Energy Cabinet Secretary Davis Chirchir has warned of another nationwide blackout if appropriate investment is not channeled towards bolstering power supply across the nation.

According to Chirchir, power supply lines in the country are overloaded, which continues to exacerbate the transmission of electricity to Kenyan homes.

Speaking on Monday, Chirchir intimated that there was a transmission constraint on Sunday at the Kisumu-Muhoroni power line which led to the nationwide power outage.

The CS said that there was an overload at the power line which "felt threatened and it tripped" and "cascaded down to the rest of the country".

"...There was sudden demand and the line is dimensioned to carry 80Mw. When the line went down it was carrying 120Mw and suddenly there was a demand for an additional 20Mw on that line," he said.

In what he called a system constraint, the power trip at the affected line led to a sudden increase in power flow on the Juja-Lesos-Muhoroni link leading to an overload at the Olkaria transformer.

"The power restorations started immediately and by 1 am 60% of affected households had their power restored," he said.

Admitting that the government is grappling with power supply challenges, Chirchir stated that a plethora of mitigations have been proposed to help tame the perennial power outages in the nation.

He said that the government plans to build an alternative line to support supply to Western Kenya from Olkaria-Narok-Bomet-Awendo to support power transmission.

Through funding from South Korea and Africa Development Bank, Chirchir said that the project construction is still at a tender stage which is expected to be completed in about 20 months.

Other areas where there are plans to improve supply stations are Lessos, Kimuka near Kikuyu, and Malaa (set to serve the Nairobi noth line).

He added that the government will fast-track the implementation of battery energy storage systems that will help provide voltage stability.

Chirchir added that there is also an option of forging Private-Public Partnerships as some of the networks will be built by private capital.

"We are now bringing in the PPP to build some of the networks. It will relieve KETRACO from looking for funding from government and having the challenges we have had," he said.

Meanwhile, plans to shed power loads from constrained power lines are underway to mitigate the power blackouts as the long haul process is underway.

"We know where the problem is and we are addressing those challenges. It's bound to happen again but we will look at serious maintenance. The least of it is lack of investment in the network for a long time."

Sunday's outage was the third after the first which occurred on August 25, while the second was on November 11.

During the outage on November 11, it took over 12 hours to restore power in most parts of the country.

In August, after Kenya Power issued a brief statement announcing a "system disturbance leading to loss of bulk power supply," Murkomen apologised after passengers were stranded at JKIA.