Grande Côte, Senegal

The mining camp also has workers’ accommodation, medical facilities and a wastewater treatment plant, all in a location far away from any larger settlements and unconnected to the national grid. A reliable, clean, on-site source of energy, operable in island mode, is essential. 

Grande Côte Operations soon turned to Wärtsilä for their energy solution. One of the joint venture operation’s, Australian based Mineral Deposits Ltd, had already procured a power plant from Wärtsilä for their Sabodala gold mine in Senegal.

One key issue at Grande Côte concerned the need to keep different fuel options open. The mining operations have initially been using heavy fuel oil, but will later shift to cheaper and cleaner natural gas when piped supplies become available. Wärtsilä’s multi-fuel 34DF engines make this possible.

The power plant needs to operate in island mode to provide a flexible baseload for the newly developed mining operations. Since the demand for power will be much lower during the periods of the relocation of the power supply of the dredge vessel, Wärtsilä came up with a special engine configuration for the power plant with four larger Wärtsilä 20V34DF engines, and one smaller Wärtsilä 9L34DF that can efficiently meet lower weekend demand up to 2.2 MW. When mining operations are under way three of the four larger generating sets will typically provide up to 28 MW of power at any time.

Conditions in the sand dunes of the Senegalese coast are hot and dry, with plenty of dust about. This was a key factor affecting the choice of air intake filters for the engines. Water is a precious resource here, so an air cooling system was chosen for the power plant’s radiators.  

Health and safety issues have been given the utmost priority at Grande Côte right from the start of the project. Wärtsilä has organised wide-ranging practical training on safety issues at the power plant, getting all contractors involved as well as people from the mining operations. The plant’s health and safety record has consequently been excellent. 

The clean technology solutions applied in the new power plant fully meet the tough emission guidelines set for the mining project by the International Finance Corporation. Mining operations are today increasingly looking to minimise their environmental footprints including energy-related impacts. 

The self-sufficient and flexible energy solution supplied by Wärtsilä will form an essential element of the Grande Côte Mineral Sands Project over the next 20 years, enabling the efficient utilisation of Senegal’s valuable natural resources through an international collaborative initiative where the Republic of Senegal is a significant owner and beneficiary.