Title: Alternative Energy
Course: 2016FA-MCO-115-401 > Section: Module 2: Energy

Alternative Energy

The term alternative energy is generally used when describing a source of energy that does not rely on fossil fuels. Labeling energy sources that are non-fossil fuels as alternative has in recent years become less favorable for some sources. As an energy source becomes increasingly mainstream, the supporters of that source tend to focus less on the fact that it is an alternative and more on the fact that is a valid source for energy supply.

Different types of alternative energy include green and renewable energy like:

- Biofuel Energy
- Geothermal Energy
- Hydropower
- Solar Power
- Wind Energy

Biofuel is a term that describes a fuel that comes from biomass. There are solid, liquid, and gaseous biofuels. Biomass refers to biological matter used as a source of energy. Biomass often refers to plant matter. It can be burned for heat or converted to biofuel.  In general biomass can be converted to other forms of usable energy. Examples of biofuel include ethanol and methane gas. Ethanol is often made from corn in the United States. Landfills make methane gas, it is a byproduct of decomposing garbage. This gas can be used as an energy source [2].

Geothermal energy is the heat energy that comes from the Earth [3]. Hot springs and geysers are naturally occurring sources of geothermal energy. Enhanced geothermal systems (also called EGS) are systems where water is forcefully injected into wells to be heated and then is pumped back out. A geothermal heat pump system can provide central heating and air by using the Earth as a source of heat or as a way to cool. Underground temperatures remain fairly constant and are generally cooler than the outside temperature in the summer and warmer than the outside temperature during winter [4].

Hydropower is a method of harnessing the energy in water and using it to create electricity. The electricity created from the energy in water is called hydroelectricity. There are many forms of water energy to use. Water from the ocean can be used and in some case the power of the tides is utilized. Rivers can be used to glean this energy. Hydrokinetic energy is used to describe energy that comes from moving water [5]. Often times a dam is used as part of the hydropower process. A dam is a structure designed to hold back water. “Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees (also known as dikes) are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are often used in conjunction with dams to generate electricity” [6]. Dams have their own sector in the sixteen Critical Infrastructure Sectors identified by the Department of Homeland Security. (If your instructor chose to use the complete version of this course, dams will be covered in a later subunit.)

Solar power is power or heat that is collected from the Sun and harnessed to create heat or electricity. Sometimes solar is utilized as a method for heating water. This water can be used for bathing and laundry or even to supply warm water to swimming pools (in place of electrical hot water heaters). Solar heated water can also be used as a source of heat for homes or businesses [7]. Solar energy is also harnessed for the sole purpose of creating electricity; this process is achieved by photovoltaic conversion. The word Photovoltaics comes from the Greek word photo meaning light and the word volt meaning electricity. Photovoltaics were created to mimic the photosynthesis process that plants use to create energy using the energy from the Sun. Sometimes photovoltaics is shortened to PV. Photovoltaics create direct current electricity, the most popular forms of photovoltaics use solar panels that contain solar cells. The DC electricity can then be converted to AC with an inverter. PV systems can be utilized on a small scale for things like calculators, slightly larger applications like portable traffic warning signs, and for powering water pumps for farming [8]. Solar panels are used all around the world atop houses and businesses to reduce the power bills of their owners.

As the United States more fully implements the smart grid[i], it will become easier for customers to collect the Sun’s energy and to sell extra energy to their utility company. Work is being done to overcome the limitations that are natural to solar energy. Cloudy days and night skies cause challenges to using solar power alone. The addition of storage capability to the country’s smart grid would help offset these challenges. The use of solar in combination with other renewable energy sources is also used and will continue to grow as a method for overcoming its challenges.

Solar power is a bit different than other power sources since without solar power geothermal power, tidal hydropower, and wind energy would not be possible. In fact, life on Earth is fully dependent on our sun.

Wind energy or wind power are both used to describe the harnessing of the wind to generate electricity or some type of mechanical power. To create electricity, wind is collected through the use of wind turbines. Wind turbines capture the wind’s energy allowing us to make use of it. The turbines then power generators that supply the electricity. Wind energy can be collected in wholesale generation power plants, “where power is sent to consumers via transmission lines and substations” [9]. It can also be collected and utilized as distributed wind power, which is near where it is collected or on the same site [9]. Mechanical power, sometimes found on a smaller scale, can be used to make pumps, grinders, and other mechanical items work [10].

Advantages of wind energy include that in much of the United States wind energy is readily available. There are locations available with average wind speeds conducive to power production. (The greater the speed of the wind, the more electricity or mechanical power is produced.) There is no pollution caused from wind power nor does the process require any fossil fuels to work. However, a disadvantage is that wind is not constant. The variations in wind sometimes cause long lapses in which no wind power can be used. Unlike water, which can be redirected and stored for later use, wind can’t be saved for days that are still and have no wind [10].