«Un uomo è ricco in proporzione del numero di cose delle quali può fare a meno»
Henry David Thoreau, Walden, ovvero vita nei boschi

sabato 11 febbraio 2012

A winning energy strategy

Qui la versione in italiano

A winning energy strategy

From renewable energies to sobriety

Luca Madiai

Florence, January 2012

«The way in which the energy crisis can be defeated in wealthy countries is to throw out the illusion that well-being depends on ever increasing energy consumption»

Nicola Armaroli, Vincenzo Balzani

Today’s energy challenge is a big issue, we can hear people speaking about it in any place and at any time. In particular, every day we listen to some news about renewable energy development, a fast race towards green economy expansion. Although this is desirable, the methods and aims of this frenetic rush are not, in my view, the right ones.

The major focus is only on the annual installed capacity growth of renewable energies and the expected profits mainly of big business interests and for equally big power plants. Speculation is the real aim, large profits, not else. The energy efficiency, the real utility and the production of such projects are of secondary importance.

Anyway, instead of discussing further the reasons of my opinions, I prefer, and the readers will forgive me, to skip directly to the proposal of an alternative to address the current energy and environmental crisis, mutually related with economic and social crisis.

My proposal can be summarized in a simple diagram given in figure 1. It is based on four fundamental points, from energy source to energy usage. They are: renewable energy resources, conversion efficiency, waste reduction and sobriety.

Figure 1

The kind of energy source at the base of our society is a crucial choice for its stability, equity and well-being, three essential condition for a future of peace and happiness in all our world. Harnessing renewable resources is certainly a wise decision: they do not emit pollutants and carbon dioxide*, they are more or less evenly spread everywhere, they use local natural resources and they can be implemented in small plants locally connected for direct use. Any kind of renewable resource** can be developed to maximize its contribution, without forgetting its environmental impact. Too large power plants must be avoided because they are mainly operations of speculation, they have a huge environmental impact and are controlled by few entity. Local smart grids will be created with the goal of exchange energy among neighbors and reach best efficiency through sophisticated electronic control systems. Apart from the fact that costs are still quite high and their relative impact on the environment is not negligible, renewable energies have two main problems: 1) low energy density and 2) discontinuous and not fully predictable production (except for biomass and, in some cases, hydropower). The first issue will be discussed below. In order to compensate the discontinuity, renewable energies can be stored transforming them into other kind of energy: one example is the production of hydrogen that can feed fuel cells, combustion engines or even could be used, in a not too distant future, to power small cold nuclear fusion reactor.

Renewable sources are fundamental, but alone are not sufficient to create a winning energy system in order to overcome the triple crisis: environmental, economical and social crisis. They are only the first steps of our path, we must continue then.

Moving forward, any energy transformation involves energy losses of different types. Efficiency estimates how good is a transformation: losses can be decreased but they can never be zero, as indicated by the second law of thermodynamics. Hence, improving energy efficiency is the second step. Modern and advanced technology lets to reduce losses and to enhance new operation systems much more efficient and environmentally friendly while it can guarantee the same or better results. One example are the low consumption lamps, they light very efficiently and in the same time they significantly lower power consumption. Energy transformations allow natural energy sources to be converted in human usable energy (heat, electricity, fuels…) and the reduction of input available energy respect to output useful energy is described by the energy conversion efficiency.

There are mainly two limitations to the improvement of the energy conversion efficiency. One has empirical reasons, since it is supported by the laws of thermodynamics.

The laws of thermodynamics are of extraordinary importance. “They should be a basic part of our cultural background, like the alphabet, the multiplication tables, the Constitution and the Divine Comedy” as told by Armaroli and Balzani [2], they should be taught from primary school to even humanistic faculties. The first law says that in an isolated system no energy can be created, the energy of an isolated system is always the same. If we consider Universe, energy can be only transformed. That means that the energy of the Universe, even if it is huge, is a limited quantity. The second law states that energy in its continuous transformation inexorably deteriorates. That is the reason why every transformation is always related with thermal dissipation of energy and increasing of disorder (entropy) and it explains why the conversion efficiency can never be the best. Therefore, the energy conserves its quantity but not its quality.

The other limit for improving the conversion efficiency is the Jevons paradox according to which a better efficiency can lead to an increasing use of resource instead of reduction. This is due in part to lower costs and partly to a dreadful culture of no limits to our material needs.

These limits to the energy conversion improvement should not discourage research and development of new technologies and solutions, but should make us conscious that science and technology can not solve every problem that we have created and that a further step is strictly necessary.

These first two points, renewable energies and conversion efficiency, are surely important but the latter two are definitely more. Even if we would use 100% of renewable energies and very high conversion efficiency, we could not claim to have overcome today’s energy and environmental challenge. These latter points are essential but unfortunately nowadays they are almost completely ignored.

