Warm Up 1/31/14Voices are at “0”

1.In your opinion, which energy source is the best and why? List the pros & cons for your choice.

2.What did you do for fun on your “snow days”? How did you stay warm? What was your source of energy?

Missing Books

• I am missing 4 books. • I am offering a reward for any books returned,

no questions asked.• Please do not attempt to return books that

are already on my shelf – I am not stupid and I know what numbers are missing.

• Thank you for your cooperation in finding and returning my missing books!

Brainpop: Solar EnergyTime 2:59 minutes

Energizer – We will go over the quiz question by marching or waving hands

1.We will slash the trash for 2 answers2.Then you will Silently make a decision about

the other two by either drumming on the table or waving your hands

Solar Energy Basics Solar Energy Basics

Joe Rand Joe Rand KidWind ProjectKidWind Project

joe@kidwind.orgjoe@kidwind.org

Wind & Solar Energy Notes 3

• Draw a line under your last notes on page 3• Write SOLAR ENERGY• From this point forward, write down

everything in YELLOW

Solar Energy – A Bright Idea!

“I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait ‘til oil and coal run out before we tackle that.”

- Thomas Edison

People have been harnessing solar energy for a long time!

Solar collector forheating water

A home in California in 1906

Two Main Categories:Solar Thermal Solar Photovoltaic (PV)

Water heating and cooking Electricity production

Solar Thermal Energy

Cooking Water Heating

Solar CookingSolar Cooking

Benefits of Solar Cooking• Consumes no fuels/wood

– No loss of trees & habitat– Trees sequester carbon

• Generates no air pollution• Generates no greenhouse

gases• Produces no smoke

– Cooking smoke kills over 1.6 million people each year, mostly women & children, according to a recent report

• Eliminates fire dangers

More Benefits of Solar Cooking

• Eliminates work– No daily search for

firewood• 2 Billion people rely on

wood for cooking fuel!

– No risks to women and children

– Frees time for other activities

– No need to stir food– Helps to liberate women

More Benefits of Solar Cooking

• Cooks foods slowly and thoroughly

• Preserves nutrients • Foods will not burn• Pots are easy to clean;

less clean water is needed

• Use for canning vegetables

• Use for dried fruit• Kill insects in dry grains

Solar CookingHow Long Does it Take?

• Vegetables: 1.5 hrs• Rice/wheat: 1.5-2 hrs• Beans: 2-3 hrs• Meats: 1-3 hrs• Bread: 1-1.5 hrs

Solar Water Heating

• Solar water heating is the most efficient and economical use of solar energy

• Residential systems start at $2500 and typically cost $3500-$4500 installed

• Savings of $30-$75 per month, lasting 20 years

• Tax credits and state rebates available

Solar Water Heating

Solar Electric Solar Electric (Photovoltaic)(Photovoltaic)

• Photovoltaic (PV) systems convert light energy directly into electricity.

• Commonly known as “solar cells.” • The simplest systems power the small

calculators we use every day. More complicated systems will provide a large portion of the electricity in the near future.

• PV represents one of the most promising means of maintaining our energy intensive standard of living while not contributing to global warming and pollution.

Solar Electric Systems

How Does it Work?• Sunlight is composed of photons, or bundles of radiant

energy. When photons strike a PV cell, they may be reflected or absorbed (transmitted through the cell). Only the absorbed photons generate electricity. When the photons are absorbed, the energy of the photons is transferred to electrons in the atoms of the solar cell.

Best Place For Solar Panels?

• South Facing roof, adequate space

• No shading (time of year, future tree growth)

• Roof structure, condition

Large Scale PV Power Plants

Prescott AirportLocation: AZ

Operator: Arizona Public ServiceConfiguration: 1,450 kWp

SGS SolarLocation: AZ

Operator: Tucson Electric Power CoConfiguration: 3,200 kWp

ROXBORO, N.C. – A five-acre solar farm built by Durham-based Carolina Solar Energy in Person County is now online and feeding power to the grid of Progress Energy.The complex is expected to produce 837,000 kilowatt-hours of energy in the first year, enough for some 60 households based on an average annual usage of 14,000 kilowatt hours.Progress Energy is buying the power from Carolina Solar, which owns and operate the farm. The complex is located at the Person County Business and Industrial Center.Financial terms of the agreement have not been disclosed.Progress Energy is acquiring power from three solar farms, including one at SAS headquarters in Cary.State law requires Progress and other utilities to begin producing power from renewable sources. Progress Energy is exploring solar, wind, biowaste and other options to produce power from renewable sources. By 2012, companies have to get 3.5 percent of all retail sales from so-called renewables. The requirement jumps to 12.5 percent by 2021.Duke Energy is also involved in numerous solar and wind projects.

Centralized Wind-Solar Hybrid System

• In hybrid energy systems more than a single source of energy supplies the electricity.

• Wind and Solar compliment one another

Demo: How Does the Color/Wavelength of Light Affect PV Efficiency?

• Test 5-8 colors using different backgrounds on PowerPoint Slides– Purple– Blue– Green– Yellow– Orange– Red – White

Approximate Wavelength:390-455 nanometers

Approximate Wavelength:455-492 nanometers

Approximate Wavelength:492-577 nanometers

Approximate Wavelength:577-597 nanometers

Approximate Wavelength:597-622 nanometers

Approximate Wavelength:622-780 nanometers