What do I think, What can I do?

Archive for 2012/07/12

Photovoltaic cells in our windows?

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Old photovoltaic cell

Most of the energy we use comes from the sun, even if we are not too conscious of it.

Different kinds of solar energy are the most evident example, but the wind is also moved by the energy injected in our atmosphere by the sun, as well as the water of rivers and lakes. All biofuels are generated by photosintesis diven by sunlight and even the fossil fuels were produced that way millions of years ago. They are so energy rich because they concentrate the accumulation of energy in organic compounds produced during a long period of time.The exceptions to energy coing from the sun are only nuclear and geothermal.

So it is not strange to think that the Sun should be our main target to find the solution for our climate change problem. But it is not so easy. The whole earth receives a huge amount or solar energy in form of light but it is not so concentrated, and consequently not so easy to extract and use practically. For this reason photovoltaic cells have evolved slowly for many years (and because of lack of investment and production effort).

Nevertheless, knowadays there are many technological improvements in the solar field that could lead us to a successful energy revolution. The most real one is the steep reduction in price of standard photovoltaic cells, with this trend grid parity will be out of dicussion in many places in short time.  But it does not stop there, Heliatek german company says it is able to produce semitransparent cells (link in Spanish) able to be located in windows with sufficient efficiency even at low light conditions and not affected by heat. This would be very interesting as the integration in the buildings could be straightforward, the only problem is the the price is not mentioned. How expensive will it be with respect to the energy produced? I know a tall house near here with a whole surface of glass, it could be a terrific power station. Sometimes it is not the optimun solution what succedes is just a reasonably good one in the right place and right moment, we will see.

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Small Great things

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1ºC is 20 m, sea level rise

I read this post recently and found it a terrific explanation of one of the most direct and frightening consequences of climate change: sea level rise. (I also bought his book High Tide on Main Street but I will try have to read it later).

One of the figures he gives is the best summary for me: Roughly sea level raises 20 m for each ºC, based on historic data. It does not happen immediately, the huge ice sheets need time to thaw but once the temperature is fixed it is unstoppable. Considering a moderate target of 2 ºC for our future warming if we do things relatively well and stop current business as usual in a reasonable time, this would lead to a terrifying figure of 40 m sea level rise. Others sources mention basically 21st century predictions as this article ( Antonio Zecca, Luca Chiari, Global and Planetary Change.). It calculates a lower limit of 80cm this siecle and more for the next 200 years; or the NOAA, witch estimates between 20 cm and 2m.

The problem to solve in order to predict the sea level rise is very complicated. Even knowing the exact amount of water coming from Greenland or west Antarctica, or the exact temperature rise and subsequent water dilatation it would be complex as the seas are filling the land floating in the magma. So, we have to be conscious or the great error margins and the difference between coasts.

But anyway, going back to the 40 m, I think my house would be included there, some years ago, in some floods just 3 m were enough to reach the lower floor, so I will not be here to see it but it could be sad to my grandsons to say this part of the sea was our grandfathers house.

A long time before that, with much less, it is likely that some housing market will realise about that and the wonderful coastal second houses or investment values will drop sharply causing an economical and maybe financial crack, and even before the strong storms will become a great problem for inhabitants owners and insurance companies.

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Interesting Consequences

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