Technology updates

Wind Power in the UK Update (2000)

Tidal Current Power update (2001)

The UK windfarm programme started up in earnest from 1990 onwards, as a result of the Non Fossil Fuel Obligation which required Regional Electricity Companies to buy in set amounts of power from renewable sources - the extra cost of which could be passed on to consumers.

Initially the programme went quite well, although there were some local objections and a single issue pressure group 'Country Guardian' emerged to resist wind developments. Occasionally the opposition had been quite strong, with the main concern being visual intrusion although some of the early windfarms were also challenged on the grounds of noise. However, subsequently, from 1997 onwards, as the programme continued to expand, the level of opposition increased, with Country Guardian playing an increasing role.

Given that the Government sees wind power as playing a key role in achieving its target of a 10% contribution from renewables by 2010, the slow down in the expansion of on land wind deployment represents a significant problem. As the BBC's Countryfile TV programme put it, 'across the country' the wind industry was 'losing the war' adding that 'the majority of its applications are being turned down. Unless a truce is called wind power may not have a future at all' (Rachel Morgan, Country File, 13th October 1996).

Reflecting the mood of crisis, National Wind Power's Peter Musgrove argued that if the planning inquiry inspectors decision not to give planning permission to NWP's 15 machine project at High Moor in County Durham was not legally challenged 'then we and others might as well quit developing windfarms in the UK'. (Windpower Monthly Dec 1998)

So far the problems besetting windfarms in the UK seem to be a uniquely British phenomena. Whereas there have been some objections elsewhere, nowhere have they almost halted the programme, and around the world wind power is moving ahead rapidly: there is around 24,000
Megawatts of capacity installed so far, 10,000 MW in Germany alone, compared with only around 500 MW in the UK. It will be interesting to see if the UK , which has just about the best wind regime of all countries, will remain the odd one out.

So said Dr Peter Musgrove from National Wind Power, as quoted in the Times 9/1/99.

Between Sept 1991 and Dec. 1993, 12 wind farm proposals went before planning inquiries and 9 of these were approved. But since Jan 1994, only 2 of the 18 proposals called in for planning inquiries have won approval. Of course only a proportion of the wind farm proposal are called in for planning inquiries, but even so the trend seems clear. As the Times put it ,' unless urgent action is taken many firms will leave Britain for windpower opportunities overseas', and the UK will find it hard to meet the target of a 10% electricity contribution from renewables by 2010.

Lobbying by groups like Country Guardian, with which Ingham has been involved, has clearly had an effect, with Planning Inspectors beginning to use the same sort of language. Thus, in the case of NWP's proposal for a 15MW wind farm at High Moor in County Durham, the planning inspector blocked the scheme arguing that the individual contribution to energy generation would be 'insignificant and unreliable and that pollution savings would be both correspondingly small and uncertain'. He also claimed that 'in a global context, its contribution may also be readily overwhelmed by increasing pollution originating in other countries'.

The environmental groups however see it rather differently, with national and intrenational groups like Friends of the Earth, Greenpeace, the Royal Society for the Protection of Birds and the World Wildlife Fund for Nature (WWF) all being supportative. However [although] not all environmental groups are in favour of the way the wind programme is being handled. For example, Lilli Matson from the Council for the Protection of Rural England commented (Times 19/1/99) that the problem was the NFFO, and the inherent conflicts in a system where 'subsidies were awarded to the cheapest project with no reference made to their environmental impact'.

This she said

' has lead developers to focus on the very windiest sites, which frequently coincide with our best upland landscapes' . Instead she argued we should 'ensure that environmentally damaging schemes are ruled out from the start and encourage a wider range of renewable technologies to be developed. The result would be less controversy over the location of renewable energy projects and more support for their growth'.

The replacement of the NFFO by the Renewable Obligation in 2002 does not seem to have changed the situation significantly. While national opinion polls continue to show overwhelming support for wind power, some regional environmental protection groups have come out firmly against wind projects, and local opposition to specific projects has remained strong.

Each of these surveys has shown that a substantial majority of the residents who live in an area which contains a wind farm are in favour of wind power, both intellectually by supporting the idea of developing renewable energy sources in theory, but also directly by supporting the construction of wind turbines within their locality.

