Lancaster University
Renewable Energy Group
THE WYRE ESTUARY:
Tidal Stream, Reefs, Fence &
Lagoon Technology Options
Students: Oliver Booth
Paul Edwards
Gareth McMann
Leila Tavendale
Supervisor: Dr George A Aggidis.
February 4th, 2011.
Lancaster University
Renewable Energy Group
OVERVIEW
• Introduction
• Aims and Objectives
• Tidal Stream
• Tidal Reefs
• Tidal Fences
• Tidal Lagoons
• Conclusions
• Next Steps
Lancaster University
Renewable Energy Group
INTRODUCTION
• Alternatives to a tidal barrage
– Potentially cheaper
– More environmentally friendly
– Less opposition from public
• Conceptual technology
– Mostly theoretical ideas
– Not commercially available yet
Lancaster University
Renewable Energy Group
AIMS AND OBJECTIVES
• Examine feasibility of using alternative
technologies
• Estimate power outputs and costing
• Identify the environmental and societal impacts
• Determine optimum site location
Lancaster University
Renewable Energy Group
TIDAL STREAM
Tidal stream energy is the kinetic energy contained
within the currents of water generated by the ebb and
flow of the tides.
The technology used to extract this energy can be
divided into four main types.
•Horizontal axis turbine
•Vertical axis turbine
•Reciprocating Devices
•Venturi effect turbine
TIDAL STREAM
Lancaster University
Renewable Energy Group
The lowest cut in speed for any tidal stream turbine
currently been developed is 0.7ms-1 and have working
depths of 25+m.
There are no tidal stream readings for the Wyre
Estuary itself, from the Atlas Pages maps you can see
the closest data set shows the following:
Velocity
ms-1
Tide
Power Density
Velocity
ms-1 kWm-2
Peak Spring 1
0.52
0.25
2
4.12
0.15
3
13.91
Peak Neap
Lancaster University
Renewable Energy Group
TIDAL REEF
• Concept idea: Low-head
power generation (2m).
• Light impounding
structure.
• Using proportions and
Severn Estuary studies, potential output of
630GWha-1.
• Alternative calculations give 77 – 169TWha-1.
Lancaster University
Renewable Energy Group
TIDAL REEF
• Impacts on shipping: reduced shipping means higher
power generation.
• Environmental impacts: one of the greenest impound
technologies available. ‘Environmentally friendly
alternative to a conventional barrage’.
• Societal impacts: less tourism than a barrage, low visual
impact and reduced opportunity for water sports and
leisure activities.
Lancaster University
Renewable Energy Group
TIDAL FENCE
• Permanently blocks off a section of the estuary
• Does not have to block shipping lanes
• Two main technology types:
• Actual fence device
• Tidal stream devices in a fence array
• VerdErg – Spectral Marine
• Blue Energy David Hydro Turbine
Energy Converter
• Vertical axis
• Pressure drop draws water
• Venturi duct
through turbine
Lancaster University
Renewable Energy Group
TIDAL FENCE
• Has a cut in speed of
1ms-1
• The Venturi duct does
not provide enough
acceleration to rotate the
turbine
• Unproven technology
• Rated to be able to work in
all speeds
• Efficiency unknown
• Power in the water at sites:
• North – 8.33MW
• Central/South – 4.16MW
Lancaster University
Renewable Energy Group
TIDAL LAGOON
•Concept using the idea of natural
lagoons
•Water released from lagoon through
turbines once the tide has subsided
•Can be bi-directional – water flowing
through turbines as tide rises will also
generate power
•Currently an untested
technology
•Feasibility study carried out at
Swansea Bay
Lancaster University
Renewable Energy Group
TIDAL LAGOON
• Southern location best suited
• Maximum output 4.275MW
• Over 50 year lifetime –
1,816,500,000kWh
• Price: 1.6pence/kWh
Lancaster University
Renewable Energy Group
CONCLUSIONS
• Tidal Stream: still not commercially available, the technology
would have to be taken to the resource, reduction in tourism
as there is no visual site in estuary.
• Tidal Reef: unproven technology, unknown costs and
variable power output. More development time and
prototype testing needed before technology should be
considered as a solution.
• Tidal Fence: unproven technology with unknown costs. Full
scale testing must be complete before real estimates of
power and costs can calculated.
• Tidal Lagoon: feasible, may not be necessarily what is
wanted by the people of Fleetwood & surrounding area.
Lancaster University
Renewable Energy Group
FURTHER WORK
• Tidal Stream: selection of a site, power
generation estimations, installation cost
estimations.
• Tidal Reef: power generation estimates need
more work to give a realistic idea.
• Tidal Fence: a different selection of site would
be more worthwhile for this technology.
• Tidal Lagoon: consider lagoon pumping, and the
possibility of locating a lagoon in Morecambe
Bay.
Lancaster University
Renewable Energy Group
THE WYRE ESTUARY:
Tidal Stream, Reefs, Fence &
Lagoon Technology Options
Thank You
Any Questions?
Students: Oliver Booth
Paul Edwards
Gareth McMann
Student:
Name
Leila Tavendale
Supervisor:
Dr George
A Aggidis
Supervisor:
Dr George
A Aggidis.