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The hockey stick is alive and well
Climate Change: An Urgent Case for Altering our Practices
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Many of the current and future effects of climate change are being reported in our media, and we are all developing a deeper understanding of what is at stake. Most reporting portrays serious but gradual changes in our environment, although there are occasional references to "tipping points leading to catastrophe." Typically, these tipping points or catastrophes are not explained, so they seem academic and somewhat remote.
http://www.greenbiz.com/column/2008/08/18/climate-change-urgent-case-change-practices As the planet heats up, we are learning that a number of significant changes are occurring. From animals perishing by being unable to adapt quickly enough, to melting ice sheets, to forests and oceans becoming uninhabitable for micro- and macro-organisms, we appear to be on the verge of several major tipping points, ecologically speaking. With this first article, I aim to clarify how studying the past can inform the future, particularly in terms of global climate change. If we continue to release greenhouse gases at our current pace, we may see a massive disruption, far worse that those outlined above, which paleontologists are revealing from analysis of past extinctions. One hopes that as more people become aware of this threat, we will shift to emergency measures in the very near term for cutting carbon emissions to zero. The work of paleontologists -- as interesting as it may be -- hardly seems relevant to how we lead our lives. But the recent work of some paleontologists proves just the opposite. The relevance of this knowledge couldn't be more important to our current living patterns and our future. Since the beginning of the Phanerozoic Eon 545 million years ago, there have been five major extinctions and a number of smaller ones. Phanerozoic means "visible life" in Greek. This fossil record, along with other physical traces, allows the paleontologists to recreate past events. About 250 million years ago, the largest extinction by far occurred between the Permian and Triassic Periods, called the Permian Triassic Boundary Extinction, or P-T Extinction. The paleontologists estimate that 95 percent of animal and plant species in the biosphere died off. Scientists have investigated the causes of the different extinctions for some time. For example, the Cretaceous-Tertiary Extinction, which killed the dinosaurs, is now largely believed to have been caused by an asteroid hitting the earth. But what was the cause of the catastrophic P-T Extinction? Scientists have found that at the beginning of the P-T extinction period, a breach in the earth's crust in Siberia allowed a massive outpouring of magma -- called the Siberian Traps -- over hundreds of square kilometers, and with it a huge release of carbon dioxide and methane. While this release significantly warmed the oceans and the atmosphere, some scientists believe that the warmer oceans triggered the release of an additional, much larger quantity of frozen methane hydrates from the continental margins under ocean waters. This led to very different conditions everywhere on the planet and a huge die off of flora and fauna. Methane is a byproduct of the decomposition of biomass. It is estimated that 99 percent of all methane hydrate -- methane frozen in ice crystals -- is at the bottom of the oceans, and one percent is in frozen tundra. Most of the focus in public discussion has been on the release of land-based methane hydrates ("the tundra is melting and out-gassing"). While this source of methane is problematic, the oceans pose a far, far more serious potential release of methane. If the release of methane in the ocean is "slow" enough, then anaerobic bacteria will consume it. If the release is too "fast," then much of the methane goes into the atmosphere, where it is about 20 times more powerful as a greenhouse gas than is carbon dioxide. During the P-T extinction, heat and acid rain killed most of what grew, ran, or flew on land. It took 10 million years in the Triassic Period for the biodiversity to begin its return, and another 10 million years to fully restore it. Scientists have determined that we have been releasing carbon dioxide faster now than at any time in the Phanerozoic Eon. If we continue at this level (or greater) of carbon emissions, it seems more a question of when, not if, we will create conditions where huge quantities of oceanic methane hydrates will be released. Rather than taking thousands of years, they speculate that a methane release could take place over a much shorter period, given the high rate of carbon emissions in which we now indulge. Our civilization is generally unaware of the real possibility of a catastrophic disruption like the P-T Extinction happening in a "human time scale." Awareness of this threat should motivate us to take emergency measures now to cut our carbon emissions to zero in the next few years. In my next column, I will provide guidelines for using a tool known as the Greenhouse Gas Calculator which will enable business owners to calculate their current baseline of carbon emissions and set reduction goals. In the meantime, you can calculate your own carbon footprint and set personal reduction goals by visiting the following websites:
In "Climate Code Red," Spratt and Sutton report a very compelling case as to why we're beyond the phase when we can "think about this." They show that global 2007 emissions exceed the worst case scenarios of climate models and why drastic actions are needed to reduce our CO2 emissions footprint. Christopher (Kit) Ratcliff, FAIA, NCARB, LEED, is the third generation leader of Ratcliff, the century-old, award-winning architectural firm in Emeryville, California. He has pledged the firm's resources toward sustainable practice in concert with the AIA's 2030 Challenge and is committed to bringing the impact of greenhouse gas emissions on climate change to the attention of clients and colleagues. Visit www.ratcliffarch.com to learn more. |
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Green Standards for New Buildings Come Into Effect September 5th
By Ministry of Housing and Social Development
VICTORIA – Every new building in B.C. will meet progressive standards for energy and water efficiency beginning Sept. 5, Housing and Social Development Minister Rich Coleman announced today.
