By Sergio Beristain y Alvaro Silva Ordaz
Introduction
When we think about the benefits energy brings us we should pause and analyze its great importance in everyday life; this importance manifests itself in day to day situations with its simple presence. It is so important nowadays that it has become crucial for the development of human activity and consequently, for any society.
Great quantities of energy are consumed throughout the world on a daily basis whether it is electricity, solar energy, liquefied petroleum gas, natural gas, etcetera. The majority of these sources of energy are nonrenewable with a cost far greater and much more contaminating.
Over time, sources of nonrenewable energy will become the worlds greatest worry. For example, petroleum is produced from a chemical processes that takes place in the ground, a transformation that takes thousands or even millions of years to occur, thus an average sized deposit of this type is completely exhausted in just a few decades. What’s more the most important deposits discovered to date belong to a very small number of countries.
The main consequence of the scarcity of petroleum and the events that take place in the world concerning it is an increase in the cost of raw materials on the world stage. This is because the majority of transportation used to distribute merchandise is powered by gasoline. Any increase in the price of this resource is directly reflected in the power of acquisition of workers.
Similarly, consumption of petroleum over time indirectly creates large scale problems such as pollution, which in many cities has exceeded the permissible levels of particles suspended in the air causing respiratory illnesses in the most vulnerable of our populations and in some cases, even death.
It is worth pointing out that our country possesses many alternative sources of energy such as wind and hydropower. It is important therefore to substitute consumption of traditional energy for new energy generation processes using renewable sources of energy that offer additional services to users, encouraging job creation and channeling the resources obtained into the generation of electricity by way of renewable energy.
Encouraging the use of renewable sources of energy must be a priority in the different countries of the world, including Mexico, for economic, social and environmental reasons.
Renewable Energy in Mexico today
There is no doubt that our country is not a leader in the research and development of new ways to produce cleaner, cheaper energy. This is due to countless social, political, economic and cultural factors. Currently, we do not have a legal framework developed enough that is able to provide incentives to generation of renewable energy.
There are a number of promising signs that this topic will attract more attention in the future however, it cannot be left without discussion much longer. This is because our economy is in danger since the most important source of income for our country comes from the sale of petroleum and this source of energy could lose its importance if it is substituted by alternative sources of energy.
A good beginning may have been the 30th of December 2002 which saw the publication of the ENERGY FOR RURAL AREAS LAW published in the Federal Official Gazette. The provisions of this law are in the public’s interest and focus on aiding rural development in the country, establishing actions that promote productivity and competitiveness, which are measures aimed at reducing the asymmetry with respect to other countries.
This law has two important aspects to point out:
A) The ratio legis of this law has, in principle, a sound purpose to encourage development of farming activities in rural areas, such as agriculture, cattle raising, forestry, aquaculture and riverside fisheries, which are all relevant and in line with the national development plan.
B) The negative or poorly analyzed part is that the incentive to farming activities and primary production processes lies in granting low tariffs to the beneficiaries of this law. These stimulate consumption of nonrenewable energy, which primarily includes gasoline, diesel and fuel oil, without considering that these rural areas are ideal to begin generating renewable energy due to their geographical, climatic and regional characteristics.
Our country has signed and ratified the United Nations Framework Convention on Climate Change and therefore we have a commitment to the international community and our nation to reduce our greenhouse gas emissions. This gives rise to an urgent need to legislate on this topic.
If we want to achieve development of different forms of renewable energy in Mexico, the Energy Regulatory Commission, as the government body with expertise on the matter, must indicate guidelines in order to establish clearly and precisely the mechanisms for developing, encouraging and consuming renewable energy. At the same time, it must inform the population of the origin, use and benefit of these different sources of energy, and make them more mindful of saving energy whether it is renewable or not.
The study of diverse ecosystems and their characteristics in each region of the country may help to clear up the guidelines to be followed for the development of each state. For example, in northern Mexico, specifically in the desert regions, there is a very high ambient temperature during the day which suggests that this region would be suitable for harvesting energy from the sun by way of solar panels.
On the other hand, the Federal Government must create awareness in the population concerning the use and application of these new technologies to obtain renewable resources. It must apply a large proportion of the Gross Domestic Product in its Expense Budget to research and encourage their use since these investments would be useful in the short, medium and long term.
