EcoRadio

Author: admin

  • Why 700.000 addresses face being washed off map

     

    Sea-level rise conjures up Pacific Islanders and Bangladeshis in dire straits, but few Australians appreciate it will hit some of the most valuable homes in this country. The legal advice coming from the State Government is that beachfront home owners will have to bear the brunt of the risk.

    The best hope of limiting sea-level rise from climate change is to cut global greenhouse emissions, according to the scientific advice. Yet yesterday prospects for an ambitious climate agreement in Copenhagen in December appeared to be dimming.

    As another round of preliminary United Nations talks ended in Bonn, the lofty goal for developed countries to cut emissions between 25 per cent and 40 per cent from 1990 levels by 2020 is looking remote. With Japan and the United States facing tough resistance at home from industry, a target of 15 per cent is now being discussed seriously.

    If that happens, the prospects of getting China and India on board to stop the soaring growth in their emissions will be even more difficult.

    Back home, the Climate Change Minister, Penny Wong, has yet to convince the Opposition and the Greens to support the Government’s emissions trading scheme, which is supposed to reduce Australia’s greenhouse gas emissions.

    If a less-than-ambitious climate agreement is the result, the evidence of climate scientists is that we will seriously increase the chances that the Greenland ice sheet will melt, bringing with it catastrophic sea-level rise.

  • Beachfront residents on own against sea rise

     

    Signalling the scale of future problems along the coastline from rising sea levels, Ms Tebbutt told Cr Hogan the Government would give priority to protecting public works and public safety, not private property.

    “Given the expected magnitude of requests for funding, government financial assistance to councils is unlikely to extend to protecting or purchasing all properties at risk from coastal hazards and sea-level rise,” Ms Tebbutt said.

    A senior official in her department, Simon Smith, bluntly told a federal parliamentary committee recently: “I do not think that many people have realised how significant it is and how much valuable land and property is going to be affected.”

    He also said: “The state’s view is that the risk to a property from sea-level rise lies with the property owner, public or private – or, whoever owns the land takes the risk. They gain the benefit of proximity to the ocean and they bear the risk of proximity to the ocean.”

    The NSW plan is being developed as scientists and councils warn that sea-level rise from climate change will greatly increase the number of beachfront homes at risk of inundation in coming decades, affecting some of the most expensive property in the country.

    Geoff Withycombe, of the Sydney Coastal Councils Group, said: “Coastal property values at present do not reflect their potential risk.” His organisation has has warned of a “black cloud of liability” hanging over councils.

    Yesterday some of Australia’s leading Antarctic climate scientists delivered a fresh warning to the Federal Government that “sea-level rise with associated effects, such as increased frequency of severe storm surges, will be one of the greatest impacts of a warming world on human societies”.

    The NSW Government released a draft policy statement on sea-level rise in February but councils and coastal property owners are only now realising its implications for beachfront properties.

    The policy is based on scientific advice that sea levels are expected to rise up to 0.4 metres by 2050 and up to 0.9 metres by 2100.

    Each centimetre of sea-level rise is expected to cause, on average, a metre of erosion along vulnerable coastlines. Sydney coastal councils were warned this week that the frequency of coastal flooding would increase by a factor of 300 if sea levels rose by half a metre.

    The policy will not be released until September. But residents with properties already threatened by natural or man-made erosion are pressing councils to protect their homes now.

    This week Byron Shire Council was in the Land and Environment Court attempting to prevent a beachfront resident erecting a rock wall to protect his home from erosion allegedly caused by early engineering works.

    The Mayor, Jan Barham, fears residents at risk from sea-level rise caused by climate change will sue councils unless the Government changes its plan.

  • British ‘searaser’ invention promises green power revolution on the waves

     

    Dubbed ‘Searaser’, it consists of what looks like a navigation buoy, but is in fact a simple arrangement of ballast and floats connected by a piston. As a wave passes the device, the float is lifted, raising the piston and compressing water. The float sinks back down on the tail of the wave on to a second float, compressing water again on the downstroke.

    What is particularly clever about Searaser, however, is its simplicity. Where most marine energy devices have sealed, lubricated innards and complex electronics, Searaser is lubricated entirely by seawater, has no electronic components and is even self-cleaning. Smith describes it as ‘Third-World mechanics’, but this belies the sophistication of the concept.

    ‘The beauty of it is that we’re only making a pump, and bringing water ashore,’ he explains. ‘All the other technology needed to generate the electricity already exists.’

