Quiz
The Student Guide and Science of Solar – Starter Pack contain the quiz and cloze notes.
Answer Key: Q1:B Q2:A Q3:C Q4:C
Reading and Extended Reading
The Student Guide contains the Science of Solar – Reading and Extended Reading info sheets.
Reading Answer Key
- Solar energy is energy that comes from the Sun.
- Photovoltaic cells convert sunlight into electricity.
- Solar panels capture sunlight and convert it into electricity using photovoltaic cells.
- Active systems use mechanical devices like solar panels to capture sunlight, while passive systems use building design and materials to naturally capture and store solar energy.
- Silicon is most commonly used in solar cells.
- Sunlight excites the electrons in the solar cell material, causing them to move, creating an electric current.
- Solar energy itself does not produce carbon dioxide or other harmful gases, unlike hydrocarbons but there is an environmental impact from the mining, processing, and transportation of the rare earth materials needed for the solar panels.
- The main disadvantage is that solar energy is intermittent, meaning it is not available at night or on cloudy days.
- Solar energy can be stored using batteries or other energy storage systems.
- Good solar orientation helps capture sunlight to naturally heat the building, especially in winter.
- Thermal mass refers to materials like concrete or brick that absorb sunlight during the day and release it slowly at night, keeping the building warm.
- Storing solar energy is difficult because it requires special batteries or storage systems, which can be expensive and have limited capacity.
- Solar energy provides an alternative to burning hydrocarbons for electricity, helping to reduce reliance on non-renewable sources.
- Solar panels can save money on electricity bills over time, making it a worthwhile long-term investment.
- Solar energy is sustainable because it comes from the Sun, which will continue to shine for billions of years, and it does not harm the environment by releasing emissions
Extended Reading Answer Key
- Solar energy is energy derived from the Sun.
- Photovoltaic cells convert sunlight directly into electricity.
- Solar orientation refers to positioning a building to maximize sunlight exposure, especially through south-facing windows.
- Thermal mass stores and slowly releases heat, helping maintain stable indoor temperatures.
- The p-n junction creates an electric field that drives the flow of electrons, generating electricity when sunlight hits the solar cell.
- Doping introduces impurities to silicon, creating p-type and n-type layers that allow electrons to flow and generate electricity.
- Active systems use mechanical devices like solar panels to convert solar energy, while passive systems rely on building design and materials to naturally capture and store solar energy.
- The primary environmental benefit is that solar power generates electricity without emitting carbon dioxide or other greenhouse gases.
- One challenge is the intermittency of solar energy, as it is only available when the Sun is shining.
- Energy storage is important because solar power is intermittent, and storage ensures electricity is available when the Sun isn’t shining.
- Lithium-ion batteries store excess solar energy during the day for use at night or on cloudy days.
- Pumped hydro storage uses excess solar energy to pump water to a higher elevation, which can later be released to generate electricity.
- Solar energy is considered sustainable because the Sun provides an almost unlimited supply of energy, unlike finite hydrocarbons.
- Economic advantages include low operational costs after installation, job creation in the solar industry, and reduced reliance on imported hydrocarbons .
- Disadvantages include the high initial installation costs and the need for energy storage solutions due to intermittency.
- Answers will vary, but a possible strong response might include reducing the cost of solar panel production or improving energy storage technologies.
- Solar energy could reduce the demand for hydrocarbons, decrease energy prices, and shift global energy markets toward more sustainable sources.
- Rooftop solar panels would reduce land use and habitat disruption while still capturing sunlight efficiently, helping minimize environmental impacts.
- Manufacturing solar panels requires raw materials and energy, but once installed, solar panels produce no emissions. In contrast, burning hydrocarbons for electricity emits greenhouse gases and contributes to environmental degradation.
- One solution is using energy storage systems like batteries or pumped hydro storage to store excess energy for use when sunlight is not available.
Computation
The Student Guide contains the Science of Solar Computation activity.
Answer Key:
Q1: (5000 watt/generator) x (1 panel/200 watt) = (5,000 panel/200 generators) = 25 panels/1 generator
Q2: A) Daily output per panel = 300 W × 5 h = 1,500 kWh = 1.5 kWh
Annual output = 1.5 kWh × 365 = 547.5 kWh
B) Number of panels = 900,000 kWh ÷ 547.5 kWh ≈ 1,644 panels
C) Improved output = 547.5 kWh × .20 = 109.5 kWh 547.5 kWh + 109.5 kWh = 657 kWh
Panels needed = 900,000 kWh ÷ 657 kWh/panel ≈ 1,370 panels
Panels saved = 1,645 panels – 1,370 panels = 275 panels
Q3: A) Daily output per home = 6 kW × 4 h = 24 kWh
Annual output per home = 24 kWh × 365 = 8,760 kWh
Total annual output for 1,250 homes = 8,760 kWh × 1,250 homes = 10,950,000 kWh
B) Total CO₂ avoided = 10,950,000 kWh × 0.5 kg/kWh = 5,475,000 kgConvert to metric tons: 5,475,000 kg ÷ 1,000 = 5,475 metric tons CO₂ avoided annually
Data Set
The Student Guide contains the Science of Solar – Data Set.
Answer Key: Question 1: Total = 49.84 + 834.10 + 70.99 + 133.81 + 303.17 = 1391.91
China’s share = 834.10 ÷ 1391.91 ≈ 60%
Question 2: Answers will vary. (Example: Australia may have less developed solar infrastructure or lower energy demand due to its smaller population, while Germany has made significant investments and policies supporting solar energy, leading to higher production relative to its size.)
Question 3: Answers will vary. (Example: China’s far higher solar production suggests greater government investment, stronger policy incentives, or higher national energy demand compared to Australia.)
Question 4: Answers will vary. Question 5: Answers will vary.
Solar Panel Energy Lab
The Student Guide contains the Solar Panel Energy Lab – Student questions.
Lab Question Answer: A. angle of the solar panel B. electricity C. light intensity, type of solar panel, distance from the light source
Hypothesis Example: Answers will vary. (Example: If the solar panel is angled to face the light source directly, then it will produce the most electricity.)
Analysis Questions: Answers will vary.