80% of those surveyed supported their local wind farm. In fact those who live near an operating wind farm were more positive than those who did not. When public attitude projects included two-stage surveys, the first at the time of construction and the second some time after the wind farm had been installed, those interviewed were generally more positive at the time of the second survey. This is thought to be due to the fact that they had been able to see for themselves what an operating wind farm was like. When there were concerns these were generally about noise and/or visual impact.

Again, where the projects included a two-stage survey, concern about these issues was less in the second survey, indicating that actual experience of an operating wind farm appears to reduce a respondent’s concerns about these effects. And the problem is, in any case, diminishing: wind turbines continue to become quieter even with increasing size, a trend enhanced by gear-less turbines.

The UK's wind power expansion programme is grinding to a halt, just at the point when the governments plan is for it to start expanding in order to help the UK to reach its year 2010 target of a 10% contribution from renewables. New projects are increasingly facing opposition, often orchestrated, or at least supported, by groups like Country Guardian. In addition, planning officials and Public Inquiry inspectors often cave in when faced with the difficult task of justifying local intrusions on the basis of global benefits. So what is to be done?

One answer is to give up on trying to push ahead with wind farms on land. Offshore wind certainly has its attractions, but it will take time to get that established on any significant scale and there has also been opposition to some porposed offshore projects. Meanwhile it seems foolish to ignore the UK's huge on-land resource.

Even given more opportunities for public participation and more careful and sensitive public consultation by the developers, opposition may still continue. In which case more radical measures may be necessary. Dave Toke has proposed that only locally owned project be allowed to go ahead. That's certainly a radical proposition. While objections to 'absentee ownership' by large companies has clearly been one of the reasons for local opposition in the UK, not everyone will see relying just on local ownership as a viable strategy.

Local ownership may have worked oversees, but there is no certainty that this form of entrepreneurship would be successful in UK conditions on a significant scale.

The Government tried to support smaller scale community based projects with a 'small wind' tranche in the NFFO, there are still too many obstacles in the way of small projects. As a result, so far there is only one wind co-op in the UK, Baywind in Cumbria, although a number of other schemes have been proposed and there are a handful of smaller schemes around.

Of course, it can be argued that things would be very different if, as Toke proposes, all schemes had to be locally owned. Then all the developers would be focusing on this type of project. Even so, if this approach is to be favoured, then there would have to be significant changes in the support structure, and efforts would have to be made to stimulate support from a wide range of local interests, including, in particular, farming interests.

In principle, there could be other benefits to local ownership, quite apart from converting local opposition into local support. For example, local ownership could stimulate local economic renewal in some rural areas. Wind power projects, and other locally sourced renewables projects, could be embedded in the local power generation network, meeting local needs direct and exporting excess power to the grid. This type of development could underpin local economic regeneration, creating local employment and stimulating new more decentralised patterns of power generation, investment and trade.

It would clearly be attractive to convert a problem, in the form of local opposition, into a solution, in the form of local support. But equally clearly, there is a long way to go before this approach could become widespread. For example, there are a host of organisational, financial and legal implications. 'Local ownership' can cover a multitude of types of organisational arrangements- from formal co-operatives to small conventional business supported by local investors, and also including, presumably, municipal projects. Each has their pro's and con's. What they would have in common is an emphasis on local financial involvement and the delivery of local benefits to compensate for any perceived lack of local amenity.

Whether that would be sufficient to allow the UK on-land wind programme to expand is of course an open question, but as has already been indicated, there is certainly a need for some new initiative. Otherwise, the further development of the UK's large on-land wind resource seems likely to be very limited- as will the potential for rural regeneration from this technology.

The story is continued in Vol. V ' Wind Power in the UK : into the millennium' 2002, £3 from NATTA .

Tidal projects around the world

Rather than trying to capture the energy in the tides via large expensive and environmentally invasive barrages across estuaries, the idea of using tidal currents is being explored around the world. In most cases the emphasis has been on using wind turbine like devices mounted on the sea bed, one of the most developed being the Seaflow device which was tested by IT Power/ Marine Current Turbines Ltd off the coast of N. Devon in 2001.