http://www.civicinfo.bc.ca/302n.asp?newsid=2884“The greening of the B.C. Building Code will provide homebuyers with an environmentally sound choice – a home that will have a lower impact on the environment and that will have the added benefit of saving them money on utility fees,” Coleman said. New houses, multi-family residential buildings under five storeys, and small commercial and industrial buildings must meet new insulation requirements. As an alternative to meeting the insulation requirements for housing, builders can demonstrate equivalent energy performance or achieve an EnerGuide Rating System rating of 77. The EnerGuide program uses computer software to evaluate the energy efficiency of the building, and designate a rating number based on the results. Builders can choose to use a combination of different building materials and techniques to achieve an EnerGuide rating of 77. New high-rise residential buildings and larger commercial buildings must meet the American Society of Heating, Refrigeration and Air-Conditioning Engineers 90.1(2004) standard. ASHRAE 90.1 is an internationally recognized standard for energy efficiency. It applies to several components of the building: the building envelope; heating, ventilating and air conditioning systems; water heating; power, lighting; and other equipment. To improve the water efficiency of homes and other buildings, ultra low-flow toilets and other water saving plumbing fixtures will be mandatory. The new green requirements, which apply to all new construction in B.C., were announced in April, giving industry and local governments time to become familiar with the changes. More information is available online at www.housing.gov.bc.ca/building by clicking on the ‘Greening the B.C. Building Code’ button. The Province is exploring additional ways to reduce the impact of buildings on the environment by further improving water conservation, reducing energy use and promoting the use of more environmentally friendly construction materials. Greening the B.C. Building Code is one of the extensive steps being taken across government to meet the Province’s target of reducing greenhouse gas emissions by at least 33 per cent below 2007 levels by 2020. |
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Money no object to save planet, say Aussies
By DANNY ROSE - SMH
Sunday, 31 August 2008 | ||
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A major survey of Australians' views on climate change has found an overwhelming majority think it is happening and they're prepared to pay to address it.
The study by University of Technology Sydney found Australians wanted to see cuts in the nation's greenhouse gas emissions irrespective of the actions of other countries. Researchers quizzed 768 people, who were chosen randomly but with a method to ensure the sample was reflective of the Australian population. The key findings include that 83.7 percent believed global warming was occurring and, of those, 84.9 percent said Australia should proceed with an emissions trading scheme (ETS) regardless of the international response. "The bottom line from this study is that Australians think now is the time to adopt a climate change programme that has some real teeth," visiting economics professor at UTS Richard Carson said. "They believe that climate change will cause serious problems in Australia and elsewhere in the world, and they understand there will be sizeable cost going along with it." On the question of what to do with the billions of dollars that will be pumped into the Federal Government's coffers by an ETS, Professor Carson said Australians voted for self-interest and also an increase in spending on research and development. "The lower income houses and seniors very strongly support [the Rudd Labor Government's] plan to redistribute the income to those households, while the middle- to high-income households … clearly support reducing the GST," he said. Professor Carson said 58.7 percent of participants supported spending 20 percent of ETS revenues on R & D, in keeping with a recommendation of the Rudd Government-commissioned Garnaut Review. "The public clearly favours spending 20 percent of the money on R & D … even though we told them that if they did that they would redistribute less money to the public," he said. "That shows the Australians are very