​Unit 2: Renewable Energy Use in Your Life

Section A: Benefits of and Barriers to Renewable Energy


Benefits: Wind power is a non-polluting, clean energy source that is widely available with no fuel costs. Each year the electricity generated by the wind in California avoids the production of 16 million pounds of air pollutants and 2.7 billion pounds of greenhouse gases. These wind farms also save the equivalent of 4.8 million barrels of oil each year. Turbines also have low operating and maintenance costs. Wind energy is one of the lowest-priced renewable energy technologies available today, costing between 4 and 6 cents per kilowatt-hour. Wind turbines can be sited on farms and ranches, which allow multiple use of the land (crops, livestock, and wind). Wind TurbineMany property owners can obtain funds from utility companies if they grant access to their lands for wind turbines. There are no harmful fluids involved in the production of wind energy.

Barriers: Wind is intermittent and may not produce power at all times. Home-sized wind systems should be paired with another energy source to provide consistent power. This could be another renewable energy system such as a photovoltaic system, a backup generator, or the traditional electric grid. These components increase the total cost of a wind energy system. Some people are concerned about wind turbines killing birds and feel that turbines should not be used to generate electricity. However, compared to the amount of wildlife deaths caused by acid rain, air pollution, power lines, and other fossil fuel related deaths as well as cars, cats, and window strikes, wind turbine deaths amount to a very small percentage. Siting wind turbines away from migratory routes will decrease bird encounters. Some also feel that wind turbines are loud and dangerous, but due to modern technology and many years of experimentation, wind turbines emit only a small wisping sound and do not cause any hazards. Television reception may be slightly affected if homes are located very near turbines.

Click here to see a summary of Wind-Wildlife Interactions 

Solar Electricity

Benefits: Solar power is a non-polluting, clean energy source that is widely available without any fuel costs. In many remote places where there are no electrical lines, solar power can be used instead. Solar systems are mobile and are virtually maintenance free with only annual cleaning necessary. Solar systems are also reliable and quiet, and can be installed quickly and easily. Photovoltaic systems can be constructed modularly so people can start with two panels and increase the size of the system as they need to, or can afford to.Solar Collector

Barriers: Solar energy isn't produced at night and can also be unreliable due to cloudy weather, making it necessary to store the produced electricity or use backup generators. The number of usable sun hours for each site varies depending on latitude, cloud cover, and other obstacles. This means that photovoltaic systems are not a cost-effective option for all locations. Large-scale solar electric systems need large amounts of land to collect solar energy, which can cause conflict if the land is in an environmentally sensitive area or is needed for other purposes. One solution is to locate large-scale solar electric systems in deserts or marginal lands. Another idea is to place solar cells on existing rooftops, over parking lots, in yards, and along highways, and then connect the systems to an electric utility's power-line system. As the use of solar electric systems increases, laws may be needed to protect people's right to access the sun.


Benefits: Hydropower is a non-polluting, clean energy source that is widely available with no fuel costs and low operating and maintenance costs. Hydroelectric power plants last two to ten times longer than coal and nuclear plants. Impoundments that are created by damming rivers and streams produce bodies of water that create recreational opportunities as well as wildlife habitat. The ability to store water may also be beneficial in times of drought in conjunction with controlling downstream flooding and proving water for crop irrigation.Hydroelectric Dam

Barriers: Building dams may alter the ecosystem of the river or stream by blocking fish migration routes and negatively impacting other wildlife. Hydropower plants can also impact water quality by causing low dissolved oxygen in water which is harmful to aquatic and riparian (shoreline) habitats. In times of drought, the river downstream of the dam may not be sufficient enough to sustain life. This may also have adverse effects on cities downstream that rely on the river for drinking water and food. Another negative effect of hydropower is the loss of wildlife habitat as well as cultural and historical sites which may become flooded and lost beneath the surface of the reservoir water when the river is dammed. Hydropower plants also have a limited life span due to siltation where sediment builds up on one side of the dam which prevents the plant from working at full capacity.


