UNESCO Desire – Net project Sustainable Development Pietro La Mendola

1. UNESCO Desire – Net project Sustainable Development Pietro La Mendola pietro.lamendola@casaccia.enea.it UNESCO Rome, 2006 11 July

2. DOES ENERGY DISAPPEAR? Energy can not be created nor destroyed Words as “production” or “consumption” of energy, often used by technicians, are not correct and misleading.

3. ENERGY CAN BE TRANSFORMED We are able only to design, make or use tools which transform energy into a different form Words as “renewable”, “inexhaustible” or “clean” and so on, have been often used to describe new technologies regarding energy transformation

4. ENERGY AND NEW PROCESSES The progress of science promotes processes which transform the energy in a more efficient way Nonetheless, the total demand of energy to be transformed is increasing, as well as the number of potential users.

5. ENERGY IN THE PAST TIMES human beings were using the energy being already available as heat and mechanical work The energy use involved a lot of people and took an amount of raw materials from environment too large in comparison with the population.

6. THERMAL ENERGY INDUSTRIES Extraction, refining and working of metals; Baking of bricks, tiles and ceramics; Production of the lime; Manufacture of glass.

7. THERMAL ENERGY CIVIL APPLICATIONS Lighting of public and private buildings; Heating of buildings and cooking of food; Warming up of thermal waters.

8. NON FOSSIL FUELS Wood and charcoal; Vegetable oil coming from cultivation or gathering; Beeswax; Fat coming from hunting or bred animals (pigs, cattle, sheep, whales).

9. PROBLEMS OF “NON - SUSTAINABILITY” Exhaustion of materials because they are non renewable; Desertification of some large regions, and as a result, quickly alteration of local climate; Extinction of animal and vegetal species, or decrease of related population.

10. THERMAL ENERGY NATURAL SOURCES the natural low temperature sources of heat, such as solar and geothermal ones, were used in the place of combustion during low temperature processes: spas, tanneries, textile industries, dryer for food preservation

11. MECHANICAL ENERGY ANIMAL WORK The exploitation of animal work has caused for several centuries the use of great share of arable land as forage. Sanitary problems, dealing with animal excreta disposal treatment of dead animals carcases.

12. MECHANICAL ENERGY FROM NATURAL EVENTS the mechanical work being available for the human activities came from natural events. both wind energy and hydrodynamic energy are often used for navigation manufacturing plant. we were not able to transform energy,

13. the environmental changes, the fuel demand was very high The extraction of fuels from the natural environment without considering the cycle of regeneration. The extinction of big forest ecosystems and of their hydro geological and biological balances, The increasing use of fossil fuels (first of all the coal) was hailed as element of environmental safeguard by the Enlightenment epoch scientists the energy innovation started with the coal extraction activity. THE CONSEQUENCES OF NON FOSSIL BURNING

14. Concerning this purpose, it is necessary to consider: high reduction (per unit product) of thermal energy needed to metallurgy in the transition firewood – fossil coal the agriculture, once involving great part of mankind providing energy products, becomes an object of mechanization high energy content materials, limited number of workers THE CONSEQUENCES OF NON FOSSIL BURNING

15. Everybody can understand that according to mechanics (physics) energy quantity is equal: in 1000 m3 of water at 1000 meters height above mean sea-level or in 1 million m3 of water at 1 meter height. From a technical point of view, the transformation of mechanical power is different in the above mentioned cases because of the effect of obstacles deriving from fluid dynamics yield. ARE ALL KINDS OF ENERGY THE SAME?

