envs - renewable energy

environmental effect of hydropower?

- Changes in water temperature - Production of methane from decomposing matter - Loss of wildlife habitat

geothermal energy

- Geothermal energy has the potential to generate large amounts of electricity. Geothermal heat pumps can be used to cool buildings.

barriers to incorporating renewable energy technologies at a large scale in the United States?

- It is difficult to store energy produced by renewable technologies, specifically solar and wind. - Society in general has not made implementing renewable energy options a priority. - Energy infrastructure needs to be upgraded to match where energy is produced to where it is needed.

Some people argue that replacing gasoline with biofuels is an important step in transitioning from fossil fuels to renewable energy that must be completed right away, especially because we have the technology and resources to do it. While this argument may hold some validity, what drawbacks might these people be overlooking when making this argument? (Select the three correct answers.)

- It requires a lot of energy to convert biomass into biofuel. - Pure biofuels must be converted into usable forms, such as ethanol or biodiesel, before they can be used as a transportation fuel. - Mass production of some biofuels could potentially limit food supplies.

major environmental benefit of wind energy?

- Prevention of air pollution - Reduction of greenhouse gas emissions - Prevention of water pollution

why there are fewer limitations on solar energy use than there were in the past?

- The cost of solar panels has decreased significantly. - There have been advancements in battery storage systems.

Steps of how a hydrogen fuel cell works

1. oxygen is added to the negative cathode side of the fuel cell 2. hydrogen is added to the positive anode side of the fuel cell 3. at the anode, hydrogen atoms split into hydrogen ions and negative electrons 4. electrons cannot cross the membrane and instead flow through and electrical circuit to reach the cathode side. 4. electrons flowing through a circuit can be used to do work 5. at the cathode water is formed when the electron, H+ ions and oxygen react

Which of the following is NOT an environmental effect of hydropower?

Air pollution

Why is hydrogen hard to store?

As a liquid, it needs to be stored at very cold temperatures, and as a gas, the molecules tend to escape through tiny cracks in the containers.

Batteries could play an important role in helping renewable energy sources such as wind and solar contribute more to energy use. What is this role and why is it important?

Batteries store energy and in doing so help distribute energy from periodic renewable sources like wind and solar over a continuous period of time.

How could batteries help address some limitations of renewable energy?

By storing energy

Which of the following is true about atmospheric CO2 concentrations and biomass fuels?

Compared to gasoline, the use of ethanol results in only small reductions of greenhouse gases such as CO2.

main drawback to geothermal heating and cooling of buildings?

Cost of installation

In what ways do government policies inhibit the widespread use of solar and other renewable energy sources?

Current policies are built around a fossil fuel energy system.

One of the major concerns about current first-generation biomass fuels is that they take a lot of energy to produce and therefore won't help to reduce the emissions of greenhouse gases. Let's see if this is true in the following example: A gallon of gasoline releases about 9 kg CO2 when burned. If it takes about 2 kg of coal to produce the electricity to make one gallon of biofuel and each kilogram of coal results in the emission of 3.75 kg CO2, how much would CO2 emissions be reduced or increased by using biofuel instead of gasoline? You can assume that a gallon of biofuel and a gallon of gasoline have exactly the same amount of energy in them.

Decreased emission of 1.5 kg CO2

Even if the production of renewable energy sources increases quickly, these technologies are not likely to overtake fossil fuels as the major source of global energy over the next decade. Why?

Energy demand is growing fast, and renewable energy sources are not increasing fast enough to keep up with demand.

You know that the U.S. power generation system is fragmented; in fact, it is actually separated into three major grids with few connections between sections. However, you are wondering why these three grids don't just become separate grid systems that remain centralized but run completely on the renewable resources that are available in each respective section. What major issue still stands in the way of this plan to implement renewable power on a large, centralized scale in the future?

Energy from many renewable sources, such as solar and wind, are only available at certain times and are difficult to store for use during "off" times, regardless of the size or interconnectivity of the grid.

What is the difference between first- and second-generation biomass fuels?

First-generation biomass fuels are made from plant materials that can also be used as food, whereas second-generation fuels are made from non-food plant materials.