    Searaser is designed to pump water either straight through a sea-level turbine to generate electricity, or up to a clifftop reservoir, where the water could be stored until needed, then allowed to flow back down to the sea through turbines, generating electricity on demand.

    The second option is the one about which Smith is most passionate. By effectively storing the energy generated by Searaser to be used on demand, his system would solve a problem that dogs almost all renewable technologies – their variability. Energy that can be summoned at will is not only more valuable, but also allows the grid to compensate for other, less easily controlled renewables such as wind and solar.

    Early trials of the prototype Searaser, one of which was completed in April, have proved encouraging. Despite being less than a tenth of the size of the version he hopes will eventually be supplying power to our homes, Smith’s homemade machine managed to pump some 112,000 litres of water a day during the trial, at times operating from waves a mere 6in high.

    The eventual machine will be capable of generating 1 megawatt of electricity – enough to supply some 1,700 homes – at prices that the team behind Searaser believe will be lower than most other renewable technologies.

    As an intermediate step, a trial of two midsize machines should go ahead towards the end of this year, with a university invited to monitor the trial and provide independent accreditation of the results. Although these machines won’t generate electricity (they will simply pump water through a flow meter to determine their potential) they will demonstrate whether the technology can work for prolonged periods and in rough conditions.

    For Smith, however – a man who could use a welder by the age of eight – the incremental steps between prototype and commercial deployment seem almost an irritation. His vision is already far advanced, and includes using the pressurised saltwater generated by Searaser to produce drinking water, using the same reverse osmosis process used in conventional, energy-hungry desalination plants.

    ‘All you’d have to do is reduce the size of the piston and increase the size of the floats to increase the pressure,’ he explains.

    He has also put plenty of thought into how he would persuade planners and landowners to allow him to build reservoirs on top of cliffs to provide the energy storage for Searaser.

    ‘The planning will frighten everyone,’ he says, ‘but if you were trying to produce as much energy from wind turbines, they’d be very visible; a reservoir you’d only see from above.’

    Smith has also put thought into how the reservoir could be made as water-tight as possible – vital to avoid saltwater leaching into soils. By double-lining the reservoirs and including an outlet pipe in between the two linings, you would instantly be able to see if the uppermost lining had a puncture by watching the end of the outlet pipe.

    ‘If you saw any water coming out, you’d know you had a leak and you could drain down the reservoir and sort it out,’ he says.

    Beyond being simply functional, however, Smith believes the reservoirs could be beautiful, providing recreational spaces for watersports or sites for shellfish farmers. ‘I bet the birds would love it, too,’ he adds.

    Although Searaser is clearly a commercial project and Smith hopes to see a return on his patents, he is also keen to see the technology deployed abroad, given that its simplicity lends itself to installation and maintenance in the less-industrialised world.

    ‘It’s a modular system: a community could start off with two or three machines, and expand as necessary. It can go round the globe, it really can,’ he says.

    • Mark Anslow is the Ecologist’s News Editor. This article appeared in the June issue of the Ecologist, part of the Guardian Environment Network

     

  • Carbon emissions threaten ‘underwater catastrophe’ , scientist warn

     

    And a separate paper in IOP Publishing’s journal Environmental Research Letters warned that increasing acidity in the seas could damage fish, corals and shellfish – leaving fishing communities facing economic disaster.

    The researchers from Woods Hole Oceanographic Institution, Massachusetts, said emissions from deforestation and burning of fossil fuels had increased levels of CO2 in the atmosphere by almost 40% above pre-industrial levels.

    Currently around 30% of the CO2 put into the atmosphere by human activities is absorbed by the oceans where it dissolves, altering the chemistry of the surface sea levels making it more acidic.

    The acidity can damage wildlife, particularly shell-forming creatures and the species that feed on them, with knock-on effects on people who rely on the oceans for food and livelihoods.

    Damage to corals could also reduce the coastal protection from storms that reefs currently provide.

    According to the US researchers, there were almost 13,000 fishermen in the UK in 2007, who harvested £645m of marine products, almost half (43%) of which were shellfish.

    In the US, domestic fisheries provided a primary sale value of $5.1bn (£3.1bn) in 2007, they said.

    The statement from the science academies of 70 countries, warned that despite the seriousness of the problem, there was a danger it could be left off the agenda at Copenhagen.

    The joint statement calls on world leaders to explicitly recognise the dangers posed to the oceans of rising CO2 levels, which it warns are irreversible and could cause severe damage by 2050, or even earlier, if emissions carry on as they are.

    Martin Rees, president of the Royal Society, said the effect of rising levels of CO2 in the atmosphere on the oceans had not received much political attention.

