Monday, January 31, 2011

Energy Saving: Some Successful Examples

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The previous post has pointed out that efficiency and saving are the keywords towards the solution of the energy questions worldwide.

The following video shows how a common task, heating a building, can be faced with a clever and sustainable approach. The good example comes from the Stockholm central train station which hosts about 250.000 people per day. As a human body radiates on average like a 100 Watt light bulb, each of us turns out to be a heat generator. The amount of thermal energy we transfer to a specific environment (for instance the train station) is given by our average power times the time we spend in such environment.

The idea developed by the Swedish company Jernhusen is that of collecting the excess heat produced every day by 250.000 commuters and transfer it to the nearby office block which, instead, needs a source of heat in the cold winter. Certainly heat transfer requires some electricity consumption but the latter is reported to be much lower than the thermal energy saved by heating the offices using the transferred human heat. Then, if the input is much lower than the output, the whole process is worth to be done.

The method is clearly explained at this link.

Meanwhile the sun is shining at my place and, as usual in such sunny days, there is no need for me to burn firewood in order to heat home. Only after sunset the efficient wood burning stove will be lit. Of course water is heated by sun thermal energy while electricity is generated by sunlight which is more than sufficient year-round. As I have been doing in this way for twelve years the notion of Passive System (given in the previous post) sounds quite familiar to me. Even obvious.

Every building can be energetically close to self-sufficiency if just a little bit brain is used in building it.

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