Renewable Energy

Did You Know? 1. Which of the following is not an example of a potentially renewable or non-depletable energy source? Hydroelectricity Solar energy Nuclear energy Wind energy Geothermal energy

Nuclear energy Did You Know? 1. Which of the following is not an example of a potentially renewable or non-depletable energy source? Hydroelectricity Solar energy Nuclear energy Wind energy Geothermal energy

Definitions Potentially Renewable: Can be renewable if we do not consume them faster than they can be replaced (ex: biomass) Non-depletable: Cannot be depleted no matter how much we use them (ex: solar, wind, geothermal, hydroelectric and tidal energy) Renewable: Potentially renewable and non-depletable resources together

Did You Know? 2. The primary sources of renewable energy in the United States are? solar and wind energy. hydroelectricity and tidal energy. biomass and hydroelectricity. geothermal and tidal energy. wind and geothermal energy.

biomass and hydroelectricity. Did You Know? 2. The primary sources of renewable energy in the United States are? solar and wind energy. hydroelectricity and tidal energy. biomass and hydroelectricity. geothermal and tidal energy. wind and geothermal energy.

U.S. Energy Consumption 2013

U.S. Per Capita Energy Use

Did You Know? 3. Which of the following best describes U.S. energy use? Transportation is the largest end use of energy in the United States. Transportation is fueled mainly by coal. Electricity generation is the largest end use of energy in the United States. Electricity generation is powered mainly by nuclear energy. Industry is the largest end use of energy in the United States.

Did You Know? 3. Which of the following best describes U.S. energy use? Transportation is the largest end use of energy in the United States. Transportation is fueled mainly by coal. Electricity generation is the largest end use of energy in the United States. Electricity generation is powered mainly by nuclear energy. Industry is the largest end use of energy in the United States.

U.S. Energy Consumption by Sector 2013

useful energy output / total energy input Energy Efficiency = useful energy output / total energy input This will give you a decimal number between 0 and 1, but efficiency looks better as a percentage. Multiply the efficiency by 100 to get this. Due to the principle of conservation of energy, energy efficiency within a closed system can never exceed 100%.

R-value Measurement of how effectively a material resists the transfer of heat via conduction. The higher the R-value, the less heat transfer can take place.

Did You Know? 4. An energy-efficient building might include all of the following except? building materials with low thermal inertia. a green roof. southern exposure with large double-paned windows. reused or recycled construction materials. photovoltaic cells.

Did You Know? building materials with low thermal inertia. 4. An energy-efficient building might include all of the following except? building materials with low thermal inertia. a green roof. southern exposure with large double-paned windows. reused or recycled construction materials. photovoltaic cells.

Passive Solar Heating Captures sunlight directly within a structure and converts it into low-temperature heat for space heating.

Active Solar Heating Special collectors absorb solar energy; a fan or pump is used to circulate the hot water.

Photovoltaic Cells PV (Solar Cells) - Sunlight falling on a wafer thin silicon sheet releases a flow of electrons creating an electric current. High net energy yield; and still functions in cloudy weather Cost of PVs is high Storage of electricity produced is a problem Data Table

Photovoltaic Cells Photovoltaic is the direct conversion of light into electricity at the atomic level. Some materials exhibit a property known as the photoelectric effect that causes them to absorb photons of light and release electrons. When these free electrons are captured, an electric current results that can be used as electricity.

Sunlight hits the surface of the photovoltaic cell. A material called a semi-conductor converts the light into electricity. Reflectors concentrate the sun's rays to heat a special kind of liquid. The heat from this liquid boils water to create steam. Steam spins a turbine that is connected to a generator, which creates electricity.

Concentrated Solar Thermal Power

Concentrated Solar Thermal Power

Fuel Cell A fuel cell is an electrochemical device that combines hydrogen and oxygen to produce electricity, with water and heat as its by-product.  As long as fuel is supplied, the fuel cell will continue to generate power.  Since the conversion of the fuel to energy takes place via an electrochemical process, not combustion, the process is clean, quiet and highly efficient – two to three times more efficient than fuel burning.

