POWER
PLANTS

Power Generation

Our engineers have been involved in the full electrical and instrumentation design of four hydro power plants in Africa and multidisciplinary design of two co-generation projects and one 100MW combined cycle gas turbine (CCGT) plant in South Africa.

We completed the design, construction and commissioning of a 17MW clean fuels power project in early 2011 and completed the design of another 27MW clean fuels power project in South Africa.

In 2012 we completed the design and commissioning of the Aggreko International, Ressano Garcia, Mozambique 107MW power plant. For this project we did the full design and commissioning of the 11/275kV substation as well as the 7km 275kV transmission line.

We have an in-depth understanding of the African power market and we can advise our clients substantially on the development of Independent Power Plants (IPP’s) in Africa. Here our expertise extends past the engineering aspects of the projects but include the full feasibility and preferred technology concepts.

Part of the services we provide is for the management and procurement of the generation license, application for grants where available credits and overall management and execution of the pre-feasibility and feasibility studies.

We were responsible for the designs and operations of the 2009 Confederation Soccer Cup as well as the all-important 2010 Soccer World Cup.

During the World Cup we designed and commissioned a total of 75MW’s of power generation between the various events stadia.

IFM 17MW Power Plant after Construction

Eternity / Anglo 5MW ORC – 2015

River flowing out of the turbine

Hydro Power

Hydropower is the term used for the generation of electricity using the potential energy in water due to gravitational forces.

The first power plants ever constructed actually used hydropower and therefore hydropower is nothing new.

There are a number of different turbines on the market that uses water as the feedstock or source of energy. The formula for hydropower potential is straight forward. It is simply the volume of water in cubic metres per second available multiplied by the height (m) available multiplied by the gravitational force of the earth and then making allowance for the efficiency of the turbine and generator combination.

South Africa and the world have a vast number of mines of varying depths. Almost 90% of the mines in the world utilises water underground which is sourced from surface. We are all so used to mines pumping water and sludge out of mines that we have forgotten about the opportunities of recovering the energy from the water that we send underground.

Underground mines are very seldom less than a couple of hundred metres deep. Certain very deep mines are even up to 3 000m deep. If a mine of a depth of 3 000m uses only 100 litres of water per second, then that mine can easily generate 2,3MW of power from this meagre supply of water. One of the obstacles is the fact that with the above method of calculation the water after exiting the turbine is at 0 bar pressure. The mines send the water down to do some work and they normally require the water to be at pressures varying from as little as 5 bar to as high as 20 bar pressure.

This does not mean that you can no longer generate electricity we are able to deliver the water at the required pressure to the mine. 20 bar Pressure is for example equal to 200m of head and 5 bar pressure only equals 50m of head. Thus if we still take our example above, we can by delivering the water at 20 bar pressure still generate 2,2MW of power and at 5 bar almost no change to the 2.3MW of electricity.

How do we do this? This is quite simple. All we do is to install a back pressure turbine that exhausts the water at the required pressure.

For a more realistic mine having a depth of 500m to the working face and requiring 5 bar pressure and having still 100 l/s of water, we can generate 350kW of electricity. This might sound like not a lot in comparison to the amount of power used by a mine, but this at 2014 Eskom tariffs equal a cost of R 2.1m per annum of electricity.

The same principles applies to any source of water flowing over a waterfall or having a gradual drop.

We designed supplied and installed a 315kW turbine on a farm in KZN where the farmer has a 40m waterfall and approximately 1000 l/second to spare. Remember the water is not used it is purely returned to the source at a lower level.