    But he said: “Unless global CO2 emissions can be cut by at least 50% by 2050 and more thereafter, we could confront an underwater catastrophe, with irreversible changes in the makeup of our marine biodiversity.

    “The effects will be seen worldwide, threatening food security, reducing coastal protection and damaging the local economies that may be least able to tolerate it.

    “Copenhagen must address this very real and serious threat.”

  • EU 37bn plan to power EU with the Saharan sun

    £37bn plan to power EU with the Saharan sun

     

    Vast farms of solar panels in the Sahara could provide clean electricity for the whole of Europe, according to EU scientists working on a plan to pool the region’s renewable energy.

    Harnessing the power of the desert sun is at the centre of an ambitious scheme to build a €45bn (£35.7bn) European supergrid that would allow countries across the continent to share electricity from abundant green sources such as wind energy in the UK and Denmark, and geothermal energy from Iceland and Italy.

    The idea is gaining political support in Europe, with Gordon Brown and Nicolas Sarkozy, the French president, recently backing the north African solar plan.

    Because the sunlight is more intense, solar photovoltaic panels in north Africa could generate up to three times the electricity compared with similar panels in northern Europe.

    Arnulf Jaeger-Walden of the European commission’s Institute for Energy explained how electricity produced in solar farms in Africa, each generating around 50-200 megawatts of power, could be fed thousands of miles to European countries. The proposed grid would use high-voltage direct current (DC) transmission lines, which lose less energy over distance than conventional alternating current (AC) lines.

    The idea of developing solar farms in the Mediterranean region and north Africa was given a boost by Sarkozy earlier this month when he highlighted solar farms in north Africa as central to the work of his newly formed Mediterranean Union.

    Depending on the size of the grid, building the necessary high-voltage lines across Europe could cost up to €1bn a year every year till 2050, but Jaeger-Walden pointed out that the figure was small when compared to a recent prediction by the International Energy Agency that the world needs to invest more than $45tn (£22.5tn) in energy systems over the next 30 years.

  • Atmospheric water generator

     

     

    Collecting water from the air has been a practice for some 2,000 years, in the form of “air wells” in Middle Eastern deserts, and later in Europe. Around the 1400s, we see water-collecting Dew Ponds, and later the Fog Fences, which have for hundreds of years have been used in Europe to collect clean water from the air. In the early 1970s, Melvin Littrell began producing water from the air with a system that did not need a compressor. Through this development, the creation of the first real Atmospheric Water Generator was produced. In 1990, Littrell patented the system’s technology as an AWG or atmospheric water generator.

    They are available in various sizes and styles, ranging from domestic systems that produce 32 oz. a day to all-electronic units producing 75 liters per day with compressors, and finally to commercial applications that can produce from 35,000 to 109,000 gallons of water each day.

    [edit] Principle of operation

    The principle of operation remains similar for most manufacturers except the WPG. The AWG is essentially a conventional dehumidifier that condenses water from air. A compressor circulates refrigerant through a coil or chiller array. A controlled-speed fan pushes air over the water reaction area and condenses the water. This water is then passed into a holding tank.

    The rate at which water can be produced depends on relative humidity and ambient air temperature and altitude. Relative humidity is the amount of water vapor present in the air at a given temperature at a given time. AWGs become more effective as relative humidity and air temperature increase. As a rule of thumb, AWGs do not work efficiently when the temperature falls below (35°F), the relative humidity drops below 40%, or at high altitudes (above 4000 feet). If the ambient air has passed through an air conditioner, much of the water vapor has already been removed. In the winter, with a heater on, most of the humidity is lost, leaving little for the AWG to produce.

    [edit] Optional AWG features

    AWG features vary depending on the manufacturer. In order to meet stringent FDA standards and NSF, most systems are coupled to one or more advanced filter systems (including an UV light chamber) before being stored in stainless-steel holding tanks. A list of optional features typically found in AWG systems would include:

    • An air filter to help prevent dirt from accumulating on the surface of the coil
    • An automatic level switch placed in the generator’s holding tank to shut the machine off when the tank is full
    • Hot and cold stainless-steel storage tanks that allow water to be served heated or chilled
    • The so-called “split system” is a two-part system. Designed by Prof. James D. Vagarasoto in 1991, the two-part system allows the user to place the generator in a location of high humidity and serve as a tabletop unit that dispenses hot or cold water. These systems eliminate the adverse effects of most older-style atmospheric water generators, as they heat the area where the generator is placed. In the summer, air conditioning system remove most of the humidity, so the conventional AWGs don’t work very well because they are humidity-driven.