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Solar Tree Bears Fruit

Posted by Soulskill on from the functional-art dept.

Hugh Pickens writes "A prototype solar tree that recently went on display on a busy street in Vienna, Austria has passed a key test by providing light during the night-time even when the sun had been blocked by clouds for four days in a row. The branches of the solar tree were decorated with 10 solar lamps, each one powered by 36 solar cells. The tree included rechargeable batteries and electronic systems to measure the amount of light in the atmosphere and trigger the solar lamps to go on. 'Not just trees but other objects could be decorated with solar cells and so keep streets well lit at night time,' said Christina Werner from Cultural Project Management. Google uses a similar concept to light their parking lots with 3,000 solar panels that provide up to 10 percent of the Googleplex's power demand. We discussed Google's solar initiative last year."

6 of 106 comments (clear)

  1. The question is... by Anonymous Coward · · Score: 3, Insightful

    How much non-renewable energy does it take to produce each solar tree?

    1. Re:The question is... by NorbrookC · · Score: 4, Interesting

      How much non-renewable energy does it take to produce each solar tree

      If that were the only energy concern, then you'd have a point. It probably does take more energy in the beginning to produce it. However, the better (and more relevant) measure is total energy consumpption over its lifespan. That is, compare the manufacturing energy + energy use from grid + maintenance (replacement bulbs, etc.) over its projected lifepan to a standard lighting system. If it turns out that the overall energy used is less than that of a standard one, you come out ahead. You could also do cost analysis, but any pilot system has a much higher cost than production systems.

    2. Re:The question is... by MindStalker · · Score: 4, Insightful

      You also need to factor in the public safety benefit of it working even if the electricity is out. A whole city that stays lit up during a disaster could be very beneficial.

  2. Solar Electric Baobab Tree by G4from128k · · Score: 3, Insightful

    With a few minor changes, this "tree" could collect the rain water that runs off the solar panel and store it in its "trunk." Then, it would slowly release the water during the night to water the plants around the base of the tree. The result would save water and create a literally greener environment.

    --
    Two wrongs don't make a right, but three lefts do.
    1. Re:Solar Electric Baobab Tree by turgid · · Score: 3, Insightful

      Firstly, the water that reaches the soil when it's raining mostly flows over the surface and into drains. If it were stored and released slowly, it would be more effective at watering the plants since it would have time to penetrate the surface. Also, being released at night it would not be subject to evapouration caused by sunlight.

      I also imagine that these solar trees will function in all countries, not just Austria, or those in Western Europe.

      --
      Stick Men
  3. Very inefficient compared to grid-tied panels by originalhack · · Score: 3, Informative

    So long as fossil fuels are being burned to make power during the day, it is far more efficient to take the daytime output of the most cost-effective possible panels (usually nice unimaginative rectangular ones that mount on existing roofs or new carport structures) and feed it directly to the grid to reduce the load on the inefficient plants that peak during the daytime. There is no reason to lose a major chunk of the power charging batteries, to build expensive battery arrays or to build bizarre structures to support the cells.

    At night, the worst power plants are throttled back or shut down and the most efficient plants are handling the load.

    When no further fossil fuels are used to make daytime power, then storing electricity from daylight becomes interesting and, even then, batteries are a loser.