Support work on environmental impacts and turbine optimisation is being carried out by the Robert Gordon University in Aberdeeen : see
http://www2.rgu.ac.uk/subj/mes/cee/main/Research.htm

However, others have preferred to use vertical axis turbines rather than the conventional horizontal axis propeller design favoured by IT Power. For example, an EU funded study has been made of the potential for tidal current generation in the Straits of Messina, between Sicily and mainland Italy. The proposal was to locate 100 vertical axis turbines on the sea bed, at 100 metres depth.

Even more ambitiously, Dr Alexander Gorlov, Professor of Mechanical Engineering at Northeastern University in Boston, has been developing ideas for tidal current devices for use with ocean currents further out to sea. He is the inventor and patent holder of the Gorlov Helical Turbine - a variant of the Darrieus wind turbine design. Small prototypes have been tested and Gorlov is looking to large scale applications in offshore locations. In particular, he has set up a Gulf Stream project.

Gorlov notes that ‘the Gulf Stream transports approximately 80,000,000 cubic meters of water per second past Miamis front door. This is more than 50 times the total of all the rivers in the world. The surface velocity sometimes exceeds 8.2 feet per second (2.5 meters per second). Thus Nature has concentrated and transfgured part of the incoming solar radiation in the great current systems of the world, such as the American Gulf Stream, the Japanese Kuroshiwo Stream, the African Agulhas-Somali Stream and others. The total power of the kinetic energy of the Gulf Stream near Florida is the equivalent to approximately 65,000 MW’.

Clearly there is a large energy resource and Gorlov has ambitious plans for exploiting it. His aim is to construct a farm of one hundred power modules with 656 plastic triple helix Gorlov turbines mounted in columns in a lattice array. Each turbine would measure 33 in height and 40 in diameter. Sixteen turbines would drive one generator.

This power farm would, according to Gorlov, generate around 136 megawatts in a current flow of 8.2 feet per second or 30 megawatts in 4.9 feet per second. The power would be used to electrolyse sea water to generate hydrogen gas which would then be piped or tanked by ship, to the land.

Dr A Gorlov can be contacted at Northeastern University, Hydro-pneumatic Labs, Dept. of Mechanical Engineering, 321 Snell Engineering Centre, Boston, Massachusetts 02115 USA. Tel: 671 373 3825

Equally ambitious, but further advanced, the Canadian Company Blue Energy has developed a tidal fence concept, in which H-shaped vertical axis turbines are mounted in a modular framework structure- see Fig. Blue Energy is involved in two contracts signed with the Philippines Department of Energy in November 1998. The first is for a demonstration tidal power plant, expected to generate 50MW during peak tidal flow periods and 30 MW on average. The second is a follow up, a 1000MW peak, 600 MW average, capacity plant. The plants will consist of arrays of vertical axis turbines mounted in a permeable causeway, or tidal fence, between two islands, extracting power from tidal current flows.

They are also exploring ideas for an even larger project, a four-kilometre long tidal fence between the islands of Samar and Dalupiri in the San Bernardino Strait (see Figure 13), where tidal currents range up to eight knots - compared to the 4-5 knots that is usually considered to be needed for economically viable tidal current devices). The power plant would have a total estimated generating capacity of 2200MW at peak tidal flow (1100 MW average).

The estimated cost for the Dalupiri passage project is $2.8 billion (US) and Blue Energy say that 'the project could help the Philippines to become a net exporter of electrical power'.

They add that 'the modular nature of the Blue Energy Power System allows for power to be generated in the fourth year of the project, with the installation of the first module in the chain, which gradually increases to full capacity by project completion in year six.

Once begun, this project will be one of the largest renewable energy developments in the world. We expect the project to begin its six year construction phase by the year 2000'. Presumably, this concept would have much less environmental impact than the equivalent scale barrage.

Interestingly Blue Energy also has some even larger concepts in mind. Completing phases 2, 3 and 4 between Luzon and Samar, at a cost of £38billion, would, they say, lead to the availability of around 25,000 MW of generating capacity. This, they say, could provide a key element in a pan-Asian power grid, interlinking the various power systems in the region, and helping to balance local peak demands and local variations in availability of renewable energy inputs around the region. They are also looking at potential sites elsewhere in the world. For details see:

http://www.blueenergy.com

Given that this is a new area of development it may be that, rather than giant projects, it would make sense to focus initially on smaller scale, incrementally developed projects, which can allow for innovative development.