forward-looking, they see it as a long-term problem and the R & D efforts will help them get over the hump." Survey participants' views were also sought on the different government plans and opposition policies to tackle climate change. A majority (57.1 percent) supported the government's plan to begin emissions trading from 2010 over the Liberals' later 2012 start date. Participants were quizzed on their political leanings and Professor Carson said Green and Labor voters were more likely to favour the government's plan. Interestingly, more than half (53 percent) of Liberal-aligned survey participants also favoured the earlier 2010 ETS start date instead of official policy held by the Federal Opposition. Views were split on whether transport should be exempt for the first three years of the ETS - with just over half (50.6 percent) for the move to temporarily delay price increases at the petrol bowser. The study, entitled Survey on Controlling Greenhouse Gases, was conducted by the UTS Centre for the Study of Choice. Professor Carson is a Professor of Economics at the University of California and is a Visiting Distinguished Professor at the UTS. |
London mayor unveils climate crisis plan
Fri Aug 29, 2008 6:00am EDT
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By Jeremy Lovell
LONDON (Reuters) - Mayor Boris Johnson unveiled a plan on Friday to help London tackle the challenge of climate change with less carbon dioxide, more trees, better drainage and increased water efficiency. Some 15 percent of London is deemed at high risk from flooding due to global warming -- an area including 1.25 million people, 480,000 properties, 441 schools, 75 underground and rail stations, 10 hospitals and one airport. At stake is an estimated 160 billion pounds ($293 billion) worth of assets, not just in London and its vital financial district, but all along the banks of the Thames estuary where vast new housing developments are being planned. "We need to concentrate efforts to slash carbon emissions and become more energy efficient in order to prevent dangerous climate change," Johnson told reporters at the iconic Thames Barrier flood defense system. "The strategy I am launching today outlines in detail the range of weather conditions facing London, which could both seriously threaten our quality of life -- particularly that of the most vulnerable people -- and endanger our pre-eminence as one of the world's leading cities." Global warming is expected to give London and its surrounding area longer, hotter summers as well as warmer wetter winters with the added problems of more frequent heat waves, droughts and flash floods from rising sea levels and downpours. Some 600 Londoners died as a result of the 2003 heat wave that killed about 15,000 in France alone, while low rainfall in 2004/05 led to water shortages in the capital. The plan, which builds on Johnson's predecessor Ken Livingstone's aim to cut London's carbon emissions by 60 percent by 2025, is to help the city prevent climate change, prepare for its consequences and recover from its effects. "London is not unique -- all major cities such as New York and Tokyo are at risk from climate change. By producing this strategy, we put London in a position of strength," Johnson said. He wants more trees to be planted around the city both to absorb excess rainwater and offer more shade from heat waves. Areas of the city at high risk of flooding must be identified and protected and the Victorian-era drainage system, which cannot cope with torrential downpours, must be extended and improved. But water shortages are also a potential problem -- the London area has less water availability per head than Morocco -- and water usage is above the national average. Johnson's plan calls for compulsory water metering which has been shown to cut consumption by up to 10 percent, homes to be made more water efficient and greater use to be made of rainwater harvesting. It also calls for urban designs that can cope with rising temperatures in a city whose centre is already on average significantly hotter than the surrounding area. (Editing by Mary Gabriel) |
Rush for water predicted
By PETER NEILSON - The Press Wednesday, 27 August 2008 |
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Most freshwater in all of New Zealand's major catchments will be fully allocated in just four years.
