APES 6.8 Solar Energy

Enduring Understanding:

Humans use energy from a variety of sources, resulting in positive and negative consequences.

Learning Objective:

Describe the use of solar energy in power generation.
Describe the effects of the use of solar energy in power generation on the environment.

Essential Knowledge:

Photovoltaic solar cells capture light energy from the sun and transform it directly into electrical energy. Their use is limited by the availability of sunlight.
Active solar energy systems use solar energy to heat a liquid through mechanical and electric equipment to collect and store the energy captured from the sun.
Passive solar energy systems absorb heat directly from the sun without the use of mechanical and electric equipment, and energy cannot be collected or stored.
Solar energy systems have low environmental impact and produce clean energy, but they can be expensive. Large solar energy farms may negatively impact desert ecosystems.

Types

When sunlight hits the various components in the photovoltaic cell, it releases electrons
As the electrons flow, it creates (or is,) electricity

Uses mechanical and electric equipment to transfer solar heated liquid to transfer heat or create electricity

Liquid is heated by concentrated solar beams
- Beams are concentrated by reflective surfaces
This water evaporates and turns into steam, turning a turbine, fueling a generator
Electricity is produced
This can also produce heat to be distributed wherever needed
- Like a home, water tank, etc.

Essentially, sunlight comes in from windows and heats the indoors
- Its important, however, that the windows face the right direction to maximize sunlight
- An overhang is also necessary to block higher elevation sunlight that would heat too much
This also requires good insulation and high thermal mass in the floors