Electricity Usage in the USA

Who Turned Out the Lights?

The United States uses many different energy sources and technologies to generate electricity. The sources and technologies have changed over time and some are used more than others.

The three major categories of energy for electricity generation are fossil fuels (coal, natural gas, and petroleum), nuclear energy, and renewable energy sources. Most electricity is generated with steam turbines using fossil fuels, nuclear, biomass, geothermal, and solar thermal energy. Other major electricity generation technologies include gas turbines, hydro turbines, wind turbines, and solar photovoltaics.

Who Is Paying the Power Bill?

The United States uses many different energy sources and technologies to generate electricity. The sources and technologies have changed over time and some are used more than others.

The three major categories of energy for electricity generation are fossil fuels (coal, natural gas, and petroleum), nuclear energy, and renewable energy sources. Most electricity is generated with steam turbines using fossil fuels, nuclear, biomass, geothermal, and solar thermal energy. Other major electricity generation technologies include gas turbines, hydro turbines, wind turbines, and solar photovoltaics.

Sources of US Electricity generation, 2017
Renewables 17% (hydro 7.5% - wind 6.3% - biomass 1.6% - solar 1.3% - geothermal 0.4%)
Petroleum 1%
Nuclearn 20%
Coal 30%
Natural gas 32%

Electricity is delivered to consumers through a complex network.

Electricity is generated at power plants and moves through a complex system, sometimes called the grid, of electricity substations, transformers, and power lines that connect electricity producers and consumers. Most local grids are interconnected for reliability and commercial purposes, forming larger, more dependable networks that enhance the coordination and planning of electricity supply.

In the United States, the entire electricity grid consists of hundreds of thousands of miles of high-voltage power lines and millions of miles of low-voltage power lines with distribution transformers that connect thousands of power plants to hundreds of millions of electricity customers all across the country. Our electric power grid is a 20th-century system providing electricity to a 21st-century, energy-hungry world. What can be done to make the grid more reliable and efficient?

The Grid

Although electricity is a clean and relatively safe form of energy, the generation and transmission of electricity affects the environment. Nearly all types of electric power plants have an effect on the environment, but some power plants have larger effects than others.

Let's Take a Look at Some Power Plan Examples:

North Steam Complex Plant	Hunter Power Plant

The two coal-fired power plants of the Crystal River North Steam Complex in Crystal River, Florida	Hunter Power Plant, a coal-fired power plant south of Castle Dale, Utah

The United States has laws that govern the effects that electricity generation and transmission have on the environment. The Clean Air Act regulates air pollutant emissions from most power plants. The U.S. Environmental Protection Agency (EPA) administers the Clean Air Act and sets emissions standards for power plants through various programs such as the Acid Rain Program. The Clean Air Act has helped to substantially reduce emissions of some major air pollutants in the United States.

The power plants can have a negative effect on the landscape and environment. Many power plants are large structures that alter the visual landscape. In general, the larger the structure, the more likely it is that the power plant will affect the visual landscape. Electricity transmission lines and the distribution infrastructure that carries electricity from power plants to customers also have environmental effects. Most transmission lines are above ground on large towers.

In the United States, about 67% of total electricity generation in 2016 was produced from: fossil fuels (coal, natural gas, and petroleum), materials that come from plants (biomass), and municipal and industrial wastes. Emissions that result from combustion of these fuels include:

Carbon dioxide (CO2)
Carbon monoxide (CO)
Sulfur dioxide (SO2)
Nitrogen oxides (NOx)
Particulate matter (PM)
Heavy metals such as mercury

Nearly all combustion byproducts have negative effects on the environment and human health:

CO2 is a greenhouse gas, and it contributes to the greenhouse effect.
SO2 causes acid rain, which is harmful to plants and to animals that live in water. SO2 also worsens respiratory illnesses and heart diseases, particularly in children and the elderly.
NOx contribute to ground level ozone, which irritates and damages the lungs.
PM results in hazy conditions in cites and scenic areas, and coupled with ozone, contributes to asthma and chronic bronchitis, especially in children and the elderly. Very small, or fine PM, is also believed to cause emphysema and lung cancer.
Heavy metals such as mercury are hazardous to human and animal health.

Electricity generation is one of the leading sources of greenhouse gas emissions in the United States. Power plants that burn fossil fuels or materials made from fossil fuels, and some geothermal power plants, are the sources of nearly 40% of total U.S. energy-related CO2.

Electricity Usage Challenge

Before You Go, You Need To Know

The following key points are from this explore section of the lesson. You must know the following information before moving to the next lesson. This is just a summary of the key points.

Define renewable resource
Understand why biomass, wind, solar, geothermal, and hydropower are considered renewable resources.
Understand the following about each energy source:
- How it is formed
- How it is used
- Pros and Cons with using this energy resource

IMAGES CREATED BY GAVS OR OPEN SOURCE