16. Energy meant as thermal content can always be related to the temperature as index of its “quality”. Mechanical energy, in all its forms, can always degrade totally into heat, as well as the potential chemical energy and the electrochemical one, their limit achievable temperature depending on the transformation technology. We should consider the constant connection between the products of human activities and the converted energy in each working phase, also the accessory ones, for getting the end-products. Every manufactured good has required energy conversions; further energy has been turned for the transport and to allow the people’s activities who concurred for the working. ENERGY QUALITY

17. In many cases the energy consumption is regulated by entropy variations which are to be taken into account. For example, if a safe drinking water flow is imprudently mixed up with waste water flow at the same temperature, no energy conversion seems to be, but there is a strong entropy variation and a considerable amount of high quality energy needs to be converted in order to restore things as they were before. ENTROPY INCREASING

18. It is used to assess the rationality and efficiency of a community energy system. the used methods are complex. These methods need numerous iterations because of connections, which not always can be explained, among several energy processes. The result summarizing tables show the ratio of the converted energy for end-use, that needs: temperature heat < 100 °C temperature heat >100 °C and < 200°C temperature heat >200 °C energy turned into electrical or mechanical form END-USE TEMPERATURES

19. There are considerable differences between a country and another, regarding quality and quantity of converted primary energy. Differences are less if we consider the end-use of energy. Rationalization has a great potentiality. Furthermore, as time passes, the converted energy ratio for end-use, according to the different temperature levels, does not modify as expected. The reason of this trend is that research and technological progresses are more active in developed countries and in sectors involving higher quality and more expensive energy. RESULTS

20. In the last decades, the attention has being focused on the effects that energy models, based on the uncontrolled abuse of burning, can cause to the evolution of distribution of climatic zones in our planet. The illusion about regularity and immutability of climate is due to the short life of human being in comparison with the age during which climatic phenomena usually evolve. DEVELOPMENT AND VARIABILITY OF EARTH CLIMATE

21. We are not surprised if we find out, in the same geographic area and in different beds, fossils of animals and plants which are typical of savannahand polar climate animals. Observations of solar activities have pointed out that sun energy on Earth is subject to relevant variations of intensity depending on explosive phenomena of enormous proportions. DEVELOPMENT AND VARIABILITY OF EARTH CLIMATE

22. The main worry is from the risk of introducing, through human activities, a perturbation in well- balanced systems, but under conditions of “maximum”, compared to the sum of all forms of stored energy. According to the pessimistic hypothesis, these perturbations could affect the earth energy systems, that we are not able to describe mathematically for all possible interactions, leading them to conditions of progressive instability. This event could cause effects of divergent sizes, not proportional to the causes which have produced them, or even phenomena like “dominoes” acting in unforeseeable directions. RISK OF INSTABILITY

23. “Average temperature” would be a definable value if domain and moment were indicated calculating the mean. But temperature does not count the energy stored in the earth biosphere, for the following important elements: latent energy of fusion and vaporisation atmosphere pressure kinetic energy of air and sea waves wave and tide motion elevation saline unbalance GLOBAL WARMING AND “GREENHOUSE” EFFECT

24. Old and modern greenhouses working is based on solid panel able to transmit the radiant energy and to stop the transmission of the heath carried by the air convective motions. Nothing alike occurs in the earth’s atmosphere, where, except the mountains, there are no solid screens, and the motion of the mixture of gasses, solids and fluids constituting the air is unceasingly supplied through large amounts of energy. GREENHOUSES AND GREENHOUSE EFFECT

25. The considerable attenuation of thermal shocks caused by solar radiation, occurring in the surface of heavenly bodies without atmosphere, is due to a large number of mechanical, thermodynamic and thermo kinetic phenomena, among those the most important seem to be closely linked to water phase changes and to the stored energy as latent heat of vaporisation. GREENHOUSES AND GREENHOUSE EFFECT

26. In climatic environments where the relative humidity is very low, in fact, very high day-night temperature ranges occur making animal and vegetal life hard. The stabilising effect of atmospheric water is known even if it is not easy to calculate. In the vapour phase water is quite transparent through solar radiation in visible and thermal spectrum. In the solid microcrystallinephase reflects the most of thermal radiation. GREENHOUSES AND GREENHOUSE EFFECT

