27. The electrical energy produced by any device
at sea needs to be delivered to the consumer. There are two stages
of transmission, both of which have their own particular problems:
28. Transmission to the coast is principally a technical
problem, which the companies we heard from were confident of solving,
especially for non-floating devices.
Valuable lessons could be learned from the offshore oil, gas and
wind industries and projects such as the 2,000 MW cross-Channel
electricity interconnector, the new Northern Ireland-Scotland
electricity interconnector and the 20 MW cable across the Pentland
Firth to Orkney, which the islands depend upon for the security
of their electricity supply and which crosses one of the world's
strongest tidal currents.
29. The more difficult problem, and one that individual
companies would find almost impossible to solve alone, is that
of taking the electricity from the shore to the main demand load
centres. Many of the sites around the UK with the highest potential
wave and tidal energy (Western Scotland, the Channel Islands,
the Pentland Firth, Shetland, Orkney, etc.) are distant from the
major load centres (the North-West, Midlands and South-East of
England). The UK's National Grid is, broadly speaking, "tapered"
toward its periphery and was designed to supply electricity from
a small number of large power stations at the 'centre' to the
rest of the country.
It was not, generally, designed to receive energy from multiple
sources in remoter parts of the country and transmit it to the
main load centres (although, there are significant exceptions
such as the Dounreay nuclear fast reactor in the north of Scotland).
The transmission lines are particularly weak in the Western part
of Scotland. This is a problem that Wavegen and Ocean Power Delivery
face, with costs of half a million and a million pounds respectively
merely to pay for the strengthening of the transmission lines
necessary to connect their Islay devices to the Grid.
Mr Thorpe, however, stated that cost of connection to the Grid
were "independently calculated to be much smaller than what
the utilities are asking.".
The difficulties of Grid connections are probably the single
most serious problem facing the successful exploitation of wave
and tidal energy in the UK, and one which no single company can
30. The problem is not merely a technical one but
is directly affected by the structure of charges for Grid connection.
In general, the current structure of charges levied by the National
Grid Company plc in England and Wales does not encourage wave
and tidal energy generators. It favours: (a) 'embedded generation'
(b) generators who establish plants nearer to the main demand
centres, or in areas where there are fewer generators (principally
London, the South-East and the South-West of England); and (c)
larger generators, producing more than 300 MW.
As wave and tidal generators, at this stage of development, are
generally small and located away from the south of England, in
areas which already have their electricity needs met from other
sources, they will find it very difficult to meet the charges
31. In its "Climate Change - the UK Programme"
strategy document, the Government states that it sees its role
as "facilitating and stimulating the emergence of new technologies
... [to] ensure that there are no institutional or structural
barriers to transformation of the energy sector".
The problem of the Grid is clearly a structural barrier to the
integration of wave and tidal energy into the UK's energy system.
As one witness warned, there is a danger that the UK will "end
up with a great generator but no socket to put the plug in.".
Previous Governments ensured the very costly connection to facilities
such as the Dounreay nuclear fast reactor.
The present administration should be prepared to co-ordinate similar
strategic investment for wave and tidal energy. If this is not
done, the commendable targets set for renewable electricity are
likely to remain rhetorical, not real.
32. We welcome the Minister's willingness to "look
at either a role of banging heads together or a role of providing
We recommend that the Government should work with the National
Grid Company, and other utility companies, to organise the strengthening
of transmission lines required, if wave and tidal energy are to
provide a significant amount of energy to the electricity market.
33. One alternative to paying for costly connections
to the Grid is for wave and tidal devices, especially ones far
offshore, to produce hydrogen by electrolysis.
This could be stored at sea and then periodically collected by
ship. At least one company, Seapower Ltd., is considering this.
A useful comparison would be in the smaller, more distant oilfields,
where it is uneconomical to lay a pipeline. Here the extracted
oil is pumped into tanks on the seabed, with a pipe running up
to a buoy floating on the surface. The tanks are emptied on a
regular basis by a ship, which anchors securely and hooks up to
the pipe. There will be an increasing demand for hydrogen worldwide
if, as is expected, hydrogen-fuelled cars become more widespread.
The 2001 Budget, for example, included a "package of measures
... to encourage environmentally friendly fuels and to assist
the move towards a hydrogen-based economy.".