6.8 Solar Energy

• What is the primary source of solar energy?

  Nuclear fusion reactions
• Solar energy is measured in terms of irradiance
• Solar irradiance is calculated using the formula $I =$$\frac{P}{A}$
• Match the solar energy technology with its description:

  Solar PV ↔️ Converts sunlight directly into electricity

  Solar Thermal Systems ↔️ Uses sunlight to heat water or air

  CSP ↔️ Concentrates sunlight to heat a fluid
• Solar photovoltaic cells use semiconductor materials to convert sunlight into electricity.
• Steps involved in the photovoltaic effect:

  1️⃣ Photons strike semiconductor material

  2️⃣ Photons transfer energy to electrons

  3️⃣ Energized electrons create current

  4️⃣ Current is harnessed for use
• The photovoltaic effect converts sunlight directly into electricity.
• Passive solar heating maximizes sunlight intake for heating
• Match the solar thermal system with its application:

  Passive Solar Heating ↔️ Residential heating

  Active Solar Heating ↔️ Water heating
• What do solar thermal systems use sunlight for?

  Heating water or air
• Solar thermal systems collect solar energy using collectors
• Solar thermal systems store heat for later use.
• What fluid is commonly heated in solar thermal systems?

  Water or air
• Solar thermal systems use sunlight to heat a fluid, which is then used directly or stored for later use
• The primary use of solar thermal systems is to generate electricity.

  False
• Match the benefit of solar thermal systems with its description:

  Cost-effective for heating ↔️ Lower heating expenses

  Can store heat ↔️ Heat can be used later
• What is a drawback of solar thermal systems in low sunlight conditions?

  Less efficient
• Solar water heaters use solar thermal systems to heat water for household use
• Solar thermal systems can generate electricity.

  False
• Match the primary use of solar thermal systems with its description:

  Heating water or air ↔️ For domestic or industrial purposes

  Storing heat ↔️ For later use when needed
• What is the primary source of solar energy?

  Nuclear fusion
• The amount of sunlight that reaches Earth is measured as solar irradiance
• What is the formula for solar irradiance?

  $I =$$\frac{P}{A}$
• In the solar irradiance formula, P represents power and A represents area.
• Match the solar energy technology with its description:

  Solar Photovoltaic (PV) ↔️ Converts sunlight into electricity

  Solar Thermal Systems ↔️ Uses sunlight to heat water or air

  Concentrated Solar Power (CSP) ↔️ Concentrates sunlight to power turbines
• What material do Solar Photovoltaic (PV) cells use to convert sunlight into electricity?

  Semiconductor materials
• Solar Photovoltaic (PV) systems have lower operational costs
• Solar Thermal Systems are cost-effective for electricity generation.

  False
• What is a major drawback of Concentrated Solar Power (CSP) systems?

  Requires large land areas
• What do Solar Photovoltaic (PV) cells convert sunlight into?

  Electricity
• Solar Thermal Systems use sunlight to heat water or air
• How does Concentrated Solar Power (CSP) generate electricity?

  Heats a fluid
• Match the solar energy technology with its description:

  Solar Photovoltaic (PV) ↔️ Converts sunlight into electricity

  Solar Thermal Systems ↔️ Heats water or air using sunlight

  Concentrated Solar Power (CSP) ↔️ Generates electricity by concentrating sunlight
• Solar PV systems have high operational costs.

  False
• Solar Thermal Systems are cost-effective for heating
• What is a major drawback of CSP technology?

  Requires large land areas
• Solar energy technologies reduce reliance on fossil fuels.
• What materials are used in Solar Photovoltaic (PV) cells to convert sunlight into electricity?

  Semiconductors
• Steps of the photovoltaic (PV) effect:

  1️⃣ Sunlight hits the PV cell

  2️⃣ Photons transfer energy to electrons

  3️⃣ Energized electrons create electric current

  4️⃣ Current collected and sent through a circuit
• The photovoltaic (PV) effect converts sunlight directly into electricity