Kenya and Tanzania have invited bids for a consultant to oversee the construction of a high-voltage power line connecting the two nations, part of efforts to meet growing demand for electricity and deepen integration of their economies.

The two countries will build approximately 510 km of 400 kilovolt (kv) power lines and several substations to allow them trade in power.

The project is planned to be implemented in twenty-three months from the contract commencement date, a tender announcement published in the Daily Nation newspaper said.

The tender did not indicate the cost of the project. Bids are due by February 20.

READ: East Africa speeds up energy projects

Kenya is tapping geothermal resources in the Rift Valley as part of its broader ambition to add 5,000 megawatts (MW) to its electricity output by 2017. That will add to the country's existing capacity of about 1,664 MW.

As well as expanding generation, Kenya has plans to add 5,000 km of power lines to its existing 3,800-km network by 2017. Only a third of Kenya's 44 million people are connected to the grid, according to its energy ministry.

Kenya has at least 3,000 MW of proven geothermal energy in the Rift Valley, but exploits only about 200 MW, analysts say. It is currently adding 500 MW of geothermal capacity.

Neighbouring Tanzania aims to double its generation capacity to 3,000 MW by 2016.