Solar Quiz: How Much Do You Know About Solar Power?
Are you an energy whiz? Find out with this quiz!
By Megan Phelps
How much do you know about solar energy? Here’s your chance to test your knowledge. Below are 10 questions — all true/false, and all about solar-electric systems. Jot down your choices, then scroll to the bottom of the page to see the answers and add up your score.
The Questions: True or False?
- Scientists discovered “the photovoltaic effect”— the concept that light could produce electric current — in 1939.
- Most solar cells are made from amorphous silicon.
- Solar cells can be made from plastic.
- Most solar cells are about 60 percent efficient at converting sunlight into electricity.
- A solar panel produces DC power — an inverter converts it to AC.
- A typical size for a residential solar-electric system is between 2,000 and 5,000 watts.
- Net-metering laws and feed-in tariffs are both policies that help homeowners get paid more for the electricity their solar panels produce.
- Over the course of a year, a photovoltaic (PV) system in Albuquerque, N.M., would produce almost exactly the same amount of electricity as an identical PV system located in Seattle.
- The United States currently produces more electricity from solar power than it does from wind power.
- New Jersey has more PV power installed than any other state.
- False. It was actually 100 years earlier than that — 1839.
Learn more: This Month in Physics History, from the American Physical Society.
- False. Most solar cells are made of crystalline silicon. The alternative is thin-film solar, which is growing, but not yet as common as crystalline modules. Amorphous silicon is just one material used to make thin-film solar panels.
Learn more: How Thin-film Solar Cells Work, from How Stuff Works. Also, here’s a table from the Energy Information Administration (EIA) showing how production of thin-film solar compares to the production of crystalline silicon modules.
- True! Plastic solar cells are one type of thin-film solar cell being developed.
Learn more: Information about plastic solar cells from Science Daily.
- False. The most efficient solar products are closer to 20 percent efficient. In the lab, the record is nearer to 40 percent.
Learn more: New Solar Cell Efficiency Record Set, from Scientific American.
- True. The inverter is needed because our homes run on AC power.
Learn more: Information about how solar systems work from the EIA.
- True. The trick here is that you'd be more likely to see that number expressed as 2 to 5 kilowatts. (1 kilowatt = 1,000 watts.) Learn more: Size and cost of a solar-electric system from MOTHER EARTH NEWS. Also, here’s a table from the EIA explaining the units of electricity.
True, and award yourself one bonus point if you’ve ever heard of a feed-in-tariff (FIT) — two if you can define it. If you install a grid-tied photovoltaic (PV) system, you’re in the business of selling electricity to your utility company. Both FITs and net-metering policies set rules about how much you get paid for the electricity your solar panels produce.
Learn more: Our friend Dan Lepinski, co-host of MOTHER EARTH NEWS Radio, has written a glossary of renewable energy terms. Find it on the website of the North Texas Renewable Energy Group. It includes technical definitions of both net metering and FITs.
False. More sun equals more solar electricity, so a PV system in sunny Albuquerque would definitely produce more power over the course of a year than an equivalent PV system in rainy Seattle.
Learn more: Calculating Solar Power Potential with PV Watts, from MOTHER EARTH NEWS.
False. Wind power production is currently much bigger than solar power production.
Learn more: Here’s a big table of electricity statistics from the EIA.
False. California is by far the U.S. leader in solar power. However, New Jersey is No. 2.
Learn more: The Best States for Solar Power, from MOTHER EARTH NEWS.
Add Up Your Score!
How many did you get right?
10+: You have the (solar-electric) power!
7 to 9: Well done. The sun is shining on you.
4 to 6: Not bad, but keep working on your efficiency.
0 to 3: You're still in the dark. Try again!
Photo by iStockphoto