27. The daily transparency and night cloudiness enable the storage of solar energy in the atmosphere and the following energy conversions. CO2 of atmosphere can not work through the same physical schema because: It is a very heavy gas stagnating near the ground. It has a very low solidification temperature being not easy to reach, in the quota where it is. It is in the atmosphere in little concentrations in comparison with water GREENHOUSES AND GREENHOUSE EFFECT

28. CO2 is supposed acting through the selectivity of its range of emission - absorption that could let go higher frequency than solar radiation and terrestrial reflection, absorbing and turning the lowest frequency into thermal energy. We must say that carbon being on Hearth, through the CO2 component of the atmosphere, takes part in a lot of processes, one correlated to another, and not all of them are well known. GREENHOUSES AND GREENHOUSE EFFECT

29. Growth rate of vegetation will be higher if CO2 atmosphere content increases Each hectare of land changed to desert puts on the atmosphere thousands of tons of CO2 The metabolism of living organisms The vegetal life cycle and creation - destruction of humus The animal life cycle; production and disappearance of carbonates. For example coralline barriers. The mineral cycle of equilibrium carbonates - bicarbonates The equilibrium of solubility of CO2 in terrestrial waters depending on temperatures All combustions of material of living source and mineral reactions. INCREASING OF CO2

30. Fossil combustions and mineral dissociations introduce into the atmosphere a kind of different CO2, which can be distinguished from the one coming from other cycles, thanks to the absence of the C14radioactive component because of decay. Measures, aiming at highlighting the contribution of human activities in the increasing CO2 in the atmosphere, did not result successful, probably for the quantitative ratio with other exchange processes. CO2, AND RADIOACTIVE C14

31. Ratification of international agreements, about the reduction of fuel combustion and production of lime and cement, clashes with the objections of some nations: Who is sceptical about the success of the reduction and does not want a crisis for the economical system Who would take advantage of a possible acceleration of climatic changes INTERNATIONAL AGREEMENTS

32. Arguments supporting the two theories are a lot and not unselfish. It is sufficient mentioning the case of the recent banning of CFC, accused of the ozone hole, just at maturity of the related invention patents, and replaced with analogous compounds, perhaps less safe, but with new patents. The mass media interest in the ozone hole got exhausted soon afterwards. INTERNATIONAL AGREEMENTS

33. The strategy, or often the strategy absence, in the energy field, on which the economic politics of powerful states of XIX and XX centuries have been based, has been founded on the convictions that dominated the ancient world: limitless economic scenario continuous and limitless discovery of new natural resources infinite ability of the environment to receive human waste ability to impose the price of raw materials THE PROBLEMS THAT FACES US ABOUT THE ENVIRONMENT AND THE ENERGY

34. The economists and the scientists will have to begin to communicate correctly among them and will have to try to travel through new roads. The public opinion of all the nations, that have elective governments, currently have a greater sensibility to the environment than they had in past times and it can influence the choices of the governments ENVIRONMENT FOUNDED PARTIES

35. In past times the low technological level reduced the possibility to change type of energetic materials and to differentiate the supplying sources The different energetic materials had independent prices. The prices of the energy, deriving from a thermal conversion or from hydroelectric sources, were predominantly constituted by taxes and they were various in the different countries. DOES A REAL VALUE OF EVERY SOURCE OF ENERGY EXIST ?

36. The ability to employ various energetic materials of various origin has strongly increased a market of the energy in which the prices will be determined principally through the thermodynamic value and through effects on the environment of particular source of the energy and less and less through trade and fiscal relationships. The temperature of energy conversion obtained though burning process depends on the system technology. It can be much higher than the usually so-called "theoretical temperature of combustion". SOURCES OF ENERGY

37. The obtainable temperature through thermal type solar systems can be compared to that one that comes from heat recovery systems. The coming energy is directly usable as heat < 100 °C With solar systems able to concentrate the radiation, temperatures can be obtained, comparable to those of combustion process, similar conversion factor and economic value even if we are not able to foresee the impact on the environment. SOURCES OF ENERGY

38. Many international movements of opinion ask the governments to adopt environment political measures, oriented to cancel the modifications produced by mankind. The result of these provisions would be the restoration of the previous environmental conditions. TO RESTORE THE NATURAL ATMOSPHERE. WHAT AGE?

