**Renewable Energy Use and Energy Efficiency – A Critical Tool for Sustainable Development**

Pius Fatona

*School of Environmental Health Science, Ogun State College Of Health Technology, Nigeria* 

### **1. Introduction**

48 Sustainable Growth and Applications in Renewable Energy Sources

Sax, U., Weisbecker, A., Falkner, J., Viezens, F., Mohammed, Y., Hartung, M., Bart, J.,

Tragedy of the commons, http://en.wikipedia.org/ wiki/Tragedy\_of\_the\_commons

*und Telemedizin*, Vol. 4, pp. 61-63

KG, Darmstadt, ISBN 978-393-7948-06-5, pp. 47-51

Patientenakte der Zukunft," *E-HEALTH-COM - Magazin für Gesundheitstelematik* 

Krefting, D., Knoch, T. A. & Semler S. C. (2008). Auf dem Weg zur individualisierten Medizin - Grid-basierte Services für die EPA der Zukunft. In A. Jäckel (ed.), *J Telemedizinführer Deutschland 2008.* Deutsches Medizinforum, Minerva

> Energy efficiency and renewable energy are the "twin pillars" of a sustainable energy policy. Both strategies must be developed concurrently in order to stabilize and reduce carbon dioxide emission (American Council for an Energy-Efficient Economy, 2007). Efficient energy use is essential to slowing the energy demand growth so that rising clean energy supplies can make deep cuts in fossil fuel use. If energy use grows too rapidly, renewable energy development will chase a receding target. Likewise, unless clean energy supplies come online rapidly, slowing demand growth will only begin to reduce total carbon emissions; a reduction in the carbon content of energy sources is also needed. A sustainable energy economy thus requires major commitments to both efficiency and renewable (American Council for an Energy-Efficient Economy, 2007).

Estimates of the world energy use indicate that the demand for energy, by the middle of the 21st Century, may significantly exceed the energy supplied by conventional sources. The shortfall in energy becomes larger after the depletion of fossil fuels, about 100 years in the future. Source: http://www.plasma.inpe.br

Renewable Energy Use and Energy Efficiency – A Critical Tool for Sustainable Development 51

3. They are clean and pollution-free and therefore are sustainable natural form of energy. 4. They can be cheaply and continuously harvested and therefore sustainable source of

Unlike the nuclear and fossil fuel plants which belong to big companies, governments, or state around enterprises, renewable energy can be set up in small units and is therefore suitable for community management and ownership. In this way, value from renewable

Transition from fossil fuels to renewable energy will not result in net job losses or cause harm to the economy. Renewal energy technologies (RETs) are labour intensive, and can produce more jobs than fossil fuel or nuclear industries. When RETs are properly integrated into national development plans and implemented, they can substantially reduce greenhouse gas emissions and simultaneously increase employment (Pearce et al, 1989). Moreover, it will also enhance energy security by reducing reliance on oil, preserve the competitiveness of energy, lead to savings for consumers and provide transitional assistance to workers in negatively affected industries and communities. With the right approach the interest of working families and the environment can come together (Pearce et al, 1989).

Energy efficiency means improvement in practice and products that reduce the energy necessary to provide services like lightning, cooling, heating, manufacturing, cooking, transport, entertainment etc. Energy efficiency products essentially help to do more work with less energy. Thus, the efficiency of an appliance or technology is determined by the amount of energy needed to provide the energy service. For instance, to light a room with an incandescent light bulb of 60w for one hour requires 60w/h. A compact florescent light bulb would provide the same or better lighting at 11w and only use 11w/h. This means that 49w (82% of energy) is saved for each hour the light is turned

Making homes, vehicles, and businesses more energy efficient is seen as a largely untapped solution to addressing the problems of pollution, global warming, energy security, and fossil fuel depletion. Many of these ideas have been discussed for years, since the 1973 oil crisis brought energy issues to the forefront. In the late 1970s, physicist Amory Lovins popularized the notion of a "soft energy path", with a strong focus on energy efficiency. Among other things, Lovins popularized the notion of negawatts—the idea of meeting energy needs by increasing efficiency instead of increasing energy

Lovins viewed the energy problem not one of an insufficient supply of oil and other conventional energy sources, but rather as one of inefficient energy use, coupled with lack of development of renewable energy sources. Lovins argued that conventional energy production was both energy intensive and a source of substantial pollution. With his reformulation of the energy problem, "environmentalists criticized plans for large-scale

The "soft energy path" assumes that energy is but a means to social ends, and is not an end in itself. Soft energy paths involve efficient use of energy, diversity of energy production methods (matched in scale and quality to end uses), and special reliance on co-generation and "soft energy technologies" such as solar energy, wind energy, bio-fuels, geothermal

energy developments, especially those relying heavily on nuclear power".

energy, wave power, tidal power, etc (Nash, 1979).

energy.

on.

energy projects can be kept in the community.

**2. What is energy efficiency?** 

production (Krech, 2004).

Renewable energy is energy which comes from natural resource such as sunlight, winds, plants growth, rain, tides and geothermal heat which are naturally replenished.

The first law of thermodynamic says that the total amount of energy on our planet remains constant. The second law states that as forms of energy are expended they become less easily available. That is entropy: the slow winding down of available energy (Jacobson, 2009).

 First law of thermodynamics: *A change in the internal energy of a closed thermodynamic system is equal to the difference between the heat supplied to the system and the amount of work done by the system on its surroundings.*

The first law of thermodynamics asserts the existence of a state variable for a system, the internal energy, and tells how it changes in thermodynamic processes. The law allows a given internal energy of a system to be reached by any combination of heat and work. It is important that internal energy is a variable of state of the system whereas heat and work change the state of the system.

The first law observes that the internal energy obeys the principle of conservation of energy, which states that energy can be transformed (changed from one form to another), but cannot be created or destroyed.

 Second law of thermodynamics: *Heat cannot spontaneously flow from a colder location to a hotter location.*

The second law of thermodynamics is an expression of the universal principle of decay observable in nature. The second law is an observation of the fact that over time, differences in temperature, pressure, and chemical potential tend to even out in a physical system that is isolated from the outside world. Entropy is a measure of how much this process has progressed. The entropy of an isolated system which is not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.

When coal, gas or oil is burnt, it rapidly converts a relatively easily available and concentrated source of energy into a much less available form: dispersed exhaust gases.

A high concentrated energy source, built up over millions of years quickly gone up in smoke. So, burning fossil fuels is high-entropy way of using energy.

Using renewable energy however merely taps into a natural flow of energy, sunlight, moving water, wind, biological or geothermal process. These are part of natural cycles of highs and lows. Their energy is truly renewable as it remains available to the same degree and is not depleted any more than it otherwise would be by using it.

Renewable energies include wind, ocean, wave and tides, solar, biomass, rivers, geothermal (heat of the earth) etc. They are renewable because they are regularly replenished by natural processes and are therefore in endless supply (Fatona, 2009; Jacobson, 2009). They also can operate without polluting the environment. Technologies have been developed to harness these energies and such technologies are called renewable energy technologies (RET) or sometime also called "Clean technologies" or "Green energy" (Pearce et al, 1989). Because renewable energy are constantly being replenished from natural sources, they have security of supply, unlike fossil fuels, which are negotiated on the international market and subject to international competition, sometimes may even resulting in wars and shortages. They have important advantages which could be stated as follows:-


Unlike the nuclear and fossil fuel plants which belong to big companies, governments, or state around enterprises, renewable energy can be set up in small units and is therefore suitable for community management and ownership. In this way, value from renewable energy projects can be kept in the community.

Transition from fossil fuels to renewable energy will not result in net job losses or cause harm to the economy. Renewal energy technologies (RETs) are labour intensive, and can produce more jobs than fossil fuel or nuclear industries. When RETs are properly integrated into national development plans and implemented, they can substantially reduce greenhouse gas emissions and simultaneously increase employment (Pearce et al, 1989). Moreover, it will also enhance energy security by reducing reliance on oil, preserve the competitiveness of energy, lead to savings for consumers and provide transitional assistance to workers in negatively affected industries and communities. With the right approach the interest of working families and the environment can come together (Pearce et al, 1989).
