What do I think, What can I do?

Posts tagged ‘coal’

2016 in climate change

I have been quite absent from this blog last years but not from Climate Change news, so I dare to give an opinion about 2016.  2016 was the hottest year on record, it was confirmed by all agencies, NASA, NOAA, WMO,… It is true that “el Niño” effect helped a lot but breaking global temperature records in 2015 and 2016 confirms that Climate is changing and it is changing now and fast. And this, although expected, is really bad news because it means that we have less time left to reduce our CO2 (and some other GHG) emissions.

2016 Hottest year on record, figure from NASA.org

 

 

 

Maybe a positive influence is that skeptics do not know what to say after loosing their hiatus argument, they will come back with it in some time. Nevertheless they are happy because one of them in in the White House and nobody really knows how much he can hinder Climate Change fight (some even consider he can be positive). I think that having a man that doubts about climate change ruling the most powerful economy in the world in years that are critical to get a real and serious global climate agreement is, definitively,  a problem.

To end positively, two important good news: a record new renewable energy capacity was added last year (with lower costs); and coal was passed by renewables worldwide. A good example is brexit UK coal use reduction, historical in the country that started industrial revolution with it.

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EROEI, another strange word

I recently met twice this interesting concept, EROEI, I do not intend to give a better definition than wikipedia so I quote it:

energy returned on energy invested (EROEI or ERoEI); or energy return on investment (EROI), is the ratio of the amount of usable energy acquired from a particular energy resource to the amount of energy expended to obtain that energy resource

The easy and rough way: how much energy you need to get a unit of energy.

  • How much energy is neccessary to drill holes for getting oil, and then tranporting, refining,.. before final consumption in form of gas.
  • How much energy is needed to build a wind farm and the electricity net associated.

I like this concept because it is very physical and physicists love those things. Apart from that it is something that does not depend on economic circumstances or the influence of big companies in prices, or subsidies… The economy is more prone to account for short term interests and factors, so a more pure measurement system to compare different energy sources is welcomed. Of course it does not substitute the actual prices because nobody will accept it straightforward but it is another tool to takelong term decisions and understanding what’s going on. These 3 links go deeper in that concept, here, hear, and here. And finally this article in neofronteras that explains it very clearly in Spanish, as usual in that blog.

The calculated EROEI valujes range from 100 for oil almost in the surface to almost 1 or even less than one values for cases where the needed energy is more than the obtained.  It is considered that values below 10 are doubfully profitable and cases close to 1 should not be profitable at all but could be due to econonomical circunstances. Another factor is the time, that is not considered in this calcaulation and has led to other indexes as EIRR (last figure).

However, actual EROEI figures are not as pure as the concept and differ seiously from one source to other, you can check it in the figures below. Wind mills are ussually in the 20 values, quite good, there is also a coincidence about the lowering value of oil, but nuclear and coal prsent several different values. Photovoltaic is ussualy near the 10 limit. I do not know the cause of the divergence, I suppose it is not easy to calculate or maybe the same factors affecting energy economy are present here too, I will have to check it better.

At least, I agree with the idea that in the long term it is difficult to maintain a cheap low EROEI energy system, it would not be sustainable in any sense.

Another EROEI calculation, source, Searching for a miracle, but obtained from neofronteras.

Some EROEI calculations , source: Wikipedia

EIRR and EROEI from ococarbon.wordpress.org

EIRR and EROEI from ococarbon.wordpress.org