By 2012, in a country where snow and rain delivers 500,000 million cubic meters of water each year enough to fill Lake Taupo eight times over new investment will be blocked. A "gold rush" is underway to get access to the last of the water. Water seekers will be forced to queue, regional council catchment managers will impose moratoria on new consents and restrict the amount current water current users can take. At the same time the deterioration in water quality, from intensified land use, will continue. And in times of drought or shortages, the environment, recreational and other community uses will continue to suffer. It will come about because of New Zealand's system first-in, first-served system of allocating water. It served us well in the past. It still works in areas where there is a plentiful supply of unallocated water. However, in all the economically significant major catchments, including Canterbury, Otago, the Waikato, and in parts of Nelson-Marlborough, full allocation has happened or will happen in just 48 months. How has it happened? There has been a major intensification of land use since the 1980s. Nationally, about 95 per cent of the annual inflow remains in the natural water system to maintain ecological health and meet minor human and stock, firefighting, cultural and recreation needs. About 5% (679 cubic metres per second) is extracted by 22,000 individual consent holders for commercial use, mainly for farming: the so-called "abstractive" uses. Of this 77 per cent is for irrigation. The Canterbury region alone allocates 55 per cent of this national total volume of water. Of the rest allocated nationally, 11 per cent is for industrial uses, and 9 per cent for public uses (including drinking water). Between 1999 and 2006 the total amount of water allocated for abstraction grew 50 per cent. Canterbury has the majority of irrigated land (66 per cent) followed by Otago (14 per cent). Some catchments also face significant water quality issues. The central and regional government initiatives to clean up the central North Island Taupo and Rotorua lakes alone is costing $144.2 million. Water is essential for business. In fact, without it there is none: Just consider, it takes 40 litres of water to produce a slice of bread, 140 litres for a cup of coffee, and 2700 litres to make a cotton shirt. The potential shortages and prospects of worsening quality are concerning New Zealanders: 68 per cent believe fresh water quality is worse or much worse than 10 years ago; Seven out of 10 believe there is a water shortage or will be within 10 years; 64 per cent perceive agriculture and horticultural run off as the main cause of freshwater pollution. There is a solution though. In some waterways 20 per cent to 80 per cent of the allocated water is not being used. But the current system makes it difficult and costly to transfer that unused water to someone who needs and wants it. The New Zealand Business Council for Sustainable Development today releases the results of its $300,000 two-year research project, which proposes what it calls the Best Use Solution. It involves: * new national environmental standards and policy statements from the Government to set priorities for water use, and minimum national quality standards, guiding regional authorities on what's required; * integrated catchment management planning to accurately measure what is available and when, what is being used and discharged; * setting the amount of water available from waterways and aquifers to maintain the ecosystem, protect recreational use and cultural values, make sure there is sufficient for current and future drinking water supplies; * stipulating the amount available for commercial use. It is then recommended commercial users get a proportional of the water actually available in this "commercial pool", rather than a fixed amount. Much like the fishing quota system. Importantly, it also recommends better and extended use of RMA management tools to: * separately consent the take and use of water; * allow existing users access to water within catchment rules and contaminant limits set by the community; *introduce a mechanism enabling the re-allocation of surplus water on a voluntary basis to the most productive use. In this way, unused water already consented but surplus to requirements can be transferred to other consented uses; * introduce a cap on contaminant discharges and allow those to also be voluntarily transferred, thus maintaining or improving water quality. In this way, those not using allocated water can transfer it to others with short or long term needs. A Government-funded national consent registry is proposed to allow the transfer trade to happen in a transparent way. Significant takes and returns will be recorded. The Crown will continue to manage all water on behalf of all citizens. Aqualinc, the Business Council's principal external consultants on the project, estimate by allowing water to be used for its best use, there is a $1.8 to $3 billion of extra value could be added to the economy over the next 10 years. This is in addition to increased protection for the environment, cultural and community values. The country's quest to find better ways to protect our waterways, allocate what is truly available and do it more simply, quicker and at less cost, has been occupying policy makers for years. The Business Council worked with 19 organisations, and consulted another 14, including all major users, iwi, environmental, recreational and agricultural groups to produce the proposal. Not all will agree with everything in the Best Use Solution. But virtually ever water user believes the current system can't continue. The Business Council wants an in-coming Government to: * use the report as a platform to develop a national accord among water interests within 12 months, including any draft legislation; * trial the new system in a priority water-stressed catchment (most likely Canterbury or the Waikato); * Roll it out to other high-priority catchments. Failure has huge costs. A concerted effort at national and local level will have major rewards: The Taupo and Rotorua lakes' problems need not be visited on other catchments, higher-value use of water and economic growth can be achieved even in the most stressed catchments. And we will have a better chance of enjoying a better environment and secure use of cleaner waterways for all New Zealanders. Peter Neilson is Chief Executive of the New Zealand Business Council for Sustainable Development. Its 74 member companies believe businesses must be profitable to be sustainable, but also care for the environment and people. |
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Could $100 oil turn dumps into plastic mines?
