Memorandum submitted by the Environment
1.1 The predictability and reliability of
offshore tidal power offers the UK an important source of clean,
renewable electricity that can suitably fit into the New Electricity
1.2 Pre-feasibility studies confirm that
offshore tidal power will be become economic through its inclusion
in the Renewables Obligation and eligibility for Renewable Obligation
Certificates. Funding does not appear to be a problem.
1.3 The Environment Trust sees the possibility
of synergistic uses of the offshore tidal power technology to
advance other renewable energy technologies, such as wave and
offshore wind power, in the UK.
1.4 Presently, there are no funding opportunities
from UK Government for tidal power. The Environment Trust would
like to see the inclusion of all renewable energy technologies
in the R&D and commercial support mechanisms developed by
Government, facilitating UK expertise in the field.
1.5 As offshore tidal power impoundment
structures will be located in low-lying waters, the impact on
shipping will be negligible.
1.6 The Environment Trust considers that
offshore tidal power will contribute to the local environment
over time. The development of offshore tidal power will have visual,
sediment transport and marine life impacts, but The Environment
Trust believe the positive benefits of offshore tidal power will
outweigh such negative impacts.
2.1 The Environment Trust is a London-based
development trust, which was established in 1979 to promote activities
to improve the environment. The Trust has been involved in over
2000 projects ranging from the development of 200 "Green
Homes" to the £25 million regeneration of Mile End Park
in east London.
2.2 The Environment Trust has also promoted
the development of renewable energy and, inter alia, has been
involved in a number of wind farm projects in the UK. Recently,
the Trust has diversified into tidal energy and has entered into
a partnership with Tidal Electric Ltd to develop a 30MW offshore
tidal power plant in Swansea Bay.
2.3 In view of this involvement in the tidal
power industry, the Trust is responding to the Call for Evidence.
3.1 From its work in Swansea Bay, The Environment
Trust has established that offshore tidal power technology is
a commercially viable form of renewable energy, given the Government's
commitment to a Renewable Obligation Certificate of 3p/kWh.
3.2 The basic technology has been used for
many years in tidal barrages. For example, the La Rance tidal
barrage has operated on every tide since it first started generating
3.3 Offshore tidal power is merely an adaptation
of the barrage technology, building a circular impoundment structure
in shallow offshore waters. Underwater low-head hydroelectric
turbines are used to generate electricity on both the ebb and
3.4 The Trust is convinced that by using
this technology in an offshore installation, the environmental
concerns about tidal barrages can be resolved, whilst allowing
synergistic uses of the impoundment structure for commercial activities.
4.1 A pre-feasibility study has been carried
out for the Swansea Bay project based on the capital cost estimates
of the construction of the impoundment structure and the cost
4.2 Because of the predictability of the
tides, the output of the installation can be estimated preceding
development and, on the assumption that the proposed Renewables
Obligation Certificate is available to offshore tidal power, the
project demonstrates a commercial return.
4.3 Discussions with potential investors
are at an advanced stage for the Swansea Bay project. From the
interest to date, it seems probable that sufficient equity will
be in place to enable the project to proceed within three months.
4.4 Apart from the Renewables Obligation
Certificate, it is not envisaged that any public subsidy will
be needed for the Swansea Bay project.
4.5 The predictability, reliability and
flexibility of offshore tidal power suitably fits in with the
New Electricity Trading Arrangements, recently designed to improve
the overall efficiency of the UK electricity supply market.
4.6 Offshore tidal power is potentially
one of only a few renewable energy technologies capable of offering
flexible services into the Balancing Mechanism of NETA. As the
source of energy is free the technology is not susceptible to
fuel price fluctuations, increasing the long-term flexibility
of the technology.
5. CURRENT PROJECTS
5.1 Present projects
5.1.1 The Environment Trust is presently
involved in one project in Swansea Bay to develop a 30MW offshore
tidal power project. The project has received widespread support
both locally and nationally.
5.2 Project failure
5.2.1 The commercial, technical and environmental
aspects of the technology have been examined in the pre-feasibility
study for the project.
5.2.2 Further, detailed studies will be
carried out before the project proceeds to ensure that the project
will not fail.