One interesting new idea has been developed by the UK based company, the Engineering Business - the Stingray- a hydoplane with a series of fully submerged parallel wing-like fins harvesting the tidal flows. A protoype was tested off the Shetland Islands in 2002.

Contact: The Engineering Business Ltd, Broombaugh House, Riding Mill, Northumberland, NE44 6EG.

Tel: 01434 682800/01434 682801

email team@engb.com  Web: http://www.engb.com 

Another novel idea the Rochester Venturi (RV) invented by Geoff Rochester at Imperial College, London. The device channels tidal flow in to a funnel to create a small head of water. This is used to drive a relatively small quantity of water around a secondary water circuit, the pressurised water being used to drive a turbine. This secondary flow the developers say ‘ can be maintained for a good fraction of the tidal cycle, so the output is much less sharply peaked than it is from a barrage.’ They add ‘ This means that, for an equivalent electrical energy output, the generating capacity can be less and the duty cycle greater, thereby increasing the economic viability of the project. Tests on a scale model have shown that it should be possible, even on conservative estimate, to convert 20 per cent of the total water power dissipated in the RV into electricity.’

The RV Power Company which has been set up to exploit this concept, are planning to test a small prototype on a riverbank near Grimsby , followed, if funding and a test site can be obtained, by a 2MW version. They claim that the fully developed device should be able to produce electrical power ‘ at between two and ten pence per kWh, with the most viable sites clustering around two pence or three pence per kWh. The greatest uncertainties in our costings come from site-specific issues, marine civil engineering estimates and planning permission’. (evidence to Science and Technology Select Committee hearings on Wave and Tidal Energy, May 2001)

Finally, its is interesting to note that wave energy pioneer Prof. Stephen Salter has also developed an idea for a tidal current device. Dubbed the Solo, the new device is a vertical-axis water turbine mounted on a ring-shaped structure floating on the surface, with its blades reaching into the water below. At full scale the ring would be 50 metre in diameter and the blades would be 20m deep. The complete 600-tonne design could have a generation capacity of more than 12 MW.

Clearly this is still a speculative concept, but it is interesting to compare the idea of using tidal current turbines like this with the tidal barrage concept. As Salter has put 'although the turbine is not as efficient as tidal barrages, it's far more attractive to an accountant's mind. Every time the Government looks at tidal barrages they say if only it was built 20 years ago it would be producing the cheapest electricity on the grid but then they say now isn't the time to build it. You don't get thousands of megawatts from this turbine, but you do get tens and you get it quite quickly. With a tidal barrage you spend billions of pounds before you get any generation at all.’ (Scottish Evening News 04/07/99)

In addition, unlike barrages, tidal stream turbines are likely to have little or no environmental impact. And there would be little visual impact: most of the turbine would be under water. The system would also be virtually silent.

Policy Developments

Be that as it may, the official UK view was, at least until recently, that, like tidal barrages, tidal current technology did not merit much effort for the moment. In the consultation paper produced in 1999 as part of the DTI review of renewables, tidal barrages appear in the DTI's ranking of technological options in the ‘very long term’ category- defined as ‘technologies that are unlikely to be worth pursuing extensively at this time except at the fundamental research level, were this would be perceived as necessary’. However tidal stream devices do not even seem to merit that level of commitment- this option doesn't appear on the ranking chart. The DTI report comments ‘Assessment of inadequately understood technologies will be considered periodically which could lead to reclassification and further support. A technology falling into this group could be tidal stream’.

Not everyone is quite so pessimistic about the prospects for tidal stream technology. For example, although it agreed that tidal stream technology was still relatively underdeveloped, the UK Marine Foresight panel, which was set up to feed ideas about future possibilities into the UK’s Technology Foresight programme, commented that 'since so little work has been completed in this area, the learning curve is still steep and valuable results should be obtained from relatively small further investment in R&D'. ('Energies from the Sea- Towards 2020' A Marine Foresight Panel Report, OST 1999).

While some argue that it wise to proceed cautiously with this new technology, as we have seen, around the world, several large scale tidal stream projects are underway or being considered. It would be tragic if the UK missed out on what could be a significant new area of development and a potentially very large export market.