Tue Aug 26, 2008 2:53am EDT
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By Kate Kelland
LONDON (Reuters) - Sparked by surging oil, a dramatic rise in the value of old plastic is encouraging waste companies across the world to dig for buried riches in rotting rubbish dumps. Long a symbol of humanity's throw-away culture, existing landfill sites are now being viewed as mines of potential which as the world population grows could also help bolster the planet's dwindling natural resources. "By 2020 we might have nine billion people on the planet, we could have a very big middle class driving millions more cars, and we could be in a really resource-hungry world with the oil price climbing and a supply situation in Libya, Russia and Saudi where natural gas is limited," said Peter Jones, one of Britain's leading experts on waste management. "It is those drivers, those conditions, which will encourage the possibility of landfill mining." In Britain alone, experts say landfill sites could offer up an estimated 200 million tonnes of old plastic -- worth up to 60 billion pounds at current prices -- to be recovered and recycled, or converted to liquid fuel. As many oil analysts predict oil prices will stay above $100 a barrel, waste experts in America, Europe and across Asia have been conducting pilot projects to recoup old plastic and other waste materials. Prices for high quality plastics such as high-density polyethelenes (HDP) have more than doubled to between 200 and 300 pounds ($370-560) per tonne, from just above 100 pounds a year ago, according to experts in the waste industry. With this in mind, leaders of the world's waste management industry are planning to come together in London in October for what is being billed as the first "global landfill mining" conference. "Once plastic is in a landfill site, it pretty much sits there doing nothing -- and the beauty of that is that you're able to go back and recapture it in the future," said Peter Mills, a director of waste and recycling company New Earth Solutions, who is scheduled to speak at the conference. "There are some really buoyant prices around because plastic is all manufactured from oil, so as the raw price of oil goes up, every commodity derived from it goes up accordingly." According to the Organisation for Economic Cooperation and Development (OECD), the amount of household rubbish thrown out across the world is expected to rise to about 3 billion tonnes a year by 2030 from 1.6 billion tonnes in 2005 -- or about 1 kg (2.2 lbs) per person per day in 2005. Many of the world's rich countries send about half of that trash to landfill, but the OECD projects that rate will fall to 40 percent by 2030 as governments promote recycling -- of materials such as metals, glass and paper -- or incineration to generate heat or electricity. "Over a period of a very long time -- many decades -- we have had a policy of burying whatever we can in landfill sites -- so there are valuable resources in those sites," said Steve Whatmore, of Orchid Environmental, a waste and recycling firm. "And wherever there are valuable resources, there is always the temptation to investigate whether its worth recovering them. The logic is sound, but the practicalities are complex -- and you have to balance those out with the commercial viability." FROM "SCAVENGING" TO "LANDFILL MINING" Landfill mining -- digging in dumps for valuable materials -- is hardly a new concept, and already viable for some. Images of poor, often homeless people scavenging waste to sell from landfill sites in Asia and South America have already provided evidence there is money to be made from other people's rubbish. William Hogland, a professor in Environmental Engineering and Recovery from the University of Kalmar in Sweden, also points to previous instances of dumpsite mining in Israel in the early 1950s where the soil -- enriched with rotting waste -- was recovered and recycled to improve soil quality in orchards. And certain U.S. states have since the 1980s mined waste from landfills to be used as fuel for incineration to produce energy. "Several pilot studies have been carried out for research or pre-feasibility studies in countries in Europe, but also in China, Japan and India," he said. For global waste experts, not everyone's rubbish is the same: different sites have different potential and an individual country's or region's dumps show characteristics relating to the culture, historical development and economic climate. "For example, landfills in Sweden dating from the 1960s have a lot of waste building material, reflecting the construction boom of that era," said Hogland. "And other landfills have very specific waste -- like those used by vehicle breakers -- which have high concentrations of aluminum, copper and iron scrap." "The value of these materials varies daily with global market prices, and today there is considerable demand for scrap metal from China, for instance." But in Britain, it is in the millions of tonnes of plastic that people threw out in a pre-recycling era that experts see a potentially lucrative future. That potential is clear to Chris Dow, managing director of the first so-called "closed loop" recycling plant in Britain able to recycle plastic bottles to a standard high enough for re-use as food packaging. Closed Loop London is one of only six similar plants around the world in Austria, Germany, Mexico, Switzerland and the United States and processes polyethylene terephthalate (PET) plastic, used for water and drinks bottles, and high-density polyethylene (HDP). It has the capacity to recycle 35,000 tonnes each year. A passionate recycler, Dow is convinced there is value buried in rubbish dumps, but angry that talk has turned to investing in technologies to harvest it rather than focusing on stopping more plastic from being dumped now. "Just imagine the resources that are lying in those landfills -- it could be incredible," he told Reuters. "But the insane thing is that we are talking now about investing millions into tapping into a resource under the ground, when the real tragedy is that every week we're still dumping tonnes and tonnes of plastic into more landfills. It's an act of vandalism against the environment." (Editing by Sara Ledwith) |
