Soaking Up Some RaysSoaking Up Some Rays

A New Era in Solar EnergyA New Era in Solar Energy

By Jim LehmanBy Jim Lehman

What doWhat do

&

Have in common?

They convert energy from They convert energy from sunlight to other formssunlight to other forms

EnergyEnergy

What is Energy?What is Energy?

Energy is often Energy is often defined as the ability defined as the ability to do workto do work

Energy comes in Energy comes in many different formsmany different forms

Forms of EnergyForms of EnergyHow many forms of energy can you list?

Activity: Activity: Energy DetectivesEnergy Detectives

You will be given some Energy SpheresYou will be given some Energy SpheresFollow the directions on the cardFollow the directions on the cardMake observations about the spheresMake observations about the spheres– Observations use the senses or instrumentsObservations use the senses or instruments

Make inferences about the Energy Make inferences about the Energy SpheresSpheres– Inferences are guesses based on Inferences are guesses based on

observationsobservations

What do What do YouYou Know about Energy Know about Energy Transformations?Transformations?

How many examples can you think of How many examples can you think of where energy changes from one form to where energy changes from one form to another?another?

Some energy transformations are more Some energy transformations are more efficient than othersefficient than others

EfficiencyEfficiency

Many energy conversions waste more Many energy conversions waste more than half of the original energythan half of the original energy

How efficient is a car?How efficient is a car?

http://auto.howstuffworks.com/fuel-cell4.htm

Heat: A Major CulpritHeat: A Major Culprit

Many energy transformations “Lose” Many energy transformations “Lose” energy when heat is given offenergy when heat is given off

Can you think of examples of energy Can you think of examples of energy conversions where energy is wasted as conversions where energy is wasted as heat?heat?

Example: Incandescent lampExample: Incandescent lamp

Checking Your UnderstandingChecking Your Understanding

Identify these energy Identify these energy transformations: transformations:

Photovoltaic Solar PowerPhotovoltaic Solar Power

Light energy Light energy →→ electrical energy electrical energy

AbundantAbundant

Free (after initial investment)Free (after initial investment)

LimitlessLimitless

Solar Power ExamplesSolar Power Examples

Mt Everest is located in a very remote region Mt Everest is located in a very remote region between Nepal and Tibetbetween Nepal and Tibet

Scientists and climbers use solar power for Scientists and climbers use solar power for their communications equipment and light.their communications equipment and light.

Zapping ElectronsZapping Electrons

Electrons are located around the atom in Electrons are located around the atom in different different energy levelsenergy levels

When a photon hits an atom, it can When a photon hits an atom, it can bounce off (reflect) or be absorbedbounce off (reflect) or be absorbed

If the photon has just the right amount of If the photon has just the right amount of energy, it can make the electron “jump” to energy, it can make the electron “jump” to a higher energy levela higher energy level

Zapping ElectronsZapping Electrons

In some materials, the In some materials, the electrons might jump electrons might jump completely away from completely away from the rest of the atom, the rest of the atom, and might join other and might join other electrons to cause a electrons to cause a flow of charge that we flow of charge that we call electricitycall electricity

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Nanotechnology and Solar CellsNanotechnology and Solar Cells

Nanotechnology is the use or manipulation of Nanotechnology is the use or manipulation of very small particles or objectsvery small particles or objects

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Nanotechnology in Solar CellsNanotechnology in Solar Cells

Nanotechnology lets manufacturers add thinner Nanotechnology lets manufacturers add thinner layers of active materialslayers of active materials

Thinner layers let more light hit the active Thinner layers let more light hit the active materialsmaterials

Thinner layers allow more than one kind of active Thinner layers allow more than one kind of active material to be used, allowing different wavelengths material to be used, allowing different wavelengths of light to be absorbedof light to be absorbed

Nanotechnology in Solar CellsNanotechnology in Solar Cells

Nanoparticles allow electrons to move through Nanoparticles allow electrons to move through layers more easliylayers more easliy

When electrons move more easily, the cell is more When electrons move more easily, the cell is more efficientefficient

The Future is Bright!The Future is Bright!

Depends on research in nanotechnologyDepends on research in nanotechnology

Efficiency will continue to riseEfficiency will continue to rise

Cost will dropCost will drop

More of our nation’s power needs will be More of our nation’s power needs will be met by photovoltaic solar energymet by photovoltaic solar energy