Fuel Cell

Wind Power Producing electricity from Wind: Unlimited source at favorable sites Land underneath turbines can be used for grazing cattle or farming Need steady winds Fastest growing energy source in the world since 1990 Data Table

As the wind blows over the blades of a wind turbine it causes the blades to lift and rotate…The rotating blades turn a shaft connected to a generator…The generator creates electricity as it turns.

U.S. Onshore Wind Power Potential

U.S. Offshore Wind Power Potential

Hydroelectric Power Second most common form of renewable energy in the U.S. and the world. Most widely used form of renewable energy for electricity generation. 3 Types: Water Impoundment Hydroelectric Dam Run-of-the-River Tidal Systems Moderate to high net energy yield Flood vast areas, destroy wildlife habitat, uproots people Data Table

Hydroelectric Dam

Run-of-the-River

Tidal Power

Did You Know? 5. All of the following are negative environmental impacts of hydroelectric power except Damming rivers destroys habitat Damming disrupts the natural flooding of rivers Hydroelectric power contributes directly to acid rain Hydroelectric dams can create thermal pollution downstream Sediment, and nutrients, are trapped behind dams

Did You Know? 5. All of the following are negative environmental impacts of hydroelectric power except Damming rivers destroys habitat Damming disrupts the natural flooding of rivers Hydroelectric power contributes directly to acid rain Hydroelectric dams can create thermal pollution downstream Sediment, and nutrients, are trapped behind dams

Producing Energy from Biomass Organic matter can be burned directly as a solid fuel, or converted into gaseous or liquid biofuels. Solid biofuels: wood, charcoal, dried manure First Generation Biofuels: ethanol, biodiesel, methanol, butanol, biogas Flex-fuel vehicles can run on either gasoline or E-85 Potentially renewable if managed properly

Producing Energy from Biomass Biomass = Modern Carbon Burning biomass sustainably is Carbon Neutral because the resulting carbon is absorbed by the next year’s growth of biomass. Fossil Fuels = Fossil Carbon Fossil Carbon has been buried for millions of years. The burning of fossil fuels results in an increase in atmospheric and oceanic CO2 levels.

Biofuel Drawbacks Require large areas of land “Food vs. Fuel” = increased food prices Increase soil erosion Air pollution Deforestation - can compete for land that would otherwise be available as wildlife habitat Data Table

U.S. Geothermal Energy Potential

Power from th earth

Geothermal Energy

Did You Know? 6. Which of the following sources of energy is not ultimately solar-based? Wind Biomass Tides Coal Hydroelectricity

Did You Know? 6. Which of the following sources of energy is not ultimately solar-based? Wind Biomass Tides Coal Hydroelectricity

Did You Know? 7. The environmental impacts of cutting down a forest to obtain wood for fuel for heating and cooking could include? deforestation and subsequent soil erosion. release of particulate matter into the air. a large net rise in atmospheric concentrations of sulfur dioxide. I only II only III only I and II II and III

Did You Know? 7. The environmental impacts of cutting down a forest to obtain wood for fuel for heating and cooking could include? deforestation and subsequent soil erosion. release of particulate matter into the air. a large net rise in atmospheric concentrations of sulfur dioxide. I only II only III only I and II II and III

What the government can do: increase fuel efficiency standards for motor vehicles establish energy-efficiency standards for buildings and appliances increase government sponsored R&D to improve energy efficiency give tax credits and exemptions for purchases of energy efficient vehicles, houses, buildings and appliances phase in full-cost pricing to include the environmental impact

Quick Review

Did You Know? 8. Which of the following statements best describes the role of renewable energy in the United States? It is the dominant source of energy. It is the largest contributor of greenhouse gases. It is a large contributor to the transportation sector. Its largest contribution is to the electricity generation sector. It is never sustainable.

Did You Know? 8. Which of the following statements best describes the role of renewable energy in the United States? It is the dominant source of energy. It is the largest contributor of greenhouse gases. It is a large contributor to the transportation sector. Its largest contribution is to the electricity generation sector. It is never sustainable.