Energy, in physics, the capacity for doing work. It may exist in potential, kinetic, thermal, electrical, chemical, nuclear, or other various forms. There are, moreover, heat and work—i.e., energy in the process of transfer from one body to another. After it has been transferred, energy is always designated according to its nature. Hence, heat transferred may become thermal energy, while work done may manifest itself in the form of mechanical energy.
There are many different forms of energy, such as light energy, heat energy, mechanical energy, gravitational energy, electrical energy, sound energy, chemical energy, nuclear or atomic energy. The two major forms of energy are Kinetic Energy and Potential Energy.
Kinetic energy is the energy in moving objects, such as wind energy where the molecules of gas in the air move, giving them kinetic energy. Potential energy is any form of energy that has stored potential that can be put to future use, for instance water stored in a dam for hydroelectricity generation, or solar energy that is stored in batteries.
The First Law of Thermodynamics states that energy cannot be created or destroyed. It can, however, be transferred from one location to another and converted to and from other forms of energy.
Alternative energy is any energy that is produced from sources other than fossil fuel. Renewable energy is any source of energy that doesn’t consume the finite resources of the Earth and can be easily and quickly replenished.
At this time, only a small quantity of the world’s energy comes from alternative and renewable energy sources. These exist in many forms including Solar Thermal, Photovoltaics, Wind, Hydro, Tidal and Bioenergy, which includes Biomass, Biogas and Biofuels. The sun’s energy is the ultimate source of these energies.
Our standard of living has significantly improved as the result of increased energy use over the last hundred or so years. We need energy for just about everything in our homes. In fact, energy is the most important aspect of modern living and convenience. We couldn’t perform most of our daily tasks without energy.
The energy we use in our daily lives falls into three broad categories—food that gives us energy, energy that makes a house a home, and the fuel we put in our vehicles.
Residential energy is the most basic use of energy. This includes watching your favorite television show washing clothes, taking a hot shower.
Types of Renewable Resources.
Natural resources are a form of equity, and they are known as natural capital. Biofuel, or energy made from renewable organic products, has gained prevalence in recent years as an alternative energy source to nonrenewable resources such as coal, oil, and natural gas. Although prices are still higher for biofuel, some experts project that increasing scarcity and the forces of supply and demand will result in higher prices for fossil fuels, which will make the price of biofuel more competitive.
Types of biofuel include biodiesel, an alternative to oil, and green diesel, which is made from algae and other plants. Other renewable resources include oxygen and solar energy. Wind and water are also used to create renewable energy. For example, windmills harness the wind’s natural power and turn it into energy.
The problem with using renewable resources on a large scale is that they are costly and, in most cases, more research is needed for their use to be cost-effective.
Adopting sustainable energy is often referred to as “going green” due to the positive impact on the environment. Energy sources such as fossil fuels damage the environment when burned and contribute to global warming.
Many nations count on coal, oil and natural gas to supply most of their energy needs, but reliance on fossil fuels presents a big problem. Fossil fuels are a finite resource. Eventually, the world will run out of fossil fuels, or it will become too expensive to retrieve those that remain. Fossil fuels also cause air, water and soil pollution, and produce greenhouse gases that contribute to global warming.
Renewable energy resources offer cleaner alternatives to fossil fuels. They are not completely problem-free, but they produce much less pollution and fewer greenhouse gases, and by definition, will not run out.
Here are our main sources of renewable energy:
is our most powerful source of energy. Sunlight, or solar energy, can be used for heating, lighting and cooling homes and other buildings, generating electricity, water heating, and a variety of industrial processes. The technology used to harvest the sun’s energy is constantly evolving, including water-heating rooftop pipes, photo-voltaic cells, and mirror arrays.
is the movement of air that occurs when warm air rises and cooler air rushes in to replace it. The energy of the wind has been used for centuries to sail ships and drive windmills that grind grain. Today, wind energy is captured by wind turbines and used to generate electricity.
_Water flowing downstream :
is a powerful force. Water is a renewable resource, constantly recharged by the global cycle of evaporation and precipitation. The heat of the sun causes water in lakes and oceans to evaporate and form clouds. The water then falls back to Earth as rain or snow and drains into rivers and streams that flow back to the ocean. Flowing water can be used to power water wheels that drive mechanical processes. And captured by turbines and generators, like those housed at many dams around the world, the energy of flowing water can be used to generate electricity. Tiny turbines can even be used to power single homes.
Wood is still the most common source of biomass energy, but other sources of biomass energy include food crops, grasses and other plants, agricultural and forestry waste and residue, organic components from municipal and industrial wastes, even methane gas harvested from community landfills. Biomass can be used to produce electricity and as fuel for transportation, or to manufacture products that would otherwise require the use of non-renewable fossil fuels.
Hydrogen has tremendous potential as a fuel and energy source. Hydrogen is the most common element on Earth—for example, water is two-thirds hydrogen—but in nature, it is always found in combination with other elements. Once separated from other elements, hydrogen can be used to power vehicles, replace natural gas for heating and cooking, and generate electricity.
The heat inside the Earth produces steam and hot water that can be used to power generators and produce electricity, or for other applications such as home heating and power generation for industry. Geothermal energy can be drawn from deep underground reservoirs by drilling, or from other geothermal reservoirs closer to the surface.
_Ocean Energy :
The ocean provides several forms of renewable energy, and each one is driven by different forces. Energy from ocean waves and tides can be harnessed to generate electricity, and ocean thermal energy—from the heat stored in seawater—can also be converted to electricity.
Non-renewable energy sources.
Coal is a black or brown rock that is burned to produce energy and extracted from the ground.
Oil is a liquid fossil fuel, also called petroleum, or crude oil. It is trapped in rock formations under the surface of the earth, and it is extracted from the ground with the help of special drilling machines.
Natural gas is a fossil fuel found in the ground, trapped in tanks, and it consists mainly of methane gas, and it is used in heating and cooking.
Len Calderone “energy powers our lives”، altenergymag.com
CAROLINE BANTON “Renewable Resource”، www.investopedia.com
Larry West “Top Renewable Energy Sources”، www.thoughtco.com
non-renewable energy ، www.nationalgeographic.org