Irish Company, Limerick Wave Ltd, Seeks Wave Energy Developer to Trial Their AONTREO Power Take-Off System


Irish Company, Limerick Wave Ltd, Seeks Wave Energy Developer to Trial Their AONTREO Power Take-Off System

Aontreo Logo

Limerick Wave Ltd is a wave energy research company which focuses on the development of Power Take Off (PTO) systems. The company was set up 10 years ago by Patrick Kelly, who has over forty years’ experience in tool design working at the University of Limerick. Patrick was later joined by Dr. Patrick Walsh BEng, PhD, CEng, who is a lecturer in the Mechanical and Automobile Department at Limerick Institute of Technology (LIT).

Limerick Wave’s mission is to turn the mechanical power of the waves (tides) into electrical power for general consumption. Limerick Wave Ltd. has developed an innovative Power Take Off (PTO) technology called Aontreo. The use of the PTO technology in this area is novel in that, its rotation is uni-directional, despite the bi-directional natural oscillation of the flotation device. •Patent Application No. 10723800.8 •Patent Grant No. 2425123

The Aontreo PTO is the result of ten years of PTO development, the first PTO design was tested by the Hydraulics and Maritime Research Centre (HMRC) at University College Cork in 2010. The proof of concept gave them the motivation to progress the PTO research work. The challenge for PTOs used by any wave energy converter (WEC) is to transform the high torque low velocity mechanical power of the waves into rotational power to turn an electrical generator. That is, the Aontreo PTO produces electricity as the sea waves move up and down.

The Aontreo PTO is a Mechanical Motion Rectifier (MMR) that seamlessly turns the bi-directional natural oscillation of a WEC flotation device into uni-directional rotation to turn an electrical generator.

What is unique and novel about the Aontreo PTO?

  1. The Aontreo is a mechanical motion rectifier (MMR), that is, able to turn two-way motion into one-way motion, which then rotates a generator in one direction to produce electricity. 
  2. The Aontreo PTO has designed out the biggest challenge of wave energy conversion (WEC) PTOs, that is, there is no “End Stop” in the Aontreo PTO.
  3. The Aontreo PTO is not rigidly fixed to the WEC, that is, if the WEC becomes compromised the Aontreo PTO is not compromised.
  4. The output from the Aontreo PTO can move under its own inertia, so if the input stops, the output keeps moving.
  5. The Aontreo PTO will work with input movement of +/- 10 degrees.
  6. The Aontreo PTO operates with a turning pair through “one degree of freedom”.
  7. Mechanical input to the Aontreo PTO can change input direction instantly under conditions of “low speed/high torque” and “high speed/low torque”.
  8. The Aontreo PTO is scalable in the same way as a solid drive shaft is scalable.

Limerick Wave’s target audience is WEC developers whose technology uses relative (two way) motion. Limerick Wave want to collaborate with WEC developers to use the Aontreo PTO technology with their WEC technology. Limerick Wave want to work with the WEC developers and when the Aontreo PTO technology is proven Limerick Wave will seek to share in the financial return of having a working WEC and PTO.

The Sustainable Energy Authority (SEAI) has provided much needed finance via prototype grants over the past ten years for the Limerick Wave PTO development.

The Marine Institute and SmartBay Ireland facilitated the testing of the Sea-Power WEC device at the SmartBay Marine and Renewable Energy Test site in 2016/2017, this has provided Limerick Wave with invaluable data in the design of the Aontreo PTO.

Please check out Limerick Wave Ltd’s Youtube video for more information or contact them directly below.


Contact Details:

Dr. Patrick Walsh BEng, PhD, CEng Limerick Wave CEO.


Phone: +353 87 7414550


Limerick Wave Email: