Solar
What is renewable energy?
Renewable energy is energy from sources that are constantly formed and so will NEVER run out.
What is biomass? What are some examples of biomass fuel?
Organic material that can be used as a fuel.
Examples - Wood, animal dung, methane made from landfills or even animal dung, alcohol from fermented fruit or agricultural wastes (ethanol), etc.
What is alternative energy?
Energy sources that are still in development - must be cost effective and have minimal environmental impact.
What are three advantages to hydroelectricity?
Flood control, no air pollution, cheap to maintain, irrigation, human water supply.
What is energy efficiency?
What is most energy lost as?
The percentage of energy put into a system that does useful work.
Heat.
What are three advantages to solar energy?
No moving parts.
Energy independence.
Cells are becoming more efficient and less expensive with time. Currently they are very efficient and cost effective.
Can generate electricity in any climate, and in any place - more useful in certain places, but still.
No emissions.
What gas is produced by biomass in landfills? How do landfills account for / use this gas?
Methane - Landfills break down biomass to produce methane which is captured and used for heating / electricity production. Decomposition also produces CO2.
Why are electric cars so much more efficient than gas cars? Where is the energy loss?
In gasoline engines, much of the energy is lost – only 12 – 30% of the energy from fuel is used to power the car. Rest is lost as heat, friction, etc.
In electric cars, 80-85% of the energy from the battery is used to power the car.
What are three disadvantages to hydroelectricity?
Can change the ecosystem of the river, can displace people and wildlife, lesser water quality due to pathogens / bacteria, expensive to install.
Could our electricity needs in the U.S. be met by renewable resources?
What about the world's electricity needs?
If so, what would be the main renewables that would be used? If not, what is holding society back?
Yes.
Yes.
Wind, Solar - also supported by geothermal, hydroelectric, and biomass.
What is passive solar heating? Describe the process in as much detail as you can.
Passive - Absorbs and stores heat from the sun directly within a structure without the need for pumps to distribute the heat.
What are three disadvantages of using biomass fuel?
Habitat loss, soil erosion, and air pollution.
How does Ocean Thermal Energy Conversion (OTEC) work?
* You are using the temperature difference in sea water to generate energy.
•Warm surface water on the ocean is used to boil cold, deeper sea water.
•Water boils at low temperatures when it is at low pressure in a vacuum.
•Steam is then used to power a turbine and generate electricity.
What is the name of the world's largest geothermal plant? Where is it located?
How many homes does it power? (extra)
"The Geysers" in California. Powers ~1.7million homes.
More than 40% of all commercial energy is wasted by what? (list at least 3)
Combustion engine vehicles, furnaces, poorly insulated buildings, and incandescent light bulbs.
What are three disadvantages to solar energy?
Uses a lot of space, requires extended periods of sunshine - reliant on the sun, high initial cost - high emissions from construction.
In our biofuel lab with yeast, what process was taking place? What was being used, and what was being produced in the flask? Why was the balloon expanding?
Fermentation.
Sugars were used to produced ethanol and CO2 (byproduct).
The balloons expanded due to CO2 gas.
What are the disadvantages of hydrogen fuel cells?
Not cost effective YET, can be dangerous due to hydrogen gas - highly flammable, storage issues, and most importantly we do not have natural stores of hydrogen on earth so we need to extract it - 95% of this comes from methane (natural gas)... so we are using fossil fuels to even harvest this alternative energy.
Where can a geothermal power plant be located? Where is the energy coming from?
In areas where deposits of water are heated inside the Earth. Hot water or steam is pumped from the rocks. Steam powers turbines which generate electricity.
What is cogeneration? Describe how the process would work.
The production of two useful forms of energy from a single source.
An example is waste heat from an industrial furnace that can be used to power a steam turbine to produce electricity.
What is active solar heating? Describe the process in as much detail as you can.
Was our pizza box solar oven an example of passive or active solar heating?
Active - We can heat buildings by orienting them towards the sun or by pumping a liquid such as water through rooftop collectors.
Passive!
What is wind / why does it exist?
What are the pros and cons of wind energy? Provide 2 reasons for each.
The sun warms the earth’s surface unevenly, resulting in flowing air masses we call wind.
Positive - Wind farms are cost effective, work in a variety of places, create no pollution, efficient.
Negative - Sometimes unreliable / unpredictable (need to have a backup), noisy, dangerous / disrupting to some wildlife depending on placement (but impact is very minimal and overstated), electricity must be transported from rural areas (the farms) to urban centers (people).
What are the advantages of hydrogen fuel cells?
No pollution from the actual cell itself - produces H2O as a byproduct, hydrogen is the most abundant element in the universe - we have plenty to use if we can harvest it in a better way (electrolysis), more efficient than fossil fuels, renewable.
Why would putting solar panels in a water reservoir be a great idea? Give me at least two reasons why.
Provides shade to the water, reducing evaporation to save up to 90% of water that may be lost in drier climates.
Reduces the heating of water, and the lower levels of light reaching the water combined have the benefit of reducing algal growth. Improved water quality - more oxygen rich.
What are 7 ways you could practice energy conservation in your own life?
Turning off appliances / lights when not needed.
Using LED bulbs.
Using a fuel efficient car.
Using public transport.
Washing clothes in cold water.
Insulating your home.
Turning thermostats down in winter and up in summer.
Using a microwave rather than a stove to cook small portions of food.
Only washing full loads of laundry, dishes, etc.