Interestingly, when the House of Commons Select Committee on Science and Technology looked at wave and tidal current technology it concluded that both merited significantly more attention. In its report published in May 2001, the Committee. Indeed it was quite forceful on this issue arguing that ‘given the UK's abundant natural wave and tidal resource, it is extremely regrettable and surprising that the development of wave and tidal energy technologies has received so little support from the Government’.

The new Labour administration had expanded R&D support for tidal and wave to around £3m, but most of this was for generic development work rather than new devices and very little went to tidal projects. However, as a result of the Select Committee’s admonishment, the situation may change. Indeed, this already seems to be underway: in June 2001, the DTI decided to match the EC’s provisional allocation of 1 m euros for IT Power’s 300MW Seaflow project off the Devon coast, and provided £1m to allow the project to go ahead. Even so, this seems to be seen as very much a prototype ‘demonstration’ exercise. The strategic ‘routemap’ developed by the DTI suggested that tidal current technology would not be deployed on a significant scale until after 2010;

see http://www.dti.gov.uk/renewable/routemap.htm

The UK’s pioneering wave energy progamme, launched in the 1970's, was cut back after adverse (and disputed) economic assessments and a re-assessment in 1982 and abandoned almost entirely following another government review in 1992. However, despite the very visible loss of the Osprey prototype after a storm in 1997, in 1998 a revival of interest occurred in part due to a reassessment of the economics of wave energy. Thus, in May 1998, a special conference, organised by the Office of Science a Technology’s Marine Foresight panel, heard that there had been ‘a considerable improvement in the costs of devices, so that there are now several with costs of 5p/kWh (or less) at 8% discount rate’, and the then energy Minister, John Battle, indicated enthusiasm for wave energy. Subsequently, the DTI's review of renewables, which ran from 1997-2000, in effect reinstated wave energy in bureaucratic terms, shifting from the ‘very long term’ category in its ranking of options, to the ‘long term’ category.

An ETSU report (R122) produced as part of the DTI review, concluded that the theoretical resource was 100-140 TWh p.a. for nearshore/onshore devices and 600-700 TWh p.a. for offshore systems. It suggested that in practice, onshore and nearshore wave devices might supply up to 2.5 TWh p.a., while the practical offshore potential was put at 50 TWh p.a. Overall, ETSU saw wave power making a significant showing by 2025, with the cost-resource curves at 8% discount rate cutting the x-axis at 3p/kWh.

Clearly to achieve this would require the development of new improved devices and subsequently DTI funding was promised for a new wave energy R&D programme. We have yet to hear what though!! All that exists at present, is a commitment to three small wave devices to be supported by the Scottish Renewable Order, although, given that the SRO (like the NFFO) is to be replaced by a Renewable Obligation, new funding arrangement will have to be made for the these projects. One is Wavegens Limpet, an enlarged 500kW version of the 75kW shoreline mounted Oscillating Water Column (OWC) unit already tested on Islay. The new device is now operating and feeding power to the local grid. See http://www.wavegen.co.uk. Another device is Ocean Power Delivery’s Pelamis - a novel snake like device consisting of hydaulically linked segments which twist and turn in the waves, meeting them head on. Scale models have been tank tested, and the prototype is due for sea testing in mid-2001, to be followed by the full SRO version in mid-2002. See www.oceanpd.com. The third, a Swedish design, is a floating TAPCHAN type system, with a reservoir mounted on a pontoon topped up by the waves. The total capacity involved for the three systems is 1.9 MW- small, but a start.

Wave Energy developments elsewhere

Wave energy has also seen something of a renewal elsewhere in the world, with existing technology being exported and new technologies emerging. For example, Portugal has installed an Oscillating Water Column system, rated at 500 kilowatts, on the island of Pico in the Azores. Norway has exported its TAPCHAN reservoir concept and a system is being installed in Java. Interest in the idea has been shown by Chile, India and Sri Lanka.