39. What we consider natural environment, because it is previous to the current excessive use of energy conversions, it often was already deeply modified by human presence as well as through natural phenomena. A correct approach is trying to achieve goals for planned modifications of the territory. It is hoped for consequences of the modifications in the long term which are foreseen and that we are able to correct the errors. TO RESTORE THE NATURAL ATMOSPHERE. WHAT AGE?

40. It is not possible converting energy without degrading a part of it into a so low temperature heat that it cannot be used anymore. On the other hand, the high enthalpy energy tends to be converted spontaneously and therefore every form of accumulation always is a danger. The greater is danger, the larger is the amount of accumulated energy and the higher is the enthalpy. ENERGY CONVERSION ONLY IF NECESSARY

41. We can consider: large hydroelectric river basins at a high altitude large deposits of combustible materials big tanks of high pressure compressed gasses etc. The most prudent behaviour about the energy problems is to help the use of kind of energy fitting to the aims and to resort to the conversion when it is the only solution. ENERGY CONVERSION ONLY IF NECESSARY

42. For example, the use of the energy as electricity is reasonable for: Motors Lighting system Communications Computer science ENERGY CONVERSION ONLY IF NECESSARY

43. On the contrary, it is not justified resorting to a cycle including the conversion of high temperature heat in electricity, losing beyond 60%, in order to make a second conversion in a low temperature heat: For example: electrical water heaters electrical stoves ENERGY CONVERSION ONLY IF NECESSARY

44. A different budget can be made when the energy as electricity is reconverted in order to realize thermodynamic cycles allowing to use heat supplies already available by raising the temperature. For instance, the heat pump systems of heating. Or electrical oven in comparison with those heated by fuel without thermal recovery like the gas kitchen oven. In cases as these, the conversion of the electricity in heat can be justified, since it takes part in a favourable total cycle. ENERGY CONVERSION ONLY IF NECESSARY

45. Concerning the sustainability, the energy transport permits to rationalize many applications. According to the current level of technology, the conversion in electricity allows the transport of energy with small losses and reduced dangers, in comparison with other transport system. ELECTRICITY AND HYDROGEN, ENERGY CARRIERS

46. The electrical net requires high investments in infrastructures, both economic ones and those of converted energy in order to construct them. In the electrical net there is no transport of materials, there are a few machineries in motion, and the episodes of interruption of the transport are frequent only if the net is excessively complex. ELECTRICITY AND HYDROGEN, ENERGY CARRIERS

47. Conversion in electricity allows storage methods with reduced capacity, high cost and low efficiency, dedicated only to the emergency systems. On the contrary, the situation, which some analysts foresee for a close future time, about hydrogen production for energy use, is different. ELECTRICITY AND HYDROGEN, ENERGY CARRIERS

48. The hydrogen is widespread on the earth, but it composes materials like the water with strong energy of chemical link. For the breaking of this linkage is necessary to convert very precious energy and the efficiency of this process is not very high. HYDROGEN FEATURES

49. Other disadvantages of the energy system based on hydrogen are: Low density, and consequently heavy high pressure tanks or large gasometers. Very frequent losses from tanks and piping. Hazard of flare-up High speed of climbing in the stratosphere and great chemical affinity with ozone. Demand for high pumping power in the pipes. Temperature of liquefaction very low <20°K. HYDROGEN FEATURES

50. The hydrogen is therefore an artificial fuel difficult to transport and to accumulate, it does not give emission of CO2 if is obtained from the water, but its use for the production of low temperature heat is unreasonable. It always offers interesting prospects for the possibility of inverse electrolysis if the technological problems connected to its manipulation are solved.. HYDROGEN FEATURES