Climate Change

In order to address this problem, Wild South has formed a Climate Change Analysis team to assess the regional impacts of climate change and facilitate communication with the public and land managers. By bridging the information gap between science, policy and those affected, we can begin taking the necessary steps to secure a better future.

Hydroelectric

Similar to wind power and biomass, hydroelectric power begins with the sun, which drives the water cycle. Heat from the sun causes water to evaporate, and this water returns to the ground as precipitation. As the water flows towards the ocean through lakes and rivers, its kinetic energy can be captured in dams and converted into electrical power. Dams typically create a reservoir of stored water and pass it through a turbine to generate power as needed. As the most common form of renewable energy, hydropower supplies around 20% of the world’s electricity and around 34% of renewable energy in the United States.

Pros:

Operating a hydroelectric facility generates minimal carbon dioxide emissions.

Reservoirs allow energy be easily stored and used as needed.

Hydroelectric facilities are relatively inexpensive to operate.

Many rivers in the U.S. are suitable for hydropower, especially in the West.

As long as rivers are flowing, hydroelectric power will not run out.

Cons:

Reservoirs for hydroelectric power often require large amounts of flooding, destroying riparian zones and other ecosystems as well as human communities.

Dams cause sediment build-ups in reservoirs as water passes through but leaves dirt and clay behind.

When water goes through dams, it releases methane, a greenhouse gas formed as organic matter decomposes in reservoirs. By some estimates, these emissions could contribute more to climate change than comparable burning of fossil fuels.

Hydroelectric plants require a high initial investment, although usually not as high as other forms of renewable energy.

Dams depend on water flow, so they generate less energy in times of drought.

Most of the potential hydropower in the U.S. is already being used, leaving little room for growth.

Other sources of information on biomass:

U.S. Department of Energy - Hydropower Basics

Union of Concerned Scientists - How Hydroelectric Energy Works

National Geographic - Hydropower

National Atlas - Hydropower

Resource Maps:

Idaho National Laboratory - State Resource Assessment

National Atlas - Hydropower Map

Biomass

Biomass is energy derived from living matter, and it is another source of renewable energy that starts with the sun. Sunlight fuels photosynthesis, which is the basis for the rest of the food web. However, biomass is different from most renewable energy sources in that it involves the combustion of fuel. It is considered renewable because it uses fuels like plant matter, animal waste, and algae, which regenerate relatively quickly. Biomass can supply both electrical power (known as biopower) and motor vehicle fuel (known as biofuel). It is the largest source of renewable energy in the US, comprising 53% of the country’s renewable energy consumption.

Pros:

Although combustion of biomass releases greenhouse gases, some these would be released anyway during decomposition or will be reabsorbed in subsequent regrowth. As a result, many of the emissions cancel out.

Biomass resources are not in danger of running out as long as they are managed sustainably.

Many sources of biomass already exist and others can be obtained without much expense, so fuel costs are fairly low. Also, biomass plants involve technology that already exists at a reasonable cost. This makes biomass relatively inexpensive overall, especially compared to other renewables.

A large amount of biomass in the form of waste wood and crop residue is readily available.

Biomass is a reliable resource. It allows more power to be generated when demand is higher and less to be generated when demand is lower.

Biomass can directly replace fossil fuels in many power plants and cars.

Cons:

Expanding the market for woody biomass creates a financial incentive for cutting whole trees, which gravely threatens forest ecosystems.

The extraction and combustion of whole trees can result in more immediate emissions than burning fossil fuels.

When grown instead of food crops, biofuels diminish food supplies, leading to increased food prices worldwide.

The process of growing some of the most common biofuel crops is highly inefficient. The energy input, usually in the form of fossil fuels, often exceeds the energy output of the final product.

Some biomass plants release particulate matter that can cause respiratory disease and other health effects in surrounding communities. These facilities are often too small to be regulated by the Clean Air Act.

Cellulosic and algal biofuels can be grown sustainably without interrupting food production, but these newer technologies are not yet practical on a large commercial scale.

Click here to learn how biomass affects forests

Other sources of information on biomass:

National Renewable Energy Laboratory - Biomass Energy Basics

Southern Alliance for Clean Energy - Learn About Biopower

Southern Alliance for Clean Energy - Learn About Biofuels

Union of Concerned Scientists - How Biomass Energy Works

Resource Maps:

National Renewable Energy Laboratory - Biomass Maps

Geothermal

Three to five miles below the earth’s surface, temperatures are often hot enough to boil water (over 212ºF). This energy, called geothermal, can be harnessed for electrical power by drilling holes to deep into the ground and pumping water into them. The water heats up and rises, creating steam that powers turbines. Geothermal energy can be obtained from natural geysers instead of drilling, but this is less common on a commercial scale.