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Vermiculture key to reducing greenhouse emissions
Posted
Aug 20, 2008
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Researcher Dr Rajiv Sinha said vermiculture had potential to combat climate change by reducing emissions of greenhouse gases that plague current landfill waste management programs. "Methane and nitrous oxides from landfills are several times worse than CO2 as greenhouse gases," said Dr Sinha. Dr Sinha has spent the past 25 years in India and now in Australia studying vermiculture practices worldwide. He is now working to encourage governments, policy makers and landowners in Australia to adopt vermiculture on a commercial scale following the success of his trials in India where it has also enhanced the life of farmers. Two studies in vermiculture published this year in the UK in the journal The Environmentalist found worms were also useful in sewage treatment, or 'vermifiltration'. Worms reduced the biological oxygen demand loads by over 90% and total solids by 90–95%. "There is no ‘sludge formation’ which is a biohazard, unlike conventional sewage treatment plants which need landfill disposal at high cost. This was an innovative study made at Griffith University." A second study supported the efficiency of worms at removing heavy metals, pesticides and organic micropollutants from soil, a technique know as vermiremediation. "This has significance in Australia as large tracts of arable land are being chemically contaminated due to mining activities, heavy use of agro-chemicals and landfill disposal of toxic substances," Dr Sinha said. He is currently studying the potential of greenhouse gas emissions from various composting systems with Dr Andrew Chan in a project done by Honours student Richard Middleditch. He is also studying the growth promoting values of earthworms and their vermicompost over conventional compost and chemical fertilisers. "Our glasshouse studies showed vermicompost is three to four times more nutritious than conventional compost and takes nearly half the time to produce, while a field study by farmers in Argentina found it 5–7 times more nutritious.
Dr Sinha has completed trials on wheat and vegetable crops such as okra and eggplants in India and on corn crops in Australia alongside chemical fertilisers and conventional compost, and is now testing on tomatoes. "Wheat crops grown on vermicompost @ 2500 kg/ha gave yield over 4000 kg/ha whereas those on full doses of chemical fertilisers was about 3400 kg/ha. On cattle dung compost @ 10,000 kg/ha – four times that of vermicompost – the yield was just over 3300 kg/ ha. "In Australia we send thousands of tonnes of organic waste to landfills, which is an economic and environmental burden for society. "Political will is required to integrate waste management with organic farming programs promoted by vermiculture. We have known the benefits of vermiculture for centuries. We now have the scientific data to prove it." |
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Soil Association chief calls for organic change
August 31st, 2008 by Wayne
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The Soil Association should consider abandoning the use of the term “organic” because it risks putting too many people off, Monty Don, the organic certifying body’s new president has said. Instead, the term “sustainable” should be used.
In his first newspaper interview since officially taking up the post, the former Gardeners World presenter has called for the association, the UK’s biggest organics organisation, to tackle the common perception that it is “for wealthy, middle class people indulging in their penchant for peasant food”. “Organic is loaded with a sense of rightness, with a set of rules. We’ve got to move away from making people feel lesser because they’re not [eating] organic,” he said. “There is no doubt about it that sustainable is a better expression for the same sorts of ideas than organic.” Don, who has spent the summer recuperating at his home in Herefordshire from a minor stroke, is keen to see the association move beyond its current role as a certifying body for organic food by expanding its campaigning duties and helping the UK’s 11 million gardeners to grow more of their own food. Don believes the association risks being hindered in this task if it cannot shed its public perception of catering for the wealthy few. Yesterday, the Guardian reported that sales of organic food have fallen by a fifth since February, as the economy stutters. |
Quote of the week |
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Water and air, the two essential fluids on which all life depends, have become global garbage cans. -Jacques Cousteau (1910-1997) |
Technology Corner
Second generation tidal turbines promise cheaper power
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Harnessing the vast energy of the UK's coastal tides could become much simpler and cheaper with a new design for the next generation of underwater turbines. The device, unveiled by a team of engineers from Oxford University, re-thinks the way power is generated underwater and the inventors believe it will be more robust, more efficient and cheaper to build and maintain than anything in operation today.