Plans to develop new energy technologies must be made jointly with the participation of both the Authorities and the Public and Private Sectors. The authorities have to provide essential support in quickly securing permits, licenses as well as in meeting other requirements placed on private investors, whether they be national or foreign, and attending to the complexities that a project of this nature might face in a timely fashion.
Thanks to price stability, technologies that take advantage of sources of renewable energy help to reduce future risks in our energy system arising from price variations in the cost of fossil fuels. This offers both short and long term benefits to the national economy.
It is foreseeable in the future that the need for resources will gradually decrease given that the cost of certain technologies that take advantage of renewable energy sources, such as wind and biomass, have dropped and will continue to do so.
Similarly, there is a new law under discussion in our country: EXPLOITATION OF RENEWABLE ENERGY SOURCES LAW, which would help to provide incentives for the generation of renewable energy in many different forms.
Renewable Energy New Alternatives
A source of energy is a resource or means capable of producing some type of energy for its later consumption. These sources can be classified as; primary, secondary renewable or nonrenewable.
Primary sources of energy are naturally occurring resources found in nature that do not need to be subjected to a transformation process in order to make use of their energy content. They are available directly (such as hydropower, wind and solar energy) or indirectly (after passing through a mining process such as petroleum, natural gas, mineral coal, etcetera).
Secondary sources of energy are derived from natural energy sources (primary) and are the product of transformation or manufacturing processes or in certain cases come from other sources of energy that have already been elaborated. The only possible origin of secondary energy sources in some kind of transformation center. This transformation process modifies the initial characteristics of the resource and may be physical, chemical or biological.
Secondary energy sources include electricity, the complete range of petroleum products, mineral coal and manufactured gas (or urban gas).
The group encompassing petroleum derivatives includes a wide range of useful energy products which are obtained from processing petroleum in refineries; among these we find gasoline, and fuels such as diesel (gas-oils) and others.
There are a number of methods available to create renewable energy; these include the wind, direct solar radiation, hydropower, ocean energy in its different forms (energy from tides or thermal gradients), wave energy, marine currents and salinity gradients, geothermal energy, energy from biomass or organic wastes or that coming from sugar cane and in general, all forms of energy coming from bio-fuels or renewable and intermittent energy sources, whose use is feasible in many cities in our country because of favorable cost-benefits. Any of these sources are capable of producing amongst others, electrical energy or electricity.
Sources capable of producing some type of energy classified as nonrenewable or exhaustible are coal, petroleum, natural gas, geothermal energy (internal forces of the Earth) and nuclear energy (the atom).
An energy source can be characterized as renewable when the processes that transform and exploit its useful energy do not consume or exhaust it on a human scale. These energy sources include: hydropower, solar, wind and the oceans. Additionally, depending on the way in which they are exploited, energy coming from biomass and geothermal energy can also be cataloged as renewable.
Renewable energy is often classified as being conventional or non-conventional according to the level of development of the technology that exploits it and its penetration into the market. The most widespread amongst conventional sources is hydropower used on a large scale.
Renewable energy considered to be non-conventional includes wind, solar, geothermal energy and that coming from the oceans. In addition, there is a broad range of processes that take advantage of biomass energy, which can also be cataloged in the same way. Likewise, small scale exploitation of hydropower is often classified in this category.
Because they are native and, depending on the way they are exploited, generate far less environmental impact than traditional energy sources, non-conventional renewable energy can contribute to energy policy objectives in areas such as steady supply and environmental sustainability. The magnitude of this contribution and the economic viability of its implementation depend on the peculiarities of each country, such as the potential for exploitation of renewable resources, their geographical location and the characteristics of the energy market where they will compete.
The following is a brief description of some of the alternative energy sources, which have been widely studied and employed in recent years.
Hydropower:
Among other phenomenon, solar radiation causes evaporation of water from the Earth’s surface, largely from the oceans. This water vapor accumulates in clouds that travel long distances to be deposited in the form of rain on mountains, many of which are far from the sea. This water accumulates in streams and by gravity, seeks the sea once more forming rivers. This volume of flow, which can manifest itself in great falls or strong currents, is the source of hydroelectric energy.
