Energy is a property of objects which can be transferred to other objects or converted into different forms, but cannot be created or destroyed. The ability of a system to perform work is a common description.
In SI units, energy is measured in joules, the energy transferred to an object by the mechanical work of moving it 1 metre against a force of 1 newton.
Energy Development
Energy development is a field of endeavor focused on making available sufficient primary energy sources and secondary energy forms to meet the needs of society. These endeavors encompass those which provide for the production of conventional, alternative and renewable sources of energy, and for the recovery and reuse of energy that would otherwise be wasted. Energy conservation and efficiency measures reduce the impact of energy development, and can have benefits to society with changes in economic cost and with changes in the environmental effects.
Types of Energy
The natural elements of the material world exist in forms that can be converted into usable energy and are resources from which society can obtain energy to produce heat, light, and motion (among the many uses). According to their nature, the power plants can be classified into:
- Primary : They are found in nature: wind, water, solar, wood, coal, oil, nuclear.
- Secondary : Are those obtained from primary energy sources: electricity, gas.
Classified according to the energy reserves of the energy source used and the regeneration capacity with:
- renewable: When the energy source used is freely regenerated in a short period and there are practically limitless reserves; An example is the solar energy that is the source of energy from the sun, or the wind used as an energy resource.
- nonrenewable: They are coming from energy limited sources on Earth in quantity and, therefore, are exhaustible. The non-renewable energy sources include, fossil source like petroleum, natural gas, coal or original mineral/chemical like uranium, shale gas.
Characteristics of Energy
- Energy can be transferred from one object to another.
- Energy comes in many different forms, which can generally be divided into Potential or Kinetic energy.
- Energy can be converted from any one of these forms into any other, and vice versa.
- Energy is never created or destroyed – this is called the First Law of Thermodynamics
- Energy is capacity to do work
Energy Parameters
Energy Elasticity – Energy elasticity is a term used with reference to the energy intensity of Gross Domestic Product. It is “the percentage change in energy consumption to achieve one per cent change in national GDP”.
This term has been used when describing sustainable growth in the developing world, while being aware of the need to maintain the security of energy supply and constrain the emission of additional greenhouse gases. Energy elasticity is a top-line measure, as the commercial energy sources used by the country in question are normally further itemised as fossil, renewable, etc.
For example, India’s national Integrated Energy Policy of 2005 noted current elasticity at 0.80, while planning for 7-8% GDP growth. It expected to be able to reduce this to 0.75 from 2011 and to 0.67 from 2021-22. By 2007, India’s Ambassador was able to inform the United Nations Security Council that its GDP was growing by 8%, with only 3.7% growth in its total primary energy consumption, suggesting it had effectively de-linked energy consumption from economic growth.
China has shown the opposite relationship, as, after 2000, it has consumed proportionately more energy to achieve its high double-digit growth rate. Although there are problems with the quality of the estimates of both GDP and energy consumption, by 2003-4 observers placed Chinese energy elasticity at approximately 1.5. For every one percent increase in GDP, energy demand grew by 1.5 percent. Much of this extra demand has been sourced internationally from fossil fuels, such as coal and petroleum.
Energy Intensity – Energy intensity is a measure of the energy efficiency of a nation’s economy. It is calculated as units of energy per unit of GDP.
- High energy intensities indicate a high price or cost of converting energy into GDP.
- Low energy intensity indicates a lower price or cost of converting energy into GDP.
Energy Intensity as defined here is not to be confused with Energy Use Intensity (EUI), a measure of building energy use per unit area.