6.1.1 Offshore and tidal stream technologies
offer the UK an opportunity to explore alternatives to the original
tidal barrage concept.
6.1.2 The Environment Trust is interested
in both forms of the tidal energy but currently only focuses on
offshore tidal power.
6.1.3 The possibility that offshore tidal
power could be combined with wind, wave and even biomass has been
explored in a preliminary way, with positive results. However,
in the short-term, the Trust intends to pursue the development
of offshore tidal exclusively.
6.2 Greater Priority
6.2.1 In the longer-term, The Environment
Trust intends to promote both tidal and wave energy.
6.2.2 Given the unique, free, power source
available in the UK, the future potential of offshore tidal power
appears to be considerable. The predictability of the tides and
their exclusion from fuel-price fluctuations makes the technology
one of the most reliable, predictable and flexible sources of
energy in the UK.
7. RESEARCH AND
7.1 Present research
7.1.1 To date, research into offshore tidal
energy has been carried out comprehensively by Tidal Electric
7.2 Available funding
7.2.1 Presently there is no financial support
for Research and Development for tidal power from the UK Government.
The recent calls for Research and Development projects for new
and renewable technologies excluded tidal power, whilst including
technologies such as solar, wave, small-scale hydro, wind, fuel
cells and biofuels.
7.2.2 The programme will be given £14
million during 2000-01 and £18 million for 2001-02. Tidal
power is excluded from this programme whilst wave energy is included.
Given the potential of tidal power, it might be appropriate to
reconsider the allocation of funding to include all renewable
7.3 Co-ordination of national funding
7.3.1 Co-ordination of national funding
is not a serious enough issue for The Environment Trust because
of the exclusion of tidal power to date. In the interest of developing
the UK renewables industry, synergy between UK and international
renewable programmes would appear a logical approach for the UK
Government to take.
8.1 Marine Life
8.1.1 It seems clear that offshore tidal
power will contribute to the local environment over time. The
impoundment structure is likely to have an impact in its locality
during the construction phase.
8.1.2 However, once the marine environment
has adapted to the changing hydrodynamics, the structure will
provide a base for marine life to colonise; effectively creating
8.1.3 Entrapment in the turbines housed
in the seaward side of the structure will be alleviated through
adequate screening and sounding. The impact will also only be
during the movement of water from the sea into the impoundment
structure (flood generation), as when the reverse occurs (ebb
generation) it is envisaged the currents will be of significant
magnitude to deter the entrapment of marine life.
8.1.4 The major impact will be the visual
impact of offshore tidal power, which can be alleviated through
landscaping. Once the structure has been colonised, the visual
impact of the impoundment structure will be minimised.
8.1.5 Impact on sediment movements can be
modelled and understood, allowing projects to assess where impacts
will be at their minimum and hence focus identifiable locations.
8.2.1 The impact on shipping is likely to
be negligible, especially as the structure is easily navigable
and will be marked clearly through adequate lights and buoys.
The impoundment structure's most favourable location is on a relatively
flat seabed and such a location minimises the impact on commercial
shipping activities, which require deeper water.
8.2.2 Increased tidal currents can also
be utilised to increase scour in shipping lanes [if configuration
permits], effectively increasing the viability of ports by reducing
the need to dredge shipping channels on a regular basis.
8.2.3 Recreational shipping activities are
likely to be enhanced, as the impoundment structure will create
calm water on the shoreline side for an impoundment structure.
This can effectively create a harbour area for small craft, thus
increasing the number of locations along the coast to house recreational
9.1 R&D Abroad
9.1.1 To date, Research and Development
into offshore tidal power technology has been conducted by Tidal
Electric Ltd, in the State of Alaska, USA. The detailed study
assessed the feasibility of a 6.3MW tidal power plant to meet
the needs of the City of Cordova.
9.1.2 The study proved the technical feasibility
of the project, although political constraints have meant the
project has been put on hold. Focus has now moved to the UK and
the Severn Estuary/Bristol Channel, which has the second largest
tidal range in the world.
9.2 Current projects
9.2.1 Three projects are presently underway
in Wales to develop offshore tidal power, with The Environment
Trust involved in the Swansea Bay project.
12 February 2001