In many cases, the water is deposited in reservoirs and its potential energy is transformed into useable energy when it is channeled to lower levels. The moving water is used to turn spinning devices converting it into mechanical energy or to spin electricity generators. This can be applied successfully to any mountainous zone on the planet that enjoys regular rainfall.
Wind energy:
Winds are generated by differences in pressure caused by uneven heating of the Earth’s atmosphere, which results in large air masses moving from areas of high pressure to areas where it is lower. Approximately 2% of the heat from the sun that reaches Earth is converted to wind, but only a very small fraction of this can be exploited since much of this wind is found at high altitudes or over the oceans far out to sea. Additionally, certain levels of intensity and regularity in wind patterns are required to take advantage of them. Winds with average velocities of between 5.0 and 12.5 meters per second are considered to be exploitable.
The energy content of wind is kinetic (arising from the movement of air masses), which can be converted into mechanical energy or electricity by way of air turbines. These are mainly comprised of a tower, generator and some arrangement of blades.
Solar thermal energy systems:
Solar thermal energy systems can be classified into flat panels or concentrators or focusers. Flat solar panel systems or flat solar collectors are devices that heat up when exposed to solar radiation and transmit this heat to a fluid, which generally can be use to heat liquids up to 75º C.
Solar thermal systems that concentrate or focus sunlight work by concentrating direct solar radiation onto a focal area; they can be arranged around a single point or in a line. This collection of devices requires procedures or mechanisms for tracking the sun since the line of incidence varies throughout the day and year. These systems can achieve temperatures of hundreds of degrees centigrade and in special cases, thousands.
Photovoltaic Cells:
Photovoltaic cells are plates manufactured primarily out of silicon. When relatively small quantities of certain materials with very special characteristics are added to the silicon in the presence of sunlight, they create unique electrical properties. The efficiency in the level of conversion of these systems is around 15% which means that one square meter could provide up to 150 Watts of electricity, sufficient enough to operate a medium sized television.
To provide electricity during the night, photovoltaic cells require batteries to store the energy generated during the day, which makes using this system more costly. However, photovoltaic systems connected directly to the electricity grid are currently under development; this will eliminate the use of batteries and make the energy they generate immediately available to the user with the added possibility of selling excess electricity to the companies that generate it.
Energy derived from Fermentation:
Ethanol can be produced by fermenting and distilling alcohol which can then be used as a fuel directly or mixed with gasoline. Similarly, chemical products (such as vitamins, antibiotics, solvents and others) can also be obtained.
Sugar cane, sweet sorghum, fruit and beets are crops that are most easily converted into ethanol; the sugar, which is the basis of fermentation, can be obtained by pre-treatments such as pressing, cutting or washing the crops.
Some busses and trucks are able to operate on almost pure ethanol once their diesel motors have been adequately modified. An example of ethanol application can be found in Brazil where a great many automobiles burn this biofuel mixed with gasoline in proportions of roughly 60 / 40 respectively.
Biomass:
Plants accumulate energy by way of photosynthesis. Fed by solar energy, plants are able to separate carbon dioxide molecules, store the carbon as a type of hydrocarbon and release the oxygen. The level of efficiency involved in converting solar energy to stored energy in the form of organic matter (by way of photosynthesis) is very low and is estimated at a maximum of around 3%, although some forest species exploited commercially achieve conversion efficiencies of up to 1 %.
Energy derived from Sanitary Landfills:
Biogas can be produced from so-called Sanitary Landfills that contain a large amount of wet organic waste and foster conditions suitable enough for the proliferation of anaerobic bacteria. When these digest the waste they give off methane and carbon bioxide inside the landfill. Additionally, the wastes from this energy source can be used as a type of organic fertilizer for the soil.
Is Renewable Energy the Energy of tomorrow?
As we have already mentioned and considering the increasing awareness throughout the world to protect our environment, the use of renewable energy is coming closer day by day.
There are economic factors and vested interests throughout the world that are presently slowing the advance in the development of these new alternative energy sources, especially since petroleum is one of the main motors that drives the international economy. The scarcity of petroleum continues to provoke price rises, stock market crashes and even wars.
The solution to achieving balanced development in the world it to use these new forms of renewable energy since all countries would be able to generate energy by way of at least one of these sources, thus every nation would be capable of supplying its own energy without having to spend huge sums to obtain energy resources. Additionally, this would aid regional development and preserve the environment
