Energy ResourcesA natural resource that can be

converted by humans into forms of energy in order to do useful

work!

Renewable Resources

Solar Energy

Solar Energy: The Ultimate Renewable

Resource

• Energy produced by the sun

• Clean, renewable source of energy

• Harnessed by solar collection methods such as solar cells

• Converted into usable energy such as electricity

• Originates with the thermonuclear fusion reactions occurring in the sun

What is Solar Energy?

.

Advantages: All chemical and

radioactive polluting byproducts of the thermonuclear reactions remain behind on the sun, while only pure radiant energy reaches the Earth.

Energy reaching the earth is incredible. By one calculation, 30 days of sunshine striking the Earth have the energy equivalent of the total of all the planet’s fossil fuels, both used and unused!

Advantages and DisadvantagesDisadvantage: Sun does not shine

consistently. Solar energy is a diffuse

source. To harness it, we must concentrate it into an amount and form that we can use, such as heat and electricity.

Addressed by approaching the problem through:

1) collection, 2) conversion, 3) storage.

Solar Energy

Using Solar Energy to Provide Heat collector

Passive solar heating Passive solar heating

Active solar heating Active solar heating

Solar energy collectors

• passive (no moving parts) and active (pumps).

• In both, a flat-plate collector is used to absorb the sun’s energy to heat the water.

• Passive method used sand and rocks and bricks

• Active methodd used water or air as medium

Photovoltaic Solar Cells

Photovoltaic Solar Cells• The potential

difference produced by single PV cell of 4 cm2 Size is about 0.4-0.5 volts and produced 60 mille amperes of current.

Because they work best under direct sunlight, parabolic dishes and troughs must be steered throughout the day in the direction of the sun.

Parabolic Dishes and Troughs

Direct Conversion into Electricity• Photovoltaic cells are

capable of directly converting sunlight into electricity.

• A simple wafer of silicon with wires attached to the layers. Current is produced based on types of silicon (n- and p-types) used for the layers. Each cell=0.5 volts.

• Battery needed as storage• No moving partsdo no

wear out, but because they are exposed to the weather, their lifespan is about 20 years.

Solar cookers

Solar cookerSolar cooker is work through reflect light with mirror.Concave or parabolic reflectors works more efficiencySolar cooker food have more nutrients due to slow heating

Solar water Heater Solar Furnace

Power Towers

Power tower in Barstow, California.

Renewable Resources

Wind - electricity No Greenhouse Gas Emissions

Insurance Against Conventional Fossil-based Price Risk No Sulfur Dioxide (SO2),

Nitrous Oxide (NOx), or Mercury Emissions

Why Wind Energy?Wind, for now, is the renewable energy resource/technology of choice

“Free” resource

A “clean” resource due to: Replacement of a “dirty” energy source

(coal) and, No emissions associated with its use

Can be utilized on underutilized land or on lands currently in commodity crop production (“harvest” on the surface and “harvest” above the surface)

Energy Production and the Environment

Energy use in power plants accounts for:

67% of air emissions of SO2, the primary cause of acid rain. SO2 causes acidification of lakes and damages forests and other habitats.

25% of NOx, which causes smog and respiratory ailments.

33% of Hg (mercury), a persistent, bio-accumulative toxin which increases in concentration as it moves up the food chain, e.g. from fish to birds, causing serious deformities and nerve disorders.

SOURCES: Union of Concerned Scientists (UCS)

Wind Energy Benefits

No