Owen falls dam: Powering Uganda for five decades

By Ibrahim Kasita

Age is just a number, goes an old adage. Owen Falls Dam, which houses Uganda's hydropower complex, is a perfect example.

The power station — the biggest and cheapest source of energy driving Uganda's economy - was built between 1950 and 1954.

Records from the energy ministry indicate that the total project cost £22m. Queen Elizabeth II commissioned the plant on Thursday, April 29, 1954.

Even though the plant is 58 years old, the economy still heavily relies on it.

The first two units (1 and 2) were commissioned in 1954. Additional units (3 and 4) were later commissioned bringing the total installed capacity to 60 megawatts (MW). But the electricity supply exceeded the demand for it.

The population at that time was about 5.9 million, but only 11,500 households had access to electricity. The rest of the population used wood and charcoal for fuel.

The electricity — managed and run by the Uganda Electricity Board (UEB) — was sparingly supplied to a few coffee, textile, and corn mills, public premises, hospitals and military installations.

This meant that five kilowatts of electricity were available per household. This is enough power to run a cooker, a fridge, a flat iron, a radio, a TV set and provide lights for a medium sized house at the same time.

Exporting electricity to Kenya

There was also excess power available for export. Therefore, the colonial regime thought it made economic sense if they exported electricity to Kenya.

In 1955, Uganda and Kenya signed an agreement to supply Kenya with 45MW of electricity for 50 years.

However, this was reduced to 30MW to accommodate growing demand in Uganda.

Then in 1957, two more units (5 and 6) were launched at the Owen Falls Dam, raising the installed capacity to 90MW.

Phased commissioning of the units is dictated by growth in demand.

Between 1958 and 1959, Units 7 and 8 were also added, raising the total installed capacity to 120MW

In 1966, Unit 9 was commissioned at the power station, bringing the total installed capacity to 135MW.

Finally, the last unit (Unit10) was commissioned in 1968, completing the rated installed capacity of 150MW.

The population of Uganda had then grown to 9.5 million and 55,400 households were connected to the electricity grid.

Availability of electricity to the household had reduced to 2.7 kilowatts per household.

During the Idi Amin era in 1971, maintenance of the station declined greatly. Between 1971 and 1986, no major developments took place in the power sector.

The adverse economic and political environment then could not even permit smooth operations and maintenance of the existing electricity infrastructure.

There was no foreign currency to import spare parts. Skilled personnel fled the country and a series of wars left the electricity network in shambles.

Renovation starts in 1986
By 1986 when the NRM Government came to power, the Owen Falls Power Station had deteriorated so much, that only four of the 10 generating sets were operational.

The installed capacity of the power station had, therefore, been degraded from the 150MW attained in 1968 to only 60MW.

The second power project was therefore formulated to rehabilitate and restore the capacity of the station and at the same time to uprate it from 150MW to 180MW.

The project was also to address the rehabilitation of the associated transmission and distribution networks delivery of power to load centres and individual homes and factories. The full installed capacity of 180MW was achieved by May 1996.

Demand overtakes supply

By around 1988, demand for power had outweighed its supply. Then load shedding was introduced to ration the available power. Electricity exports were relegated only to off-peak hours.

The third power project was the construction of the Owen Falls Extension Power Station (Kiira), a 200MW hydropower station.

This is situated on the right bank of the Nile River, as one faces downstream.

The main objective of the third power project was to continue and build upon the rehabilitation work undertaken in the second power project to prevent power supply bottlenecks that would otherwise hinder economic development.

The project was to further provide the urgently needed least cost capacity additions to Uganda’s power generation, increase the safety of the Owen Falls Dam and expand the transmission and distribution facilities to satisfy the requirements of all the productive sectors of the economy.

In 1993 work started on the Owen Falls extension project, a second powerhouse located about 1 km from the Nalubaale powerhouse.

A canal was dug to bring water from the Lake Victoria to the new powerhouse. Major construction was completed in 1999, installing two units in 2000.

The extension has space for five hydroelectric turbine generators. By 2003, three turbines had been installed. Each unit at the extension has a capacity of 40MW

Prolonged drought

The hydropower generation at the Nalubaale and Kiira stations has been curtailed due to a prolonged drought which started in 2003, causing low water levels on Lake Victoria.Generation dropped from 270MW in 2004 to 120MW in 2007.

The drop in water levels had a big social and economic impact on the region. The current peak demand for electricity stands at 443MW and the country has a demand growth of about 8% per year.

 This means new power stations need to come on board. Yet the available power supply is 380MW. This has caused a shortage of 143MW

However, down the river from Nalubaale and Kiira, the multi-billion dollar Bujagali hydropower dam is nearing completion.
It is expected that when it starts operating, it will alleviate electricity poverty.

But we shall still remember the mighty Owen Falls Dam, which has driven Uganda’s economy for over five decades, even if it is decommissioned later.