In terms of new technology, as can be seen, the devices range from, essentially, developments of existing concepts, like the OWC, to radical new ideas, like the Pelamis. The Ocean Wave Energy Convertor, being developed in the USA, seems to have some similarities with the Lilly pad and hosepump concepts. It consists of a series of buoys, with driveshafts connected to pistons, which are raised and lowered as waves pass through a module array. This relative motion between buoys and submerged portions drives transmission and generator assemblies. See http://www.owec.com

In the same way, the ConWEC (Controlled WEC) being developed in Norway also has similarities with the various existing wave piston devices. It consists of an oscillating float type device which drives a piston, which pumps sea water into store, with this then being used to drive a turbine. Tests with scale models with float diameters up to 0.44 metres are to be followed by full scale devices with diameters of 3-8m, which could deliver 10-300kW.

For details see  http://www.caddet-re.org

The Dutch have developed a novel Dutch Archimedes Wave Swing (AWS) . It consists of a series of linked mushroom shaped air chambers which rise and fall in sequence with the wave pattern, and pump air through a turbine to generate power. The AWS is being developed by Teamwork Techniek, a Netherlands based organisation, who claim that it will be competitive with other energy generation technologies. Teamwork expect that its 8MW three chamber design will generate power at a cost of 9 to 15 cents per kWh and note that, globally, there are around 20,000 kilometers where systems like this can, in theory, be installed.

In Australia, A$ 750,000 has been allocated for the development OWC type device which uses a parabolic funnel to focus incoming wave fronts to increase the power. The developers, Energetech, say they have also developed a novel two-way turbine, which, is four times more efficient than the Wells turbines normally used with OWC's. A 300kW version is to be tested at Port Kembla, and overall the Energetech device is estimated to be likely to generate power at around 4p/kWh - and possibly less when fully developed.

Perhaps the most radical of all, is a US design for a wave energy device using a new piezo-electric polymer to generate power. When deformed mechanically (e.g. stretched or bent) piezo electric materials can generate electricity. Ocean Power Technology (OPT) in Princeton, New Jersey, are using a plastic PVC type piezo electric material for an offshore wave power generator that converts ocean wave movement directly into electricity, without the need for any of the moving parts that make up a conventional generator.

There are many other developments underway around the world, including a wave energy device for use as a power source for desalination in Israel (see: http://www.beacon.co.il/ETZ/) and plans by the Norwegian oil company Statoil and also by the UK based oil company British Borneo to use OWC systems to provide power for oil rigs. In addition, Ireland proposed IRL £1m for wave energy under its version of the NFFO, and OSPREY was one contender, although this project has, it seems stalled.

However, to round off this review of developments, mention should perhaps be made of Denmarks ambitious wave energy programme, with had a budget of DKK 20m (£2m) for the first two years (1998-99), to be followed by a further DKK 20m for another two years.

It aims to repeat the very successful Danish wind energy programme in the 1980's by supporting a range of concepts and inventors. So far more than 20 ideas and concepts had emerged and a process of assessment is now underway. Several projects have reached the first stage, leading on the prototype development, including the Waveplane, the Point Absorber system, the Wave Dragon and the Swan.

The Waveplane is a wedge shaped device which funnels incoming waves of varying frequency into a trough in a spiral configuration, creating a vortex which is used to drive a turbine. A 1:5 scale model has been under test in Mariager Fjord in Jutland since May 1999. The Point Absorber is a device with a float on the surface connected to an anchor point on the sea bed. The relative movement between them pumps a hydraulic system to generate power. A 1:19 scale model has been tested and a 20-30kW version may follow.

The Wave Dragon is effectively a floating Tapchan type device- waves flow up a tapered channel and a head of water collects in a reservoir. A 1:50 scale model has been tested at the University of Aalborg. The next step is probably a 1:3 scale version or a full scale version by 2002, this project being part of the EU Wave Energy programme.

Finally, the Swan DK3 is based on the L-shaped 'backward bend duct buoy' concept initially developed in Japan and then China. Following lab test in 1998, an offshore model is planned this year. For more details see CADDET's web page: http://www.caddet-re.org

The European Wave site is a good starting point:

http://www.ucc.ie/ucc/research/hmrc/ewern.htm  

The Danish site:  http://www.waveenrgy.dk is very useful, as is the Norwegian site:

http://www.phys.ntnu.no/glos/grupper/stralbol/bolgegrp-e.html  

The pioneering wave energy group at Edinburgh University has a site at :

http://www.mech.ed.ac.uk/research/wavepower/index.htm

The pioneering UK company Wavegen's site is at http: www.wavegen.co.uk