Basics of photovoltaic systems for grid-tied applications
 Basics of Photovoltaic systems for grid-tied applications
Presentation by Peter Shoemaker & PG&E energy training center
The state has established a goal to become less dependent of fossil fuels and reduce carbon emissions. This goal requires 33 percent of California’s energy to be produced from renewable energy sources by 2017. Currently, PG&E is working with Solel-MSP-1 to construct a 553 megawatt commercial solar system to be completed by 2011. California is the countries leader in solar technology with 40% of all grid tied systems being located in this state. For people who are unavailable to have their own renewable energy system PG&E offers a program called ClimateSmart which adds additional cost to your bill which is spent on programs that offset your carbon production.
 Facts on solar power
Photovoltaic (PV) systems convert sunlight directly into electricity by means of semiconductors.
AC current flows back and forth 60 times per second and can be transferred much easier than DC current which PV panels produce. Crystalline Silicon Mono was made in 1953 becoming the oldest type of material used. It was first pushed by the government's space program and has the highest efficiency rating.
PV panels produce DC current which can be directly stored in a battery unit. An inverter is needed to convert electricity from DC to AC current for household or gird-tied application.
A system that produces equivalent power using less square footage is more efficient.
A cell is a single piece of PV material that is approximately 6x6 inch square. A module or panel is made up of several cells tied together in series and an array is a series of panels wired together.
There are currently three different kinds of PV material.
- Crystalline Silicon Poly & Mono
- Highest efficiency averaging 15%-22%
- 100 square feet per kilowatt
- Makes up 85% of market
- Proven reliability; used over 50 years
- Firm hard construction
- Thin-Film PV Products
- Lower efficiency averaging 7%-15%
- 200 square feet per kilowatt
- new technology that has not been thoroughly tested for longevity
- Production is growing at high rate
- Applied to many to materials and applications
- Can cost less than crystalline but requires much more space
- Flexible construction
This is a brief overview of relative electrical terms and simple definition.
- Volts are pressure
- Amps are current
- Watts are output
- Amps x Volts = Watts
- 1 Kilowatt = 1,000 Watts
- 1 Megawatt = 1,000,000 Watts
- Photo = light
- Voltaic = produces voltage