Experimenting withExperimenting withSolar-Electric Energy Solar-Electric Energy

Dr. Sandra Cruz-PolProfessor

Electrical and Computer Engineering

July 2, 20 08

An NSF Engineering Research Center for Collaborative Adaptive Sensing of the Atmosphere

Solar to electricity conversion

Prof. Agustin Irizarry, UPRM

We will use 2 types of electric connections

Series Connection

V= I R

Elements connect on ONE side only.

Parallel Connection

Elements connect on BOTH legs.

I = V / R

100mA

100mA

100mA

1.a. Series connection

+

1.5V

_

+

1.5V

_

+

1.5V

_

100mA

+

4.5V

_

P=VI

P= 100mA*4.5V

= 450mW

Three photovoltaic panels connected in series to feed a music box.

+

Series connection provides: 4.5V, 100mA

+

Music Box

Questions

Does the circuit works with solar and/or artificial light?

How does the sound varies with the intensity of light?

100mA

100mA

100mA

1.b Series connection with only 2 panels: less voltage

+

1.5V

_

+

1.5V

_

+

1.5V

_

100mA

+

3.0V

_

P=VI = power

P= 100mA*3V

= 300mW

Ej. Cell-phone charger, small radios

2.a Parallel connection

100mA+

1.5V

_

100mA+

1.5V

_

100mA

+

1.5V

_

300mA+

1.5V

_

P=VI

P= 300mA*1.5V

= 450 mW

All positives are connected together.

All negatives are connected together.

2.b Parallel connection with only 2 panels: less current

100mA+

1.5V

_

100mA+

1.5V

_

100mA

+

1.5V

_

200mA+

1.5V

_

P=VI

P= 200mA*1.5V

= 300 mW

Three photovoltaic panels connected in parallel to power either an LED light bulb or a fan.

+

Parallel connection provides: 1.5V, 300mA

or

Which connection to use?

Connection determines voltage and current.

Depends on the appliance to be connected, requirements.

Careful: if current is too large, it could damage the appliance.

Myth: Why is the Ocean Blue?

FALSE: The ocean is blue because the sky reflection on its surface.

TRUE: Water is blue. frequency spectra

But you need a huge amount of it to really see its color.

Look at a swimming pool as it gets deeper; even on cloudy days. http://ece.uprm.edu/~pol/OceanBlue.html

Who is Nikola Tesla?

Nikola Tesla – greatest contributor to Electricity. Invented ac motor, perfected dc motor, invented radio transmission, (wireless) designed Niagara Falls generator, distribution systems, fluorescence lamps, remote control, wireless, logic circuits, 3-phasic and many others.

Where to find this material?

http://ece.uprm.edu/~pol/maestros

**REMEMBER to give proper credit