Energy
The availability of Energy is what allows us to live above our basic needs , take them for granted and to focus on “higher“ issues .
Running water, transport, heating, information and…. A long list of things depends on that availability. We often forget how many tasks energy does for us and how much our standard of living is based on its availability thus, how vulnerable it is .
Energy , any kind of energy, only works when it flows, when it turns from one type to another type of energy . For instance : from chemical energy stored in fuel to kinetic energy , from kinetic to electricity and then to heat at home etc. etc.
The easiest energy for us to transform , transport , distribute , and consume in the most efficient ways is electricity . Electrity is the most versatile type of energy; we can turn it into; light , heat , movement etc. . But electricity is not easy to store, we don’t know how to do that , at least not very efficiently. Electricity is produced and consumed at once. This fact leads to serious limitations.
The political , social economic and so on implications of energy are evident. So much so that we can use electricity as an indicator for many social measurements. General consumption, the type of power lines , the type of generation , etc. tell us many things about the community we are looking at , its standard of living, its politics and even its demographic distribution. The fact that you in English use the word “power” for electricity makes for many plays on words.
It is also clear that there are a lot of interests around energy . So the information spread about it is quite often manipulated by lobbies, blurred and tendentious.
To be truthful, quite often even those who seem to share the same ideas as me, contribute to the confusion because of the pressure from companies , investors , etc. that want to strengthen their position in the stock market, finances, etc. So that they publish that they have found “the solution”.
I do not believe in only one solution, I do not believe in only one answer to this challenge . I don't believe in it although it is one of the things I would most like to believe in.
Petroleum is really a strong competitor, it is amazing stuff in which nature has done a great job of concentrating energy, but the reservoirs are running low very quickly, environment can not stand its impact any longer, and the control of petroleum distribution is giving us more and more problems, and social and political conflicts . We have to get rid of that . We will keep on using petroleum but we cannot be its slave any more.
The desirable future regarding energy is complex and varied, many different sources spread out instead of a few concentrated ones. Now a days we have some technical chances and many more are coming if we have the determination to research and develope them .
But once again this depends on basing the values of our society on a different concept and this is a much more difficult challenge than any technological issue. Concentrated sources of power mean a useful way to get the power and keep it .
Hereinafter you are going to find a brief summary of available technologies
Practically all the electricity that we consume comes from rotating machines commonly called generators ( except a small part that comes from solar panels ) . To move this generator kinetic energy is needed, the more electricity you request the more energy you need, and the differences are from here on: Where this kinetic energy comes from.
The most common way is from thermal engines, burning fossil fuel: Coal, Oil, natural gas .
Coal was the combustible of the industrial revolution. It is the most abundant fossil fuel . There is no shortage of coal but it is highly contaminating , its combustion takes place at a very high temperature in a very specific way and in spite of every thing it has very harmful releases : CO2, Sulfur oxide, nitrogen oxide, etc.
It has made a strong contribution to the green house effect because of CO2.
Its mass combustion in power plants provokes acid rain because sulfur oxide and nitrogen oxide are released through the water in the atmosphere.
Apart from that, coal mining takes a constant toll of human lives, usually in third world countries.
There are many projects to improve the use of coal , like grinding it into a fine powder before burning it and then using it as a fluid but that isn't so easy.
Petroleum is almost as harmful as coal . Since some of its derivates can be refined its combustion is easier and cleaner but taking into account the general process, there are not many advantages .
Moreover the reservoirs are running low very fast and a lot of people from countries like China, India, Brazil etc. are joining us in requesting their daily portion of oil.
Oil has many other applications since it can be converted into many different materials thereby increasing the pressure on its distribution.
On top of that Oil is located in very specific places on the planet and our dependency on it is so big that it has given too much power to a very few people . I think comments are not needed about how they are using this power. In my opinion; we have to get rid of the slavery to oil and not only for environmental reasons.
Natural Gas : It was considered a byproduct in oil mining and it was just burned on derricks until second part of the twentieth century.
This fossil fuel has the cleanest and easiest combustion . It releases CO2 of course , as happens any time you burn any organic material , water vapor and a bit of nitrogen oxide
Its clean combustion allows it to be used near or even inside the consumption centers, with the advantage that in this case all the heat can be exploited . It is what is called cogeneration.
http://en.wikipedia.org/wiki/Cogeneration
In traditional generation only between 25% and 30 % of all the energy contained in the burned fuel is used, the rest is released as heat into the atmosphere, so the ratio between primary energy and final (useful) energy is as low as 25%. (no one takes advantage of more than 70% of the energy in the fuel (primary energy).
With cogeneration the rate between final energy (useful energy) and primary energy can reach 80% since the heat is exploited locally instead of being wasted. It is used for heating hospitals, public buildings ,air conditioning , industrial processes where heat is needed , etc. etc.
Cogeneration can be done with other fuels but it is not as easy and clean as it is with natural gas.
Since it depends on fossil fuel, it contributes to the green house effect and the reservoirs of gas are also limited, Cogeneration is not known as one of the sustainable energies, but it is pretty clearly of interest since it is the most efficient possible energy source, since it gets the most final energy with the least primary energy.
In my opinion cogeneration isn’t as glamorous as some “green energies” but it deserves to be taken into account.
Other thermal plants :
Bio-mass : Instead of getting heat from fossil fuel in biomass plants contemporary organic material is burned. It is alright in some cases, for instance; when local agriculture has byproducts to take advantage of , but I don’t think it is a good idea to grow specific crops to use then as bio fuel or bio mass . It is easily going to land up in exploitation and devastation of poor rural areas in the third world . I think it is much better they grow their own food in place of fuel for us.
