STAznanost

Slovenian company develops device to generate power from waves

Ljubljana, 17 September - The Slovenian-based company Sigma Energija (Sigma Energy) has developed a device that can convert the energy produced by sea waves into electricity in a sustainable way without carbon emissions.

Sigma Energy successfully deployed a prototype of its 30-kilowatt wave energy converter SigmaWEC off the shore of the Montenegrin city of Bar in July after two and a half years of intensive development.

The system has been patented and manufactured by Mile Dragić, the owner and head engineer of Sigma Energy. The patent features 120 protected innovations that have been validated in more than 40 countries worldwide, he has told the STA.

SigmaWEC is a point absorber type of a wave power plant that transforms wave-induced vertical motion of the circular floating buoy into electricity.

"It is composed of two working bodies. There is a floating body that is moved by the waves, and a transmission system that converts the vertical motion of the floating body into rotation of the generator," Dragić explained.

"The second working body does the useful work while the first body is lifted. This design gives us a light, efficient, inexpensive and reliable structure that has a particularly high degree of efficiency."

In its initial phase SigmaWEC is already more than 40% efficient, which Dragić compared to 30% efficiency of thermal power stations.

The company has also patented a system for anchoring and reducing the forces in anchor ropes.

Dragić says the greatest value of his converter is that it is capable of generating green, carbon-emission free energy and can thus contribute to mitigating climate change, and its disastrous consequences.

Sigma Energy was launched in 2008 in order to develop and deploy the immense energy potential of water, which covers more than 70% of the Earth's surface.

"Wave energy is known to be predictable and heavily per unit of surface, more than wind or solar energy," said Dragić.

"The amount of wave energy near the coast is estimated at 80,000 terawatt hours per year in a single line, and the global annual electricity consumption is currently around 23,000 terawatt hours per year, or several times less than the available wave energy potential."

Considering that 50% of the world's population live within 200 kilometres of the coastline, they could be directly supplied with electricity from sea wave power stations, he added.

The project received an important boost by winning co-funding from Supplement to SME Instrument - Phase 2. The investment was co-financed by Slovenia and the European Regional Development Fund.