RENEWABLE RESOURCES

A natural resource qualifies as a renewable resource if it is replenished by natural resources at a rate comparable or faster than its rate of consumption by humans or other users.Solar radiation, tides, winds, nuclear reactors, geothermal and hydroelectricity are perpetual resources that are in no danger of being used in excess of their long-term availability. The term alas has the connotation of sustainability of the handlings of waste products by the natural environment.Nuclear energy is energy in the nucleus (core) of an atom. Atoms are tiny particles that make up every object in the universe. There is enormous energy in the bonds that hold atoms together.

Nuclear energy can be used to make electricity. But first the energy must be released. It can be released from atoms in two ways: nuclear fusion and nuclear fission. In nuclear fusion, energy is released when atoms are combined or fused together to form a larger atom. This is how the sun produces energy. In nuclear fission, atoms are split apart to form smaller atoms, releasing energy. Nuclear power plants use nuclear fission to produce electricity.

The fuel most widely used by nuclear plants for nuclear fission is uranium. Uranium is nonrenewable, though it is a common metal found in rocks all over the world. Nuclear plants use a certain kind of uranium, U-235, as fuel because its atoms are easily split apart. Though uranium is quite common, about 100 times more common than silver, U-235 is relatively rare. Most U.S. uranium is mined, in the Western United States. Once uranium is mined the U-235 must be extracted and processed before it can be used as a fuel.

During nuclear fission, a small particle called a neutron hits the uranium atom and splits it, releasing a great amount of energy as heat and radiation. More neutrons are also released. These neutrons go on to bombard other uranium atoms, and the process repeats itself over and over again. This is called a chain reaction.

Nuclear reactors are basically machines that contain and control chain reactions, while releasing heat at a controlled rate. In electric power plants, the reactors supply the heat to turn water into steam, which drives the turbine-generators. The electricity travels through high voltage transmission lines and low voltage distribution lines to homes, schools, hospitals, factories, office buildings, rail systems and other users.

Compared to electricity generated by burning fossil fuels, nuclear energy is clean. Nuclear power plants produce no air pollution or carbon dioxide but a small amount of emissions result from processing the uranium that is used in nuclear reactors.

Like all industrial processes, nuclear power generation has by-product wastes: spent (used) fuels, other radioactive waste, and heat. Spent fuels and other radioactive wastes are the principal environmental concern for nuclear power. Most nuclear waste is low-level radioactive waste. It consists of ordinary tools, protective clothing, wiping cloths and disposable items that have been contaminated with small amounts of radioactive dust or particles. These materials are subject to special regulation that govern their disposal so they will not come in contact with the outside environment.

Solar power is the energy derived directly from the Sun. It is the most abundant source of energy on Earth. The fastest growing type of alternative energy, increasing at 50 percent a year, is the photovoltaic cell, which converts sunlight directly into energy. The Sun yearly delivers more than 10,000 times the energy that humans currently use.

Solar dishes

Wind power is derived from uneven heating of the Earth's surface from the Sun and the warm core. Most modern wind power is generated in the form of electricity by converting the rotation of turbine blades into electrical current by means of an electrical generator. In windmills (a much older technology) wind energy is used to turn mechanical machinery to do physical work, like crushing grain or pumping water.

Windmills in Burgos, Ilocos Norte

Hydropower energy derived from the movement of water in rivers and oceans (or other energy differentials), can likewise be used to generate electricity using turbines, or can be used mechanically to do useful work. It is a very common resource.

Maria Cristina Falls in Iligan City

Geothermal power directly harnesses the natural flow of heat from the ground. The available energy from natural decay of radioactive elements in the earth's crust and mantle is approximately equal to that of incoming solar energy.

The natural heat within the earth is the motor of the "geothermal energy". In fact, the earth serves as a hot water-boiler. The heat of the earth warms up water (fluids) which is trapped in rock formations thousands of feet (3,000 meter) beneath the earth's surface.

Worldwide, the Philippines rank second to the United States in producing geothermic energy. Leyte is of the island in the Philippines where geothermic power plants were developed. The developments here started in 1977 by the company Philippine National Oil Company (PNOC). Many of the geothermic natural resources are still waiting to be "harnessed for steam."

Leyte is one of the Philippine islands where geothermal energy is produced.

In the Philippines geothermal energy already provides 27% of the country's total electricity production generated in power plants. Geothermal power plants are on the islands Luzon, Negros, Mindanao and Leyte.

Geothermal Plant in Tongonan, Leyte

The production of the electricity by geothermal plants is cheaper than the electricity produced in plants by using natural gas and coal. It is even cheaper than electricity produced by hydro power stations.

Biomass Energy or Bioconversion

It is just composed of organic materials, most of which are waste. Sources include composting materials, wood, municipal and city wastes, bagasse, coconut waste and animal waste

From biomass, one can get the following:

• ethanol (fermenting high carbohydrate biomass sources)
  
• biodiesel/biofuel (from Jethropa sp.)
• fuel oil
  

Alcohol derived from corn, sugar cane, etc. is also a renewable source of energy. Similarly, oils from plants and seeds can be used as a substitute for non-renewable diesel. Methane is also considered as a renewable source of energy.