BARRY JOHNSTON, founder of a small Scottish start-up, thinks he has cracked a
problem that has confounded some of the biggest energy companies in the
world: how to harness the power of the sea to generate electricity without
building huge, expensive structures.
His idea is deceptively simple and has already attracted some high-profile
backers. Fred Olsen, the veteran Norwegian shipping and energy magnate, has,
along with the Total oil company, sunk £6.2m into Johnston’s Orkney
business, Scotrenewables, and in 2007 the firm won a £1.8m grant from the
Scottish Executive.
At its heart is the idea that any energy producer must work with the sea
rather than against it. “I’ve lived on Orkney all my life and I’ve spent my
childhood on boats,” said Johnston, who formed the company in 2002. “I’ve
always been very aware of the force of the sea and watching for the tide’s
turn.”
Like other tidal projects, the technology Scotrenewables is testing is based
on an underwater turbine - imagine a wind turbine placed under water like a
propeller, which is turned by the tidal flow. But while companies such as
SeaGen, which has tidal generators on trial in Strangford Lough in Northern
Ireland, secure these huge turbines to the sea bed with big concrete
pillars, Johnston’s are fixed to a floating vessel anchored by cables to the
sea bed.
Johnston said this technique promises lower construction and running costs.
Scotrenewables’ turbines will not need sea-bed foundations that can only be
built for an hour or two each day between tides. Nor does it need expensive
floating cranes and barges to put the turbines in place. Its turbines will
be built ashore and when afloat can be towed back for servicing, another
potential money saver.
“There are huge capital investment and servicing costs involved in fixing
turbines to the sea bed,” he said. “We know it’s possible to generate power
from the tides but if it costs £5m to build a turbine that is expensive to
maintain and generates revenues of only £200,000, it’s not viable.”
Tidal power could form a key plank of the government’s commitment to produce
20% of all its energy from renewables by 2020. According to Stephen Wyatt,
head of marine energy at the Carbon Trust, which is helping to fast-track
promising new green technologies, Britain is perfectly placed to take
advantage of sea power.
Wyatt said: “We have amazing natural energy resources in our tides and seas.
Renewable energy from the sea could generate 20% of the UK’s electricity and
we have a tremendous skills base in this country to help harness it. Our
great industrial and engineering resources in shipping and energy are
complemented by a strong academic base and spirited entrepreneurs who can
turn the ideas into commercial devices. All the links in the chain are
there, which is why we are so excited by wave and tidal power.”
Despite the potential, Johnston warns against complacency: “A lot of people in
this sector have overpromised. I wouldn’t be surprised if it takes five to
ten years before there is commercially produced energy.”
His own vision is still at prototype stage with scale models being proved in
tanks in the European Marine Energy Centre on Orkney, and has yet to be put
to the test in the tempests of the Pentland Firth, the channel between the
Orkneys and the Scottish mainland. When fully functional, Johnston claims
his system will have an output of 1.2MW – sufficient electricity for 700
homes.
Before that can happen there are still some formidable challenges. One of them
is making a floating turbine that can take a beating during storms.
“There are a lot of problems to overcome. Nobody has ever put structures in
such a harsh tidal environment. People don’t even put oil rigs in these
conditions and you can’t just go to a shop and ask for the computer software
to model them for you. That’s what makes this so challenging,” said
Johnston.
And then there is the question of funding. Tidal power is not a technology for
impatient private investors. Wind power took 30 years to develop and settle
on one technology before it became possible to generate commercially viable
energy. And like offshore wind power, someone must build and pay for the
cabling and infrastruc-ture needed to carry power generated at Britain’s
geographic margins to its urban centres.
“Getting funding has been an extremely inefficient process. We’ve been
operating on a shoestring to get from one stage to another. It takes a year
to get funding from anywhere. Meanwhile, we’ve had to do anything and
everything to keep the company alive. It has been hellish.”
Although the government’s renewable-energy targets and general concern about
climate change should help maintain investor and government interest, much
greater commitment to renewable energy is needed to speed up its
development, said Johnston, who ruefully observes the expensive clean-up of
the decommissioned Dounreay nuclear reactor going on a few miles across the
water from Orkney.
“Imagine the impact if the £150m being spent cleaning up there each year was
spent on developing renewables. I ask myself if the government is really
serious about this and also when my grandchildren grow up what kind of world
will they be living in?”
Tidal race GREEN IDEAS
NEARLY a quarter of the electricity used by businesses might be wasted, says
Energy Management Systems of Rotherham (www.ems-uk.org). It says most small
firms’ equipment is designed for lower voltages than those supplied by the
grid, meaning up to 25% remains unused. EMS’s Powerstar transformer
optimises energy use for actual requirements, saving 10% in costs for every
5% drop in voltage.
Got a great green idea? E-mail it to us at greenideas@sunday-times.co.uk
and share it with the world
Tidal race
Matthew Wall
IT has been three decades since Whitehall first looked into harnessing energy
from the Severn estuary’s tides. At every turn it has been rejected for
financial and environmental reasons. The newfound need to “go green” could
finally push it over the line.
Last month the government breathed fresh life into the idea of building a
“barrage” of up to 10 miles stretching across the waterway that it says
could provide up to 5% of the country’s energy needs.
The plan for a barrage from Cardiff to Weston-super-Mare was one of five
short-listed for consultation. Other ideas include tidal reefs and lagoons
that would produce a fraction of the energy but cost much less and do less
environmental harm.
Campaigners like the Royal Society for the Protection of Birds have railed
against the destruction of vital habitats.
It could create as many as 18,000 construction jobs but some government and
industry bean-counters argue that the £22 billion it could cost would be
better spent elsewhere. The environmentally friendly lagoon and reef ideas,
which would produce as little as a fifth of the energy of the big barrage,
seem to fall short of the government’s stated goal of producing a
“strategically significant” amount of energy from the project.
At a conference that the Institution of Civil Engineers is holding next week
on the issue, Rod Rainey, head engineer at Atkins, the consultancy, will
call on the government to resurrect the most ambitious idea of all, a
barrage from Minehead to Aberthaw that would cost up to £30 billion to build
– £10 billion more than the short-listed Cardiff-Weston project.
“It costs 50% more, but produces 50% more power,” he said. If history is a
guide, the most likely outcome is that in another three decades the Severn’s
tides will still be flowing free and unencumbered.
