National power outage: Costs and options

Monday August 6 2018

UETCL technicians at one of the po

UETCL technicians at one of the power stations on the Masaka- Mbarara Road. Last Saturday there was a black out in Kampala and neigbouring districts as a result of a transformer explosion. PHOTO BY SHABIBAH NAKIRIGYA 

By Nelson Wesonga

Kampala- A power blackout enveloped Uganda on Saturday evening, leaving homeowners worried about the fresh groceries in their refrigerators while factory owners turned on diesel generators to light up their plants and run machines.

Following the incident, some electricity users such as Saddam Mulindwa, using @saddtz handle, took to social networking sites to vent that “yoghurt gets spoilt” when power is off.

Relatedly, in response to the notice by Umeme about the outage, @aliza_pearl posted on Twitter, “We have had no power in Kira [in Wakiso District] all day…What are we to do with the supplies we stocked for the week?”
Umeme had earlier posted on Twitter that the Uganda Electricity Transmission Company Limited (UETCL), its supplier, had alerted it of the outage.
“UETCL, UEGCL [Uganda Electricity Generation Company Limited] and Eskom engineers are working around the clock to restore supply,” Umeme posted.
Contacted on Sunday, Eskom Uganda Limited, the South African company managing/operating Uganda’s 380-megawatt Kiira and Nalubaale hydropower complex, referred this reporter to UETCL.

“The most appropriate person to speak to is UETCL, the system operator,” Ms Thozama Gangi, Eskom (U) Ltd’s managing director, said.

The UETCL’s deputy chief executive officer, Mr Valentine Katabira, said the outage resulted from an explosion at the Owen Falls Dam.

“One of the equipment at Owen Falls connecting Nalubaale to Bujagali exploded,” Mr Katabira, an engineer, said in reference to the Daily Monitor’s question.


Asked what caused the explosion, Mr Katabira said, “That is subject of an investigation.”

According to a article titled ‘What Makes Transformers Explode?’ such explosions could happen when there is too much electricity.

“When flooded with too much electricity, the sudden surge can cause a transformer explosion,” read an excerpt of the October 2012 article.
“As transformers detect an energy spike, they are programmed to turn off, but it can take up to 60 milliseconds for the shutdown.

“However fast those milliseconds may seem, they still may be too slow to stop the electrical overload.”

The article said ‘a chamber full of several gallons of mineral oil keeps the circuits cool, but given too much electricity, the circuits fry and melt, failing in a shower of sparks and setting the mineral oil aflame’.
According to June 27 paper that Mr Katabira presented during an Electricity Regulatory Authority organised executive forum on Uganda’s electricity supply industry, Uganda’s installed power generation capacity is 930.54MW.

Firm generation is at 640MW while domestic peak demand is 568MW and the annual mean growth in power demand is 5.3 per cent.

Supply though is increasing exponentially: in the last quarter of this calendar year, the 183MW Isimba hydropower plant is expected feed the national grid.

The 600MW Karuma hydropower plant will be commissioned next year.

These two will increase the installed generation capacity from 930.54MW to 1, 713MW.

To sap up the power, the government is encouraging investors to build factories in Uganda.

To that end, it has reduced the retail electricity tariff for extra-large industries users. Still, Uganda’s tariff for that category of users is higher than Ethiopia’s, meaning the government will have to do more than hope that if you build many power generation plants, industrialists will come in droves to Uganda.

It also plans to ramp up connections, using donor-funds, by subsidising or connecting ‘for free’ households that are near the grid but cannot afford the connection fees.

Regarding outages, Mr Katabira suggested that to nip them in the bud, there should be routine maintenance.

Daily Monitor reported in July that China Electric Power Equipment and Technology Company, a Chinese firm, has approached Uganda with $3b (Shs11.6 trillion) offer to modernise Uganda’s electricity transmission and distribution networks, functions currently undertaken by UETCL and Umeme Uganda Ltd.

The company said it would invest in a Smart Grid, which, according to the International Energy Agency, is an electricity network that uses digital technology to monitor and manage the transportation of electricity from all generation sources to meet the varying electricity demands of the end-users.

During an off the record communication with this reporter on Saturday, an official in the Energy ministry said “developed grids have several feed-in grids and intelligent networks that even if there were an outage, it wouldn’t be noticed by consumers”.