Test your energy awareness by answering the quiz questions below. Many of the answers contain links to references, datasets or spreadsheets that can be used to further explore these topics.
The information in this quiz has been reviewed by a scientist.
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Which forms of energy are ultimately derived from solar energy?
- Nuclear energy
Biofuels derive energy from photosynthesis which is powered from the sun.
All fossil fuels can be thought of as "paleo-biofuels" and are a form of stored solar energy.
Wind energy is created by the uneven heating of the earth's surface, which is driven by solar input.
Nuclear energy is not derived from the sun. Nuclear energy comes from the energy released when atoms are split apart and some mass is converted to energy.
How much of the US energy use is supplied by renewable forms of energy?
82% of the US energy supply comes from fossil fuels, while 8.5% is from nuclear energy.
US Energy Consumption by Source, 2011, from the US Energy Information Administration
Which type of energy is expected make up the largest portion of the US energy supply in the year 2035?
- renewable energy
- liquid biofuels
- natural gas
- oil and other liquid fuels
- nuclear energy
According to projections, oil and other liquid fuels (which do not include biofuels) will continue to account for the largest source of energy in the US. In 2009, oil accounted for 37% of total US energy, while in 2035 oil is projected to supply 33% of the total US energy.
This data is from the Annual Energy Outlook 2011 by the US Energy Information Administration.
For a global perspective on future energy needs, see the World Energy Outlook.
Which nation uses the most gasoline per person?
- Russian Federation
- Saudi Arabia
- United Kingdom
- United States
The United States leads the way in gasoline use. In 2005, the per capita gasoline consumption was about 1.2 gallons per day.
Here is the per capita gasoline use of selected countries in 2005:
United States - 428 gallons per person per year
Canada - 316
Saudi Arabia - 185
Japan - 119
United Kingdom - 105
Germany - 93
Netherlands - 85
Russian Federation - 61
Data source EarthTrends Environmental Database
How we use energy: Transportation - from the National Academies of Sciences
Many nations have a governmental standard for the average fuel economy of all new passenger automobiles sold, such as the US Corporate Average Fuel Economy (CAFE) standard. Which regions have the most stringent requirement for automobile fuel economy?
- United States
- European Union
In 2006, the European Union and Japan led the world in fuel economy with requirements around 40 mpg.
China's standard is over 35 mpg while the US Corporate Average Fuel Economy (CAFE) standard is around 26 mpg in 2010.
Most nations, including the US, are implementing increasing standards over time.
US Last among Major Countries in Car Fuel Economy Standards
Graph of fuel economy data - from the article above
CAFE Standards by the National Academy of Sciences
The biggest use of energy in the typical US home is:
- Home electronics
- Water heating (such as for hot showers or laundry)
- Space heating (heating the house itself)
Cooling, water heating and lighting are the next largest users of energy in the home, each around 11%.
National Academy of Sciences, How we use Energy at Home and Work, 2006 data
US Energy Information Administration - Using and Saving Energy in Homes, 2005 data
If every American household replaced 3 incandescent light bulbs with compact fluorescent light bulbs, how would US carbon dioxide emissions change?
- 0.75% increase
- 0.1% decrease
- 1.5% decrease
- 5% decrease
- 7% decrease
1.5% decrease in total US carbon dioxide emissions.
This example illustrates the usefulness of doing some basic calculations to quantify the benefit of this energy-saving measure.
A simple Excel worksheet is included below that shows the steps used to calculate this answer; the spreadsheet allows students to modify some of the variables to further investigate this topic.
CFL worksheet (Excel 2007 (.xlsx) 13kB Dec14 10)
True or false: Every year, wind turbines kill more birds than domestic cats do.
In Denmark, where 9% of their electricity is generated by wind turbines, it was estimated that 30,000 birds are killed by wind turbines each year. While that is indeed a large number, it was also estimated that car traffic kills over one million birds per year in Denmark. In Britain domestic cats are responsible for 55 million bird deaths per year. This is not to say that bird kills are not a serious problem that merits careful attention, but a quantitative approach can illuminate the consequences of several different threats to birds. It should also be noted that the birds killed by wind turbines are typically raptors, while those preyed upon by cats are songbirds and other small species.
Source: Alternative Energy Without the Hot Air, by David MacKay http://www.inference.phy.cam.ac.uk/withouthotair/c10/page_63.shtml
Which single technology can provide our society with a seamless transition to cheap, safe and carbon-free energy?
- Electric cars
- Concentrating solar power
- Nuclear power
- Clean coal
- Hydrogen fuel cells
- Wind turbines
- Natural gas
None of the above.
There is no single "silver bullet" technology that will give us a simple transition to carbon-free energy for home heating, transportation, manufacturing and other large uses of energy. Every source of energy has its drawbacks and benefits, and a transition to new forms of energy will involve many different technologies, along with improvements in efficiency and changes in infrastructure.
What uses more energy? Six hours of laptop use or making coffee?
- Laptop uses more energy
- Coffee uses more energy
- They are about the same
They are about the same.
A laptop uses 15-60 watts of electricity. The exact amount depends on the type of laptop and the intensity of the use such as how many programs are open, if a CD is spinning, or if the hard drive is in frequent use. Six hours of laptop use at 45 watts equals 270 watt-hours.
Making coffee can be accomplished by several methods. A typical coffee maker uses 900 watts of electricity and runs for approximately 15 minutes, yielding 225 watt-hours of energy demand. To make coffee on the stovetop, an electric burner uses 2500 watts and takes about 5 minutes to boil a kettle of water. This works out to be 208 watt-hours.
You can see all the variables and fiddle with the numbers yourself by using this coffee vs computer spreadsheet (Excel 2007 (.xlsx) 12kB Dec14 10).
Handy reference: How much electricity does my stuff use? by Michael Bluejay
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