Electricity generated through the manipulation of water has a long and slightly chequered past. The Hoover Dam is considered an engineering marvel, generating 2,080 megawatt hours of energy and has been a tourist attraction for decades. To put this into perspective, the Hinkley Point C nuclear power station currently under construction by EDF will generate 3,260 megawatt hours of energy so not bad for something constructed eighty years ago.
The other end of the spectrum is the ill-fated Osprey 1, built by Applied Research and Technology Ltd, which was destroyed during a storm shortly after launch in the North Sea in 1995. It was the world’s first commercial wave powered electricity generator and was hailed as a major leap forward in renewable energy. Sadly the elements had other ideas and the media labelled it a failure.
Twenty years later and the UK is once again looking at ways in which it can increase water’s share of the energy mix to help power the nation’s 26.4 million homes.
With coal firing plants being shut down by the end of the decade and Hinkley Point C years away from completion, new ways of generating reliable clean energy is needed now more than ever.
Innovations in hydro-electric turbines coupled with a long standing criticism of wind power could breathe new life into what is essentially old technology.
At present, wind turbines generate power whether it’s needed or not, they have no on demand capacity. By the same token, they generate energy at night when demand is low and thus goes wasted. The solution is using this low demand energy to pump water into hydro-electric reservoirs for energy generation during high demand times.
Impressively using renewable energy to power a renewable energy source is only part of the new wave of science driving the industry. Improvements in turbine technology gives hydro-electric dams the capacity to scale up or scale down electricity production based on demand.
Although other countries have been quick to adopt these turbines, the UK’s own have been largely unchanged for the last forty years.
Were these new turbines to replace the six single speed turbines at the Dinorwig dam in Snowdonia, it could increase energy output, at peak times, by 20%. Similarly, at low demands periods, the turbines could be reverse to pump water back up at significantly less cost than running a separate pumping station.
This lost cost improvement to the countries hydro-electric dams – coupled with expansion of key facilities such as Scotland’s Cruachan facility – could see hundreds, if not thousands, or megawatt hours of energy introduced into the national grid.
A Tidal Wave of Innovation
Tidal energy production is as controversial as it gets within the renewable energy sector. The technology is expensive to produce, difficult to maintain and entirely at the mercy of the elements. The Osprey 1 remaining the perfect example of how wrong it can go.
However new schemes are set to tackle the immutable forces of nature by avoiding the very worst she has to offer…
The well documented Swansea Bay project could potentially generate 320 megawatt hours of energy, powering 155,000 homes. The project has come under fire in recent months as experts have thrown doubt over the effectiveness of the generators in the design of the bay.
Similarly the UK’s departure from the EU could cause the entire project to be moth balled amidst the political uncertainty and power health of the sterling.
The major breakthrough, devised by the University Of Oxford Department Of Engineering Science, utilises ‘tidal fences’ to generate energy.
Rather than the convention turbine/propeller designs of traditional generators, tidal fences use ‘transverse horizontal axis water turbines’ which turn with the ebb and flow of currents which means they’re continually generating electricity.
What makes this technology even more impressive is that it actually works better in shallower, slow moving currents rather than the turbulent open sea – waters the UK has in abundance such as tidal estuaries.
Tidal generators are traditionally expensive to install and maintain due to the often violent nature of the waters surrounding the UK so these new THAWT generators have the potential to negate that all together whilst generating on demand energy.
A single 120m long, 10m wide section of tidal fencing could produce between 4.4 and 5.2 megawatt hours of energy. This doesn’t seem all that impressive however a 1km long fence across the Bristol Channel could produce 30 megawatt hours of energy. Were this to be replicated at sites across the UK it could represent a marked increase in clean energy.
The initial cost for 1km of tidal fencing will cost somewhere in the region of £143 million. This may seem expensive, but consider the fact that tidal fencing needs little to no up keep, or expensive fuel or equally costly disposal and decontamination.
If the £24.5 billion invested into Hinkley Point C was invested on tidal fencing it would generate 942 megawatt hours of energy, so less than a third. However, the scalability far outstrips nuclear power and, most significantly, this is just the first wave. As with breakthroughs in commercial electric cars, each iteration of the tidal fence will see a marked improvement in performance.
Could this be the beginning of the renewable revolution promised to us by Applied Research and Technology all those years ago? We’re not sure but we shall be watching with very keen interest.
ALLEN & YORK’s Energy Generation team would like to hear from you. Contact us today if you’re looking for a new role or have a requirement we can support you with; 01202 888 986