Which policy would cause the greatest increase in the United States' installed solar capacity?

Government investments in infrastructure and technology improvements

_________ is emitted as a result of electricity generation in a hydrogen fuel cell?

H2O

Which of the following types of renewable energy would be best able to provide base demand for electricity? (Base demand refers to the demand that is always present for power.)

Hydroelectric power

The Paris Agreement commits countries, including the United States, to a reduction in CO2 emissions. Which of the following actions would be the most likely to reduce CO2 emissions from the U.S.?

Increased use of solar photovoltaic systems

How does geothermal heat pump (residential) technology work?

It takes advantage of the relatively constant temperature of the surface of the earth to cool the house in the summer and warm it in the winter.

environmental impact resulting from the large arrays of reflectors in concentrated solar power plants?

Land disturbances, which impact wildlife

Developed countries have little potential for new large-scale hydropower projects. Why is this the case?

Many of the large rivers have already been dammed in developed countries.

While most of the major rivers in the United States could not support additional hydropower dams, which of the following statements describes a viable, cost-effective, and decentralized alternative that would still harness hydropower?

Micro-hydropower facilities could be installed that generate a lesser amount of electricity with low environmental impacts.

Which of the following is NOT a major environmental benefit of wind energy?

Protection of wildlife and aesthetics

What is the difference between renewable energy and sustainable energy?

Renewable energy resources cannot be used up, whereas sustainable energy can meet current and future needs without impacting future generations.

Which of the following statements is an accurate characterization of a potential benefit of second-generation biomass fuels as an energy source?

Second-generation biomass fuels would not require the use of food crops like corn and sugar cane.

How does concentrated solar thermal power differ from solar photovoltaic systems?

Solar photovoltaic power converts solar energy directly into electricity. Concentrated solar thermal power uses heat to turn a turbine.

Hydrogen power can be a renewable source of energy for transportation, but in some cases, it may not be much better than the use of fossil fuels. Why is this the case?

Some methods of acquiring hydrogen gas rely heavily on fossil fuels.

Which of the following is NOT a barrier to incorporating renewable energy technologies at a large scale in the United States?

The United States has few sources of renewable energy.

What generates the heat produced deep inside Earth?

The breakdown of radioactive elements in rocks Good job!

Why is there concern about the impact of biomass fuel production on food prices?

The diversion of food crops to energy production decreases the amount of food available for human consumption.

How are large hydropower dam projects and tidal energy facilities similar?

The energy of moving water is converted into the mechanical energy of a spinning turbine, generating electricity.

What is the main reason that wind cannot be used to provide all of the energy needed to meet electricity needs?

The grid cannot store electricity, and wind is an intermittent source of energy.

One day you are chatting with a friend about the environmental benefits of integrating large-scale renewable energy into the current power generation system. Your friend is skeptical and argues that there are well-documented impacts on wildlife and wildlife habitats How could you respond to demonstrate some of the positive benefits of renewable energy while balancing the environmental impacts that your friend mentions?

The integration of renewable energy on a large scale could drastically reduce CO2 and other pollutants in the air, which are currently damaging the environment for humans, plants, and animals alike at an alarming rate by causing climate change and widespread contamination.

What energy transformations are involved in the generation of electricity from wind energy?

The kinetic energy of wind is transformed into the mechanical energy of the spinning turbine shaft, which is converted to electrical energy.

best characterizes the size and current status of geothermal resources in the United States?

There is great resource potential in the country, but geothermal only accounts for a small portion of renewable energy used.

What is the difference between traditional biomass fuels and liquid biomass fuels?

Traditional biomass fuels are burned directly while liquid biomass fuels are synthesized from plants and algae.

How is electricity produced from moving water in a hydropower dam?

Water is stored as potential energy and turned into kinetic energy as it moves downhill through the dam and turns a turbine, creating electricity.

renewable energies that have potential for earthquakes

hydropower dams, geothermal energy electricity production

renewable energies that have negative impacts on wildlife

hydropower dams, solar power, wind energy

For a geothermal heat pump to work, the temperature of the ground has to be ______________ than the air in winter, and __________ in the summer

warmer, cooler