Windpower and sustainable landscape planning

Are the wind turbines a welcome addition to the landscape scenery?

Are the wind turbines a welcome addition to the landscape scenery? Do they make a useful contribution to sustainable energy policy? No and No. They are more like space invaders - and this example is mere tokenism.

I know of one excellent publication on the physics of sustainable energy David MacKay’s Sustainable energy without hot air (though his website suggests he lacks expertise in graphic design!). He calculates that ‘If we covered the windiest 10% of the country with windmills (delivering 2 W/m2), we would be able to generate 20 kWh/day per person, which is half of the power used by driving an average fossil-fuel car 50 km per day.’ Current energy consumption is about 125 kWh/day and MacKay calculates that, because of wind-speed variation, if the entire UK was covered with wind turbines it would be possible to generate 200KWh/day.  I do not think we should do this. The sensible steps towards more-sustainable energy use are (1) plan cities for cycle commuting (2) insulate buildings properly (3) tax bottled mineral water as heavily as alcoholic drinks.

But how can air conditioning costs be reduced in hot countries? Ideas welcome! Here are some suggestions (1) We used to have a refrigerator which was operated by dripping water onto a porous outer casing. The latent heat of evaporation cooled the inside.  Could this work for buildings? (2) In West Asia windcatchers (Persian: بادگیر Bâdgir, Arabic: بارجيل Baarjiil) have long been used for sustainable air conditioning. This is now the part of world with the best supplies of oil, but the technology could be exported  (3) apply even higher insulation standards than in cold countries, to keep the heat out (4) use heat pumps to refrigerate buildings – and generate electricity from the waste heat (5) use vegetation to shield the building from direct solar radiation

6 thoughts on “Windpower and sustainable landscape planning

  1. David MacKay

    Air conditioning by evaporation is indeed a standard technology in many countries. When I lived in Los Angeles I bought a “swamp cooler” which is a box containing a bucket of water and a fan. So your suggestion (1) is fine. Suggestion (4) [heat pumps] also works fine: a heat pump is a standard air-conditioner; but beware wishful thinking: – these heat pumps do NOT generate electricity from waste heat. Heat pumps that are doing air-conditioning use up electricity. They typically use about 1 kWh of electricity for every 4 kWh of “cold” delivered.
    All the best!
    David

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  2. Christine

    Item(5)and its derivatives are incredibly interesting from an architectural viewpoint. But I think it needs much more conceptual imagining before settling on the hard science! Or the hard science needs to be used in an iterative way.

    For example…the idea of atria needs some radical re-thinking in terms of the sort of space it might be and the uses it would be put to…. [http://architecture.myninjaplease.com/?p=559] See in particular The Helix Hotel [http://plusmood.com/2009/04/helix-hotel-leeser-architecture/]

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  3. Tom Turner Post author

    David, thank you for the clarifications. My thoughts are (1) there must be SOME USE for the waste heat thrown out by domestic air conditioning systems, just as there are for the massive quantities of ‘waste’ heat thrown out by server farms in cold countries (2) I would like to know more about the thermal consequences (ie cooling) of dripping water onto vegetated roofs in hot countries – and suspect that well before the end of the 21st century this will be the NORMAL way of managing a roof in hot countries.

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  4. Christine

    Waste heat has been dealt with in a variety of ways in commercial settings:

    1. Thomas More Square [http://www.tms-london.com/]uses a number of sustainability strategies which are technology driven. The waste heat from the office space is reclaimed using thermal wheels and used to pre-heat and pre-cool the air supply. [http://www.tms-london.com/#/2sustainability]. As does The Walbrook. [http://www.engineerlive.com/Energy-Solutions/Heat_Recovery/Air_conditioning_features_thermal_wheels/21810/]

    2. While the Donnelly Centre in Toronto uses atria and a double skin to ventilate heat and allow independent heating and cooling control to different zones of the building. [http://www.isdesignet.com/ArticleDetails/tabid/3339/ArticleID/3529/Default.aspx]As they say in the sustaining towers website [http://www.sustainingtowers.org/SOA-present.htm]:

    “Of course, the most interesting systems are those designed in such a way that in addition to permitting natural air circulation, they also use solar energy, converting it into electrical energy.”

    A each of these schemes raise a number of landscape questions…For example…So just what does the communal skygarden of Yeang and Dunster look and feel like?
    [http://www.sustainingtowers.org/SOA-present.htm]

    These principles can be adapted to the residential sector from bulk power generation [http://www.heat2power.net/en__markets_powergeneration.php]and with poetry [http://www.zeitgeistberkeley.com/powerplant.html] or with some simplification in the design of individual homes [http://www.zeitgeistberkeley.com/terrill.html].

    So the future?

    The greenbird concept is very evocative….but not yet the way we will travel to work!
    [http://www.engineerlive.com/Energy-Solutions/Renewable_Energy/Record-breaking_wind-powered_car_gives_a_glimpse_of_the_future/21861/]

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  5. Lara Hurley

    I had a student a few years ago who was from the Maldives. She did her dissertation on the use of green roofs and had some excellent research. She was trying to convince the government in the Maldives that it made sound economic sense to reduce the use of air conditioning by using green roofs and that simple, low-tech options were available.

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  6. Tom Turner Post author

    I am so convinced of the benefits of green roofs, to their owners and to society at large, that I believe the most urgent research projects should focus on why they are not part of almost every building in almost every country – as they surely will be by the end of the twenty-first century.

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