State-run Saudi Electricity Co (SEC) has signed contracts worth 618.5 million riyals ($164.9 million) to build five substations in the capital Riyadh to meet growing demand, the company said on Tuesday.

The company signed a 392 million riyal contract with Saudi Arabia's National Contracting Co for one substation, due to be completed in 29 months, SEC said in a statement.

It signed a 226.5 million riyal contract with Al Toukhi Company for Industry, Trading & Contracting to build four substations in 27 months as part of efforts to meet rising power demand in Riyadh, the statement added.

Demand for power in the top oil exporter is growing at around 7-8 percent per year.

Saudi Electricity, which produces around 40,000 megawatts, plans to spend $80 billion to add 20,000 MW through 2018, plus $20 billion on independent power producer (IPP) projects to add more than 10,000 MW of capacity.

Around $46 billion of the total investment would be spent on power generation, $30 billion on transmission and $20 billion on distribution, a top company official said in October. (Reuters)