submarine cables in enhancing power reliability, reducing dependency on expensive diesel generation, and enabling integration with mainland grids.

Our take

• The AfDB's investment recognises that building a stronger grid is about fueling the economy, empowering communities, and protecting the environment all at once. By combining new power lines with new connections and clean cooking solutions, this project tackles multiple challenges with a single, smart strategy.

• Getting the cables in the water is just step one. To ensure this investment pays off for generations, Tanzania must prioritise flawless maintenance and local expertise. A well-trained workforce and a solid operational plan are the secret ingredients that will keep the lights on and the benefits flowing for decades to come.

• This project sets a standard for how we approach development. Instead of tackling one problem at a time, it shows that a truly holistic, long-term vision is the key to unlocking Africa's energy potential. The rest of the continent should be watching and learning.