Pros:

Geothermal plants release practically no emissions once they are in place.

After the initial investment, geothermal plants are very inexpensive to operate.

Geothermal plants do not take up much space above ground, so they have few aesthetic impacts.

Geothermal energy is highly reliable. It can be generated year-round for 24 hours a day.

Geothermal resources are abundant on the West Coast.

Geothermal energy is the world’s longest lasting energy source. It will be around for billions of years, potentially outlasting the sun.

Cons:

As with every energy source mentioned so far, building a geothermal plant requires a high initial investment.

Strong geothermal resources are not common in the eastern part of the U.S.

Drilling near fault lines has been known to cause earthquakes.

Other sources of information on geothermal energy:

U.S. Department of Energy - Geothermal Basics

Union of Concerned Scientists - How Geothermal Energy Works

Idaho National Laboratory - What is Geothermal Energy?

Resource Maps:

National Renewable Energy Laboratory - Geothermal Maps

U.S. Department of Energy - Geothermal Resource Maps

Solar

There are two ways to generate energy directly from the sun’s rays. Solar photovoltaic involves silicon cells that chemically convert sunlight into electricity, and concentrated solar power uses sunlight to heat water into steam, which powers a turbine. Concentrated solar power is used almost exclusively for utility-scale generation, while solar photovoltaic is used mostly for powering individual buildings, although solar photovlataic can be used for utility-scale generation as well.

Pros:

Similar to wind energy, solar power does not produce greenhouse gases or other pollution (aside from small amounts during manufacturing, transportation, and installation).

Photovoltaic panels can be installed on rooftops or open areas, where they provide power directly to the source of demand.

Solar power will never run out as long as the sun is shining.

Solar power is very cheap to generate once the system is in place.

Cons:

Photovoltaic panels and concentrating mirrors both require a very high initial investment, so solar electricity is one of the most expensive forms of energy overall.

Solar power might be insufficient at times, because it cannot be generated at night or on overcast days, and it cannot be stored easily.

In the United States, the sunlight strong enough for large-scale solar power is mostly in open areas of the Southwest, far from the greatest sources of demand.

Solar arrays take up large amounts of land, which is potentially disturbing to scenic areas and wildlife habitat.

To be effective, solar power requires a lot of water, which is often scarce in places with the best sunlight.

Other sources of information on solar energy:

National Renewable Energy Laboratory - Solar Energy Basics

Southern Alliance for Clean Energy - Learn About Solar

Union of Concerned Scientists - How Solar Energy Works

U.S. Department of Energy - Why PV is Important

N.A.S.A. - How do Photovoltaics Work?

Resource Maps:

National Renewable Energy Laboratory - Solar Maps

Wind

Wind power originates with the sun. When solar radiation heats the atmosphere unevenly, warmer air expands and rises while colder air sinks below it. This creates wind currents that can power electricity-generating turbines. The size of wind turbines varies depending on the scale of electricity being generated. Typically, a small-scale turbine for residential use is 100 to 200 feet high, while a large-scale turbine for utility use is 200 to 400 feet high. Although large turbines are more expensive to build, they are cheaper to operate per unit of energy. In the United States, wind power currently makes up less than 1% of total consumption, but it is one of the fastest growing energy industries in the world.

Pros:

Generating wind energy does not produce greenhouse gases or other pollution. A few emissions result from building, transporting, and installing the turbines but in small amounts compared to other sources of energy.

After the initial investment, wind is one of the cheapest sources of power.

The U.S. has an abundant supply of wind.

Wind farms can often be built on farms and ranches where the turbines will not interfere with other land use.

Cons:

Wind is inconsistent, and the power cannot be stored easily, so it may be insufficient at times of high demand.

Building turbines requires high initial investment, especially offshore.

The strongest winds are often in remote locations, far from where the energy is needed most.

Nearby communities sometimes complain that the blades are noisy and that the turbines disrupt scenic views, hampering tourism.

Wind turbines can disturb wildlife. Birds and bats have been observed to crash into the blades, but windows, power lines, and domestic cats are much greater hazards.

Click here to learn about the wind energy debate in western North Carolina

Other sources of information on wind energy:

U.S. Department of Energy - Wind Energy Basics

Southern Alliance for Clean Energy - Learn About Wind

Union of Concerned Scientists - How Wind Energy Works

The American Wind Energy Association - Wind Web Tutorial

Argonne National Laboratory - Wind Energy Basics

Resource Maps:

National Renewable Energy Laboratory - Wind Maps

U.S. Department of Energy - Wind Maps and Wind Resource Potential Estimates