Abengoa :: Innovative technology solutions for sustainability

The world is suffering today from total dependency on fossil energies. Accounting for over 80 percent of global energy demand, if oil and natural gas were to suddenly stop flowing from producing countries to consumers, our cars, trucks, trains and airplanes would no longer run; goods would stop moving to and from factories; people would not be able to get to their workplaces, and our economy and society as a whole would be rendered utterly crippled.

Although fossil energy can take the credit for having contributed to propelling our planet toward its present degree of development, today it nevertheless poses serious drawbacks that dictate an urgent quest for alternatives.

The first of these disadvantages is the fact that the fossil energy consumed cannot be replenished; that is, it is not renewable. Fossil fuels are the product of accumulated remains of plants (forests and marine plankton) that lived millions of years ago and which have fossilized to form coal or hydrocarbons (petroleum and natural gas). Solar radiation, captured by plants and trapped throughout the geological eras in the form of high-energy molecules, is what is found today in the hydrocarbons generated from the decomposition of plant matter through exposure to temperature, pressure and certain bacteria over the course of millions of years. This is what makes fossil energy irrecoverable, and hence its inevitable depletion. It has been estimated that it will take no more than 70 years for oil to run out as an economically viable source of energy.

Secondly, there is the matter of the energy and economic dependency endured by oil-consuming nations. With the exception of the twelve countries that make up OPEC, the body controlling half of world crude oil exports and holding three quarters of the oil reserves, the rest of the world’s nations produce much less oil than they consume, and  they are consequently forced to import at the price dictated by the organization, which usually gives rise to intense economic dependency.

Thirdly, there is the problem of escalating climate change. The greenhouse gases produced by hydrocarbons upon combustion lead to alteration in the composition of our planet’s atmosphere, magnifying the natural greenhouse effect, and therefore making the temperature of the earth’s surface rise. In just a few years, this can lead to melting of the polar ice caps, a rise in sea level and ocean acidification, coastal and island flooding, resulting, consequently, in a severe economic and humanitarian crisis of global proportions.

Fourth among the drawbacks of fossil energies is their negative impact on the environment. Hydrocarbon production and transportation entail serious environmental risks, such as, for example, those stemming from oil spills or explosions. Furthermore, oil well exploration and exploitation are the cause of serious problems, including loss of biodiversity, ecosystem degradation and ocean pollution.

And, finally, the fifth problem is the high level of air pollution caused by fossil fuels. Burning gasoline in an engine not only gives off carbon dioxide and water in the exhaust pipe, but also generates by-products that pollute the air, such as carbon monoxide (poisonous), nitrogen oxides (smog producers), or hydrocarbons resulting from partial combustion (giving off noxious ozone that is hazardous to health).

We need to take a giant step forward to get beyond the present fossil-based economic model, replacing it with a model based on clean, renewable energies with a guaranteed supply. However, in order to achieve this, the change must be gradual, as the substitution of humanity’s chief source of energy will obviously have significant political, economic and social ramifications.

The first in the series of steps required is to include the environmental impact of all products and services in their cost. This is something economists have known about for a long time, technically referred to as negative externality ^[2]: by consuming a given product or service we generate third-party costs without there being any kind of interceding economic compensation. The way to resolve this is through internalization of this cost by making the consumer bear it, by creating, for example, an emissions market the cost of which is attributed to the goods and services of the business involved. If this were to happen, fossil energies would lose a large part of their competitiveness with respect to renewable energies, since their price would rise substantially due to the tremendous economic cost for everyone of the environmental detriment entailed by their use^[3].

After setting this new economic paradigm into motion, the change in economic incentives will give rise to a new model, the carbon economy, which will lead to exponential technological development of renewables. These energy sources offer the advantage of being non-polluting, free of greenhouse gas emissions, and having the capacity to reduce the political and economic dependency acquired with a handful of unstable nations that presently control the world’s oil. Many experts believe that solar power will prevail as the primary source of energy in the medium and long term. And it is quite likely that hydrogen will become the energy vector^[4] of the future, as a complement to electricity. The combination of the two will instantly eliminate 65 percent of our planet’s greenhouse gas emissions.

Solar energy boasts the advantage of being universally accessible (with the exception of the Poles), and unlimited in duration. In fact, covering less than five percent of our hot deserts with solar collectors would suffice to meet the electrical power needs of the entire world. Numerous alternative technologies are available today for producing energy from the sun. They can be categorized into two main groups. On the one hand, there is photovoltaic technology, which turns solar radiation into electricity by employing the photoelectric effect, and, on the other, we have solar thermal technology, based on turning the radiated energy into heat for subsequent use in a thermodynamic cycle. The use of one kind of solar technology or the other depends on the type of energy need involved. For example, in the case of supplying power to a large number of homes or industries located in an area with a high level of direct radiation, solar thermal technology makes sense, whereas as photovoltaic technology is a more sensible option for disperse population cores or for individual use.

In turn, in order for hydrogen to perform its function accordingly as the energy vector of the future, a few matters must first be resolved. The two most important issues to be addressed are determining how to produce it in large quantities from another primary energy source without producing any emissions, and finding a way to store it efficiently.

There are two economically viable mechanisms for extracting hydrogen: water electrolysis and fuel reforming. The former uses electricity to separate the hydrogen and oxygen molecules from water, and will enable citizens to produce it in their homes. The latter employs a reformer to separate the hydrogen molecules contained in the fuel. In order to render the hydrogen emission-free, the method used must not involve indirect emission of carbon dioxide or other greenhouse gases. Therefore, the electricity or fuel used cannot come from fossil derivatives, but rather from clean and renewable sources of energy. The electricity used today comes primarily from coal or natural gas plants; and the most commonly used fuels for obtaining hydrogen are gasoline and natural gas. But the inclusion of their environmental cost in the energy will bring about a shift toward generating electricity from solar energy and the production of hydrogen from biofuels or from solar power itself.

Hydrogen storage is no trivial matter. Although it is difficult to store due to its low volumetric energy density, almost 3,000 times lower than that of gasoline, there are three ways to make hydrogen denser and therefore more suitable for storage: compression, liquefaction, or by combining it with other elements. Each one of these has advantages and disadvantages, and none is currently efficient enough to stand out above the rest. Therefore, the most widely used option today is creating hydrogen in a distributed manner precisely when it is needed; for example, through the use of a reformer to process bioethanol in order to produce gas. These types of approaches are being studied for use in hybrid vehicles.

The transition from the present economic model, based on fossil energies, toward an energy New Deal, based on renewable energies, is vital in building a sustainable future. Given the economic interests tied to fossil energies, reaching the point where the sun and hydrogen meet 80 percent of our energy needs will not be an easy path to follow. We must embrace our knowledge of the advantages of renewable energies, confident in our belief that we are moving in the right direction, and continue to dedicate resources to their development. Our future generations will no doubt appreciate it.

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^[1] The New Deal refers to the package of economic programs initiated between 1933 and 1938 by U.S. president Franklin Delano Roosevelt to aggressively deal with the causes of the major economic crisis of 1929 and thereby promote recovery from the Great Depression in which the country was submerged.
^[2] In economics, an externality is an impact (positive or negative) on any party that is not directly involved in a given economic transaction. Externalities occur when a decision made generates costs or benefits for third parties that are not directly involved in the transaction.
^[3] According to the Stern Review, the total economic cost of climate change (caused by greenhouse gas emissions) exceeds one percent of global gross domestic product per annum. A significant portion of this cost is attributed to emissions derived from the use of fossil energies
^[4] In this context, an energy vector is to be understood as a means of transmitting energy from primary so