Category: Archive

Archived material from historical editions of The Generator

  • Industrial strength wind energy

    As reported in The Generator in December, a new approach to wind
    generation harvests more of the available wind energy through the use
    of a vertical axis turbine. This approach achieves better performance
    by capturing more energy in the first place and, as a consequence
    having smaller blades resulting in a lighter turbine, thus wasting less
    energy. The Economist this week reports that UK electricity generation
    companies are planning to use the technology at sea.

    TMA, a company based in Cheyenne, Wyoming, announced last November that
    its first vertical-axis wind turbine (VAWT) would soon be ready for
    commercial production, reported The Economist (11 March 2006, p.3).

    Pressure differential is created: The TMA system has two sets of
    vertical blades. The two inner blades, each shaped like a
    half-cylinder, catch the wind and rotate about a central axis, while
    the three outer blades, shaped like aircraft wings, are fixed. The
    interaction between the two sets of blades causes a drop in pressure in
    front of the rotating blades’ leading edges, which further increases
    the rate of rotation.

    Big efficiency gains claimed: TMA claims that its system
    harvests 43-45 per cent of the wind’s available energy; conventional
    propeller-style turbines, in contrast, have efficiencies Of 25-40 per
    cent.

    High wind capability: Furthermore, in winds of more than 80kph
    (50mph) the blades and gearboxes of conventional turbines cannot cope
    with the strain, and they have to be shutdown. TMA says its
    vertical-axis design can still work even at wind speeds as high as
    110kph, however.

    Quieter and less obstrusive, too: The ability to harvest
    high-speed winds is particularly valuable, since each doubling of wind
    speed results in an eightfold increase in available energy. TMA also
    claims that its design is quieter and less visually obtrusive than
    conventional turbines.

    Giant offshore turbines in offing?: A British consortium,
    Eurowind Developments, which includes VT Group, a shipbuilding and
    engineering company, and Mott Macdonald, a consultancy, believes VAWTs
    could be the best design for giant offshore turbines. Such a turbine,
    with a capacity of 10MW, would be able to power around 10,000 homes.

    Sheer scale of today’s blades is a problem: Today’s largest
    horizontal-axis turbines produce around 5MW, and are proving difficult
    to scale up. Each blade has to be more than 60 metres long, and the
    bigger the blade, the greater the stress it experiences as it turns:
    the blade’s own weight compresses it at the top of the cycle and
    stretches it at the bottom.

    Cost, efficiency penalties: As a result, blades must be made and
    transported in one piece, which is expensive. Reinforcing the blade to
    enable it to withstand these forces further increases cost and reduces
    efficiency.

    The Economist, 11/3/2006, p. 3

     

  • Burying CO2 necessary evil

    Australian Conservation Foundation sustainability program manager Erwin
    Jackson said the urgency of the need to cut greenhouse gas emissions
    meant the government should not wait for geosequestration technologies
    to come to market, according to The Australian Financial Review (16/3/2006, p. 5).

    Geosequestration tech useful: “But if it proves environmentally
    and technologically viable, then [geosequestration] could play a role
    in the transition to a truly clean energy future,” Jackson said. The
    greatest challenge to making clean coal technologies commercially
    viable is to bring down the cost of carbon capture.

    Regulatory framework for the tech: While there were concerns
    about the health and environmental risks of burying carbon deep
    underground, Jackson said he was encouraged by the work the mining
    industry had done with the Federal and State Governments to establish a
    regulatory framework for the technology.

    The Australian Financial Review, 16/3/2006, p. 5

  • Let’s give our gas away

    Federal Resources Minister Ian Macfarlane said on 15 March that “the
    underlying priority is to see Australia claim its rightful place as one
    of the world’s top five LNG exporters”, reported The Advertiser (16/3/2006, p.72).

    Australia still outside top 10: It was “currently still outside
    the top 10, despite our vast resources, but (growth had) to be backed
    by a solid domestic usage program”. The top five LNG exporters in 2004
    were Indonesia, Malaysia, Algeria, Qatar and Trinidad.

    Long-term industry framework: Macfarlane said a new
    industry-backed strategy was designed to make Australia more attractive
    to foreign investment through “a clear, longer-term framework for the
    industry that makes Australia as attractive a capital investment
    destination as we can responsibly make it”.

    APPEA plans to boost domestic use: The strategy would also focus
    on the domestic gas market, with APPEA targeting 70 per cent of new
    electricity generation to come from gas by 2015. APPEA said current
    domestic use for power was around 14.5 per cent.

    The Advertiser, 16/3/2006, p. 72