1. Photovoltaics (PV)
Mr. Huebsch

2. Behavioral Objectives
History
How a photovoltaic cell works
Types of Cells
Grid tied or Off Grid
How does PV lower carbon in the atmosphere
Photovoltaic uses
Pros and Cons

3. History of Photovoltaics
Photo stems from Phos which is Greek for light.
Volt is after Alessandro Volta, a pioneer in the study of electricity.
“Light Energy”
Basic science of it was discovered in 1839
Albert Einstien wins nobel prize for paper on photoelectric effect in 1922
The commercial solar age begins in 1954
1990 Progressive Governments Use Subsidies to Speed Adoption

4. How Does a Cell Work
Made of semiconductor materials such as silicone or cadmium sulfide
Using semiconductor-based technology, Photovoltaic cells (PV) directly convert light energy into electrical current.
DC power - inverter -Utility AC disconnect - sub panel - meter pan - utility grid

5. Types of PV Cells Monocrystalline
made by crystallizing melted silicon into an ingot. The ingot is then cut into slices to make individual cells. The cells are usually blue or black in color.
Most efficient, most expensive and Fragile
Polycrystalline
cells are cut directly from a large piece of silicon rather than one large crystal.
Less expensive, less efficient and Fragile
Amorphous
No specific crystalline structure. These cells, also known as thin- film, are the result of vaporizing silicon through a vacuum in very thin layers on a wide choice of surfaces such as plastic or glass.
Loss of power over time.

6. Grid Tied Spins Your Meter Backwards
Solar panels connected to the utility electric grid are “net metered.”
Solar panels provide electricity during the day for use in the home.
Excess electricity spins your meter backwards and is sold back to the utility.
At night, or when additional power is needed, the utility provides conventional electricity to the home.

7. Off Grid Independent Power
PV modules feed energy into battery storage.
Energy is available to user day and night.

8. Photovoltaic uses

11. Reducing Carbon footprint
Over 25 Years, a typical 3kW Solar Electric System will offset the following:
180,000 lbs of CO2 (greenhouse gas)
300,000 miles driven in an average car (at 12,000 Miles a Year)
Protects our air quality, equal to planting
1.5 acres of trees
Prevents more than 90,000 lbs. of fossil fuel from being burned

12. Pros Sustainable source of clean energy High reliability
Used in space: powers every satellite circling earth
No maintenance
Lower operating cost
Clean and silent
Can provide as little or as much power as you need

13. Cons Need sunlight Easy to destroy Expensive
Need large southern exposure area on your property
If grid tied you still loose power when the power goes out.
Off grid system requires several batteries