Nuclear plants :They are also thermal plants, the only, (but important), difference being that they get heat from a nuclear reaction.
Under normal conditions they are clean and don’t release anything to the environment apart from hot water so their impact is low compared with any other.
Nuclear plants , at least the ones I have seen in Europe, are pretty safe. they have redundant systems. They have to be safe because in the case of losing control of the reaction the consequences easily can reach unmeasurable proportions.
It is also true that we don’t have a perfect solution to store the waste material from nuclear plants, which remain active ( emit radiation) for centuries.
Taking into account all the investment needed , the enriching process of nuclear fuel , waste storage, security measures needed, etc., nuclear power is not as cheap as it might look . The trick is; running a profitable business and transferring the problems; waste, safe transport of nuclear fuel, and so on, to society.
On the other hand Uranium 235 is not abundant enough to be the solution for energy scarcity.
Another side effect of nuclear power is that it makes it easier to have nuclear weapons because one of its “byproducts “ is plutonium. In summary we could say that ; nuclear power is a dangerous industry , pretty efficient but in no case can it be regarded as the salvation.
Sustainable generation:
Wind power; Among the “new” and sustainable sources of energy Windmills have been by far the most successful.
The Wind moves the blades and the blades move the generator , it's as easy as that. No emissions, no pollution, no fuel consumption . The impact is limited to the landscape and the noise of the rotor near the windmill when the wind blows.
It has become a big industry in Europe ; Germany is the first in wind power , Spain is the second or the third , followed by EEUU and China that will pass us because of the size of the country .
An enormous complex , wind farm , is being built now in and around the North Sea , with onshore and offshore mills . It is a huge project where UK, Germany , Holland , Norway, Denmark, Sweden, and others are taking part.
There is only one problem regarding wind power : We can't force the wind to blow, it blows on its own, not exactly when we need electricity , and we can't store electricity . Do you remember?
So it has to be connected to the grid, to other types of power plants that we can adjust more easily. So wind farms can't work alone, a reserve of available energy is needed to maintain grid stability.
Solar energy
Solar panels :
Basically there are two different types of solar panel :
Solar thermal panels : The most common type . They are usually mounted on roofs to provide hot water and heating . They are very efficient , they need a boiler or some other “traditional” system to support and guarantee the service under all weather conditions, but solar thermal panels save on fuel, emissions and as a result, money , so I don’t understand why they aren’t mandatory on the roofs of all houses in sunny countries like Spain or Australia….. …well I understand it but it is another long story. Simple and efficient .
Photo voltaic solar panel : They have been and still are a very good solution, in combination with batteries, for isolated spots, houses, farms , any place where power lines don't reach.
Not long ago these were the only applications for this technology but now a days it is getting more and more competitive and now private citizens who live in towns (Whoever is connected to the grid ) can take advantage of the surface of their rooftops and install panels for their own consumption and also sell the surplus energy to the grid ( no batteries required) .
To take full advantage of this system many changes are needed , some technological in the grid but above all many others in laws and regulations, if that were the case it could make a significant contribution to what is call distributed generation , always with other sources of power available to the same grid .
Solar thermal plants ( high temperature)
Basically the idea is to concentrate the sunbeams with hundreds of mirrors onto only one point , normally to a tower . The temperature reached at this point gets so high that it melts some salts and the heat accumulated in these salts can be stored for night time use and from that point on it works like any other thermal plant, the heat is changed into steam , like in a boiler , and the steam moves a turbine. Everything without burning any fuel .
You and I can point out many sunny areas in our countries and many others where these plants would work very well . Now in Spain there are some pilot experiences , some others are already working , and the biggest plant in the world is going to be built in Almeria.
This technology , together with wind power , is one of best answers to the challenge of getting sustainable energy with low environmental impact.
Apart from all these things you have to admit that it looks great.
Transport
Of all energy we use between 30% and 40% is devoted to transport of people and goods.
Now, to be brief I have to introduce a really useful concept when one is talking about mobility; The density of energy . It is the amount of energy of a given fuel per unit of volume and unit of mass.
When we set out the alternatives we have available for fueling automobiles, aircraft, etc. we have to keep in mind the density of energy of the fuels that we are considering .
Some data:
The density of energy of
Diesel 12500Wh/kg Battery li-ion = 160wh/kg ratio 80 times .
Diesel 10996wh/liter Battery li-ion = 300wh/liter ratio = 37 times .
Hydrogen 120.000kj/kg but only 0.08kg / m3(1000 liter) .
Hydrogen 33.333 wh/kg 2,3wh/ liter.
Well, data can be a drag . Let us go to the concepts.
A plane could be the best example since aviation is the field where this matter is most challenging. We can not load a plane with too much very heavy fuel because it has to fly, and we can’t fill up the whole fuselage with a light fuel because likely it is going to fly but.. then ……what for?.
Electric traction is very effective and efficient, it is also very elegant , no noise , no smoke, a charming way of driving ; No gear shift needed and it brakes by recovery. All the advantages but ……I remind you that now a days the systems to store electricity are still under debate although many of them are already being developed.
The big issue is : that if we found a way to store electricity for transport, it could be used to make the sustainable sources of energy more efficient and convenient . I remind you that wind blows when...... and sun shines when... …….
The car industry , which is very powerful , is perfectly aware that petroleum is running out, so they are trying to base their future on a new paradigm. They are pushing forward electric vehicles and the technology around them.
Saving energy is another subect; so important that it deserves it own chapter. On the other hand I have to cut off somewhere or I will never send it to you.