Thus, continuing our path after we have got useful energy, we have two choices: one is to use it and one is to waste it. Wasting refers to energy that does an actual work but that is not beneficial to anyone. Best example, to understand it better, is an empty room with the light on. Naturally nobody can benefit from the light, therefore the useful energy for lighting this room is completely wasted. I know it can be obvious and banal, but since in practice this is never taken into consideration, I have good reasons to believe that it is not so obvious and banal at all. In any case, it is an evident consequence that reducing or even eliminating the waste of energy does not reduce or compromise our benefits, there is no any influence on comfort and affluence, simply a wise use of energy, that is all.

In order to reduce the wasted energy we can act both technically and culturally, with a strong support of policy reforms. A large set of new and old, simple and sophisticated, cheap and costly technologies can be applied to save energy eliminating the waste in several sectors: buildings, energy distribution, transportation, private and public lighting, industrial processes, agriculture and so on. On the other hand, acting on people cultural change a lot of work can be done in the direction of waste reduction: stimulating education and awareness of people to the role of energy in our lives, its importance and impact on the society should be one of the first line in all the cultural and education programs together with the teaching of laws of thermodynamics and their related philosophy.

Returning to our diagram (figure 1), we realize that even the useful energy that is effectively used can be used in two principal ways: consciously or unconsciously. It is not only a question of pollution that is closely connected to energy conversions, of international political instability related to the supply of primary energy resources, or of related economical issues. It has been demonstrated in different ways that energy consumption per capita is not a trusted parameter to evaluate the quality of life in affluent country. «Several studies shows that people living in countries with high energy consumption are often less happy than people living in countries with lower energy use»[1]. That means there is a limit, more or less defined, beyond which there are no substantial improvements on quality of life: surplus of energy and wealth leads to increasingly severe uneasiness as well as to widespread unhappiness and “social disintegration”. We should free ourselves from the illusion that “more” is always better, that limits on our terrestrial life do not exist and that our wellbeing and happiness is related only on our material needs. In one word, we should become familiar with an old word today not very fashion: sobriety, that is it. Sobriety as life style, sobriety as philosophy of life and sobriety as new paradigm of human development and happiness seeking. Sobriety is the slogan that includes the individual awareness that the excess is physically and socially harmful, while the right amount has to deal with wisdom, self-control and respect and not with renounces or sacrifices.

When we take the car to make few meters in town, we are not using energy consciously. The same when we consume water in plastic bottles, or when we keep our house extremely hot in winter or cold in summer. In each of these cases, we are not aware of the impact of our daily actions and we are not aware of how valuable energy is.

After all, sobriety is to respect the limits, means thinking about life on a human scale, pursuing the correct dose, not the excess, neither scarcity, but the right balance, the middle way. It means choosing to take the stairs rather than taking the elevator. It means choosing to ride a bike instead of a motorcycle, or a tram instead of a car. It means to avoid the use of many energy slaves which assist our lives but do not always make them better.

In order to have a new indicator to evaluate energy management, from primary source to final use, we can define a new parameter called energy sobriety coefficient ESC. Such parameter is defined as the ratio between the primary energy available in a system and the corresponding energy used consciously as outlined in figure 1.

The energy sobriety coefficient is defined as an efficiency coefficient, since it describes how energy resource is used. It is a ratio between output and input quantity, it accounts the waste of energy during the entire process. The energy conversion efficiency can never be maximized as we saw previously, we will have always a loss of energy. Anyway this approach tries to maximize another important parameter: the effectiveness that measures the capacity of a system to reach a goal or to satisfy a need. It is calculated as a ratio between an output and an objective. Since we try to avoid any waste of energy and we use it only in a conscious way we have maximized the effectiveness, because we satisfy our need completely.

We have already said that one of the biggest disadvantages of renewable energies is their low energy density in terms of occupied area. The only really satisfactory way to compensate for such disadvantage is to adopt an energy sobriety policy together with a change of lifestyle and a profound change of way of thinking about life itself too. In my opinion, these choices could seriously lead our society to achieve the coveted goal of 100% renewable energies for electricity production. Such goal could be reached in such way in relatively short time.

The importance of these issues is unique and is growing with the deepening of the triple crisis in the last years. Besides the energy challenge, another imminent challenge is surely related to the global economy. Should now be evident to everyone that an economy based on consumerism and unlimited growth in a sensitive and limited world has nothing to do with wisdom and consciousness. Such a system is bound to collapse on itself. We should run to replace it with a sustainable alternative. Since energy is the basis of all human and natural activity, a winning energy strategy is strongly needed.

* Except for biomass that emits pollutions and CO2. Anyway this CO2 is not of fossil origin and can be absorbed by vegetation, without compromising the Earth’s atmosphere balance

**It is important to stress that the recovery of energy from the combustion of inorganic wastes should not be considered a source of renewable energy. The follow energy sources can be classified as renewable: sun, wind, geothermal, biomass, hydropower, marine.

[1] Armaroli, Balzani – Energy for a sustainable world – Wiley

[2] Armaroli, Balzani – Energia per l’astronave Terra – Zanichelli

Nessun commento:

Posta un commento