last updated 6th October 05
By 4ecotips

Unique Manchester "Bobber" will reap sea's power

There's nothing new about harnessing the sea's perpetual motion to provide electrical power, the concept has been floating around for over 30 years.

In May this year the Ocean Power Delivery company secured the first order for three of its Pelamis Wave Energy Converters to be located 5km off Portugal's northern coast. This is the 80m Euro initial phase of the world's first commercial wave farm and will generate 2.25MW enough to meet the average electricity demand of 1,500 households.

Pelamis is based on a series of semi-submerged tubes which, via a series of hydraulic motors and generators, convert the wave motion into electricity.

However, for the past two years the UK's University of Manchester and the University of Manchester Intellectual Property Limited (UMIP) in partnership with Mowlem plc and Royal Haskoning, has been developing an innovative and patented new wave energy device known as the 'Manchester Bobber'.

The project, which has received Carbon Trust funding, was showcased at the New & Renewable Energy Centre (NaREC) in Blyth, Northumberland, last month (September). The design, development and testing of the device has been carried out at the university led by Professor Peter Stansby and Dr Alan Williamson.

MOVEMENT TRANSMITS ENERGY
The Manchester Bobber's inventive features utilise the rise and fall (or 'bobbing') of the water surface. This movement transmits energy, which is then extracted by the mechanics to drive a generator and produce electricity.

The vision is to have a series of 20-30 Bobbers, which are concrete cylinders, working together on a special platform sitting on the seabed, to generate electricity. One concept currently being explored is the use of decommissioned offshore rigs as platforms for the devices.

Professor Stansby, the university's Professor of Hydrodynamics, says: "Offshore wave energy represents a substantial concentrated 'green' energy source for an island state like the UK.

"Energy from the sea may be extracted in many ways. It is the hydrodynamics of the float employed by the Manchester Bobber that provides the vital connection to generating electricity.

"These days we have a lot of data on what we call 'wave climate'. This tells us the height of waves and what period of waves are actually available through many years. So we know precisely what the wave climate is at a number of suitable locations around the British Isles, and around the world too."

REALISTIC APPROACH
Thousands of Bobber platforms would be needed to meet the UK's entire electricity demand. Professor Stansby suggested it was more realistic to look at providing 10%, 20% or even 30% of the demand.

One of the Bobber's unique features is that vulnerable mechanical and electrical components are housed in a protected environment well above sea level, which makes for ease of accessibility.

Phase One of the project (testing of 1/100th scale working model) was successfully completed in January. Phase Two, which is commencing now, involves a 1/10th scale device that has been constructed and will be tested at NaREC over a two week period. Mowlem plc and Royal Haskoning are also developing and costing conceptual designs for a full scale platform.

Phase Three will involve a full scale prototype being constructed and tested in parallel with detailed costings and engineering design for the optimum full scale concept from Phase 2.

The project team see the Manchester Bobber as a key international development at the forefront of the renewable energy sector. Dr Frank Allison, Assistant Project Manager from University of Manchester Intellectual Property Ltd (UMIP) said: "We are really excited about the potential of this project and can't wait to get the prototype Manchester Bobber constructed and tested. Also it will be an ideal opportunity for people from the industry to come and witness this principal milestone and important achievement."

For more information www.manchesterbobber.com or email frank.allison@umip.com

Animated illustration by kind permission of University of Manchester Intellectual Property Ltd (UMIP). Copyright for the Manchester Bobber flash animation belongs to Royal Haskoning. Royal Haskoning have kindly provided permission to 4ecotips for the display of the Manchester Bobber in this article only. Please contact www.manchesterbobber.com for further information.