Vandalism of a key power line that supplies Nairobi with cheaper electricity from the Naivasha geothermal fields pushed reliance on expensive thermal to an eight-month high in June.
The uptake of the diesel –generated electricity rose to 6.7 percent of the generation mix after steady decline over time to an all-time-low of 4.2 percent in April.
This was due to increased generation from geothermal and an increased uptake from hydro sources due to sufficient rainfall since late last year.
Energy Cabinet Secretary Charles Keter told the Business Daily that the vandals damaged one of the two power lines supplying the city centre in April, prompting the use of thermal energy through an alternative line to keep the city powered.
“That is the line that sources power from Suswa where we have the major substation so when it was damaged in April, we had to use the one from Juja –Dandora-Embakasi to supply the city.
Thermal became necessary to avoid overloading the transformers in that line. We also had to reduce geothermal supply since this is one of the key lines that evacuate power from the Olkaria Geothermal zone,” Mr Keter said.
Nairobi is supplied through the 220 kilovolt (Kv) line from the Suswa substation where all generated power is transmitted to first before distribution.
The city also gets its electricity through another line from the Juja substation through the Dandora substation. The move was meant to minimise blackouts in the city.
More uptake of geothermal power was occasioned by the re-routing of two power lines at the Coast region to pave way for the construction of the Sh6.5 billion Kwa Jomvu-Makupa Causeway in Mombasa as the Kibarani area is expanded from two to six lanes.
The move prompted uptake of more thermal to support the remaining 400Kv line from Suswa.
Mr Keter had also told the Senate Standing Committee on energy that the delayed completion of the Olkaria-Lessos-Kisumu transmission line played a role in the increased reliance on the thermal power which affect the cost of power due to the pass through Fuel Cost Charge consumers pay for every unit of power purchased.
The Sh18.2 billion project under construction by the Kenya Electricity Transmission Company (Ketraco) had been stalled for months after wayleave headwinds in Naivasha and Kibos stopped its construction.