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The Project

Zanzibar is completely reliant on electricity supply from mainland Tanzania. The existing interconnector came to the end of its useful life expectancy and suffered from a series of breakdowns.  

The Millennium Challenge Corporation funded a second 100 MW interconnector to provide a long-term, modern and reliable supply to the island. 

Responsible for electricity generation, transmission and distribution on mainland Tanzania and Zanzibar are Tanzania Electric Supply Company (TANESCO) and Zanzibar Electricity Corporation (ZESCO).

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Our Approach

  • The Challenge

    Managing the successful delivery of a 132 kV interconnector including a 37 kilometre single submarine cable traversing a sensitive marine environment, overhead line construction in dense urban areas and substation interconnector components.

  • The Solution

    ESB International acted as owner’s engineer, and project managed all aspects of the interconnector from mainland Tanzania to Zanzibar. There was significant co-ordination between the implementing the utilities TANESCO and ZESCO and Contractors to ensure timely completion of submarine cable, overhead line and substation interconnector components.

What we delivered

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Best practice project and contract management to deliver: 

  • 132 kV, 100 MW 3 core (copper), cross linked polythene submarine cable from Tanzania to Zanzibar. 
  • Total of 39 kilometres of 132 kV of overhead line in Tanzania and Zanzibar.  
  • New and extended 132 kV substations.


The Results

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  • This project secured long-term electricity supply to the island nation. 
  • Increased interconnector capacity to 100 MW allowing ZESCO grow their customer base 
  • Overall development in the island and a reduction in utility costs. 

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Contact Us

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