Benefits: Geothermal energy is a non-polluting, clean energy source that is widely available and free. Even in cold climates, everyone has access to the stable 48-55 degree temperatures below the surface of the ground. This energy can be used for heating and cooling for year round comfort. These systems are quiet during operation and highly efficient. Geothermal systems have low maintenance costs because all parts of the system are either inside a building or underground, not being exposed to the elements. Geothermal systems are flexible and can be used in a wide range of building or remodeling projects and have a low environmental impact. Also, the average home built in Wisconsin has sufficient yard space to accommodate the pipes needed for a geothermal system.

Barriers: Secondary or backup heat sources are required in cooler climates making geothermal not as feasible in some areas as others. There are some concerns about indoor air quality. There are also concerns regarding the release of hydrogen sulfide from the ground when geothermal drilling takes place for deep energy sources. When drilling occurs to obtain the energy from the earth's steam or water, reinjection of these materials must occur without polluting the groundwater. Also, depletion of geysers and surface hot springs may occur if more steam or water is removed from the earth than is produced which may hinder ecosystems that depend on the unique characteristics of these for survival. Subterraneous extraction of heat and fluid can also cause land subsidence, much like the extraction of groundwater. Certain natural substances, such as arsenic, boron, and mercury, are sometimes present in the water released from geothermal cooling towers. Additionally, carbon dioxide, a greenhouse gas, is released from geothermal cooling towers. However, this release of carbon dioxide is less than one-tenth the amount that would be released from a fossil fuel electrical generation facility of similar capacity. There are disposal issues with the fluid inside the tubes which collect or discard the heat which may consist of toxins.


Benefits: Using biomass fuels provides a number of benefits for society and the environment. Biomass is a renewable resource when harvested sustainably and can easily be stored. Biomass fuels can be produced from organic materials found throughout the world. Since most biomass is grown in rural areas, biomass fuel production can benefit rural economies by providing jobs. Using ethanol and methanol fuels in motor vehicles helps conserve oil resources. Agricultural waste and other organic materials now have a use and can be disposed of (burned) while creating energy. Unburned biogas and methane gas are greater contributors to global warming than carbon dioxide. Burning these gases as fuel prevents them from being released into the atmosphere. Burning waste wood for fuel eliminates having to put it in landfills.

Barriers: The burning of agricultural residues and other organic materials produces air pollution such as smoke, carbon monoxide, and polycyclic aromatic hydrocarbons that may cause bronchitis, emphysema, and cancer. Indoor air pollution may occur due to improper burning or leaks in pipes and chimneys. Outdoor air pollution may arise when large number of residents burn wood. However, high-efficiency woodstoves can reduce air pollution problems. In the United States, new wood stoves are required to emit 70 percent fewer Biomassparticulates than those sold before 1990. Burning wood also releases carbon dioxide and nitrogen oxide; however, these emissions from burning biomass fuels are generally lower than those from burning coal. Emissions from burning biogas and biomass-produced methane are comparable to emissions from burning natural gas. Burning biomass fuels releases carbon dioxide, a suspected cause of global warming. However, the plants used to produce biomass consume carbon dioxide so replanting trees is important to absorb the carbon dioxide. The cultivation of species (trees, crops, etc.) may lead to widespread monocultures (one species only) which may replace healthy, diverse forests and other ecosystems. Monocultures are also susceptible to disease and other factors which may wipe out that population. Biomass crops only grow part of the year and may fail, limiting supplies of biomass fuels. Harvesting large areas (deforestation or clear-cutting) to produce biomass fuels can harm wildlife habitats and may contribute to soil erosion. The loss of topsoil due to erosion will make tree replanting more difficult. Burning agricultural wastes may deprive the soil of nutrients; burning municipal solid waste may produce toxic emissions. Using crops to produce alcohol fuels competes with their use as food. Large amounts of energy are often needed to harvest crops and transport them long distances. This may limit the advantages of using certain types of biomass as energy resources, especially by large power plants. Total energy produced is usually less than the energy used in production if the energy to grow, harvest, produce, and transport with current farming methods is included (Net negative energy).


Go back to Unit 1: Section E


Continue on to Section B: Comparing Renewable and Non-renewable Energy Costs