Reliable Sources ofRenewable Energy

ALEXANDERCHRISTODOULAKIS

There are many types of renewable energy, most of which dependon sunlight. Wind and hydroelectric power are the direct results of

differential heating of the Earth’s surface which leads to airmoving about (wind) and precipitation forming as the air is lifted.

Solar energy is the direct conversion of sunlight using panels orcollectors. Biomass energy is stored sunlight contained in plants.

Other renewable energies that do not depend on sunlight aregeothermal energy, which is a result of radioactive decay in the

crust combined with the original heat of accreting the Earth, andtidal energy, which is a conversion of gravitational energy.

Solar

This type of energy relies on the nuclear fusion power from thecore of the Sun. This energy can be collected and converted ina few different ways. The range is from solar water heating with

solar collectors or attic cooling with solar attic fans fordomestic use to the complex technologies of direct conversion

of sunlight to electrical energy using mirrors and boilers orphotovoltaic cells.

WindPower

The movement of theatmosphere is driven by

differences in temperature atthe Earth’s surface due to

varying temperatures of theEarth’s surface when lit by

sunlight. Wind energy can beused to pump water orgenerate electricity butrequires extensive areal

coverage to producesignificant amounts of

energy.

Hydroelectric Energy

This type uses thegravitational potential of

elevated water that was liftedfrom the oceans by sunlight.

Most of the availablelocations for hydroelectric

dams are already used in thedeveloped world.

BiomassEnergy in this type is commonly used throughout the world.Unfortunately, the most popular are the burning of trees forcooking and warmth. This process releases copious amountsof carbon dioxide gasses into the atmosphere and is a major

contributor to unhealthy air in many areas. Some of themore modern forms of biomass energy are methane

generation and production of alcohol for automobile fueland fuelling electric power plants.

Hydrogen andFuel Cells

Hydrogen can be burned as a fuel, typically in avehicle, with only water as the combustion

product. This clean burning fuel can mean asignificant reduction of pollution in cities. Orthe hydrogen can be used in fuel cells, whichare like batteries, to power an electric motor.

Due to the need for energy to produce theinitial hydrogen gas, the result is the relocationof pollution from the cities to the power plants.

There are several promising methods toproduce hydrogen, such as solar power, that

may alter this picture drastically.ALEXANDERCHRISTODOULAKIS