What does a solar photovoltaic (PV) panel produce directly?
AnswerElectricity
PV cells convert sunlight directly into direct-current electricity; solar thermal makes heat instead.
Science · Facts & stats
Solar facts & stats
8 fact-checked facts about solar power, from the sky to your roof, each with the reason behind it. 4 more are in today's round and join this page after it closes.
The basics
What is a kilowatt-hour (kWh)?
AnswerEnergy: one kilowatt used for one hour
Your electricity bill is in kWh; a 5 kW system in a sunny spot makes roughly 6,000 to 8,000 kWh a year.
Going deeper
What device converts panel DC power into AC for your home?
AnswerAn inverter
The inverter is the brains of a rooftop system and often the first component to need replacement.
Roughly how long do modern solar panels keep producing at least 80% of their rated output?
AnswerAbout 25 to 30 years
Most manufacturers warrant 80 to 87% output at 25 years; real degradation is around 0.5% a year.
Which US federal incentive reduced the cost of home solar in the 2020s?
AnswerA 30% investment tax credit
The residential clean energy credit covered 30% of system cost under the Inflation Reduction Act of 2022.
Community solar lets people do what?
AnswerSubscribe to a share of a shared solar farm without owning a roof
Renters and shaded homes can still get solar credits through community solar programs.
Expert level
Approximately how much did the cost of solar PV modules fall between 2010 and 2020?
AnswerAround 80 to 90%
IRENA and Lazard report module prices fell about 85 to 90% over the decade, making solar the cheapest new power in most places.
What is the theoretical efficiency limit of a single-junction silicon solar cell?
AnswerAbout 29 to 33% (Shockley–Queisser limit)
Single-junction cells are capped near 33%; commercial panels reach 20 to 23%, tandem cells can exceed the limit.
Know these cold?Today's round is five questions like these, 20 seconds each. Your streak and level follow you to every arena.Play today's round