There is an immense potential resource of clean energy from the tidal flows around the UK: conservative estimates suggest there is at least five gigawatts of power, but there could be as much as 15GW, equivalent to 15 million average family homes. Tidal generators can harvest the energy of these moving streams, with the added advantage that the resource is, unlike wind, predictable. There are only a few underwater turbines in operation today and they all operate like underwater windmills, with their blades turning at right angles to the flow of the water. In contrast, the Oxford team's device is built around a cylindrical rotor, which rolls around its long axis as the tide ebbs and flows. As a result, it can use more of the incoming water than a standard underwater windmill. At full size, a Transverse Horizontal Axis Water Turbine (Thawt) rotor would be 10m in diameter and 60m long. Connecting two of these together with a generator in the middle could produce around 12MW of power, enough for 12,000 average family homes. "To do that, you only need three foundations and one generator," said Martin Oldfield, senior research fellow of engineering science at Oxford University. "To do that with a [windmill] would require five foundations and 10 generators." The Thawt device is mechanically far less complicated than anything available today, meaning it would cost less to build and maintain. "The manufacturing costs are about 60% lower, the maintenance costs are about 40% lower," said Malcolm McCulloch, head of the electrical power group at Oxford's engineering department. So far, the researchers have successfully tested a version of Thawt that is 1m in diameter and 6m long. They are now planning to build a 5m-diameter test device that could generate electricity for the grid. By 2009 the team wants to carry out sea trials to test the device's durability in open water. Scaling up the power at a coastal site would involve connecting together a series of Thawt rotors across the sea floor. The engineers said that, if all went well, farms of Thawt devices could be built starting around 2013. "If you have a tidal site of 20km, you could build 20km of these turbines going across [the sea floor] and then you would be into the gigawatt class," said Oldfield. This would make the farm equivalent to a small coal-fired power station. McCulloch said that their economic analysis of the Thawt device showed that, at farm scale, the Thawt devices could be installed at around £1.7m per MW. That compares with around £3m per MW for modern marine turbine technology and just over £2m per MW for wind power. Doug Parr, chief scientist at Greenpeace said the UK is a potential global leader in wave power. But he noted: "Many good ideas for wave power generation suffer from a lack of finance, lack of assured market and lack of access to business expertise. "Some of these bottlenecks need to be addressed by the industry - others need government to play a boosting role rather than hoping that the rules and organisations that got us into the climate problem are going to be the ones that get us out." In July, Bristol-based company Marine Current Turbines installed the SeaGen device, an underwater windmill device, at Strangford Lough in Northern Ireland. It is the first commercial-scale tidal device to generate power for the grid. When it is eventually running at full power, MCT said it will have an output of 1,200 kW, enough for about 1,000 homes. "There are presently tidal devices undergoing testing – we regard those as first generation device and we regard ours as a second generation," said Oldfield. "To some extent we admire them for being pioneers of the technology but we think what we've got will end up being better." Steph Merry, head of marine renewable energy at the Renewable Energy Association welcomed the Oxford team's work but said that, in terms of backing a technology to harness tide power, nothing can be ruled in or out. "We've got this 15% renewables target for 2020 to achieve, which equates to 40% electricity, so you have to look at all possible options of generating it." Merry added that, technology aside, there were other stumbling blocks in building tidal projects around the UK, including what she sees as an excessive need to monitor the environmental impact of turbines. "We have to get it in proportion, you can't have an unlimited budget for environmental monitoring when every engineering company has to work to a budget for any project. At the moment, there is no limit to the monitoring that can be imposed." She said that the industry had to sit down with environmental groups and government to find a balance between the need to tackle climate change and the requirements to safeguard the ecology of tidal areas.
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