VRA to shut down one turbine

Power generation from the Akosombo Dam is ex­pected to drop from the current 520 megawatts to 390 megawatts due to a drop in water level.

The Finder newspaper is reporting that the Volta River Authority (VRA) plans to shut down one out of the four turbines before the end of this month, which will result in the loss of 130MW.

As of Monday, November 30, 2015, the water level in the dam dropped to 243.96 feet from its peak of 244.80 feet recorded in November this year.

The hydroelectric dam has six turbines with a capacity of 1,020MW at maximum elevation, but it has been operating on four, sometimes three, turbines.

At maximum water elevation, each turbine generates 170MW of power, translating into 1,020MW from the six turbines.

Data seen by The Finder indi­cates that the water level has been dropping by 0.04 feet every day since the water level hit 244.80 feet on November 3, 2015, the highest this year. Sources told this paper that VRA plans to run three turbines throughout next year in order to guarantee 390MW until rains start in Northern Ghana and Burkina Faso in late July to feed into the dam.

According to the sources, it is the hope of VRA that the Karpowership would start feeding power into the national grid be­fore the end of this year to enable VRA shut down one more turbine out of the four currently in oper­ation.

The Akuse plant will also run three turbines next year to gener­ate 100MW because one turbine is under retrofit.

Ideally, the minimum level of water in Akosombo Dam is 240 feet. Each year, VRA requires 12 feet above the 240 feet to run the dam. However, because VRA op­erated the dam at 235 feet in the past, it is likely to run the dam at that level again this year. This means VRA plans to ab­sorb 9 feet of water instead this year.

The sources told The Finder that if for any reason VRA is forced to run more than three tur­bines, it is likely to reach the 235 feet earlier than August.

They explained that once the water level reaches 235 feet, VRA would be forced to operate only two turbines to generate 260MW.

According to them, once the water level in the Akosombo Dam hits 235 feet, Akuse may have to shut down one more turbine and operate only two turbines.

Water level in the Akosombo Dam dropped to 237.09 feet on August 15, 2015, before the rains started for it to rise to 244.80 feet.

Facts about Akosombo Dam

Maximum operating level - 84.73m (278ft)

Minimum operating level - 73.15m (240ft)

Maximum water level ever recorded - 84.25m (276.41ft) on November 2, 1974

Minimum water level ever recorded - 71.86m (235.76ft) on June 12, 1984

Maximum annual inflow ever recorded - 3000m3/s in 1963

Lowest annual inflow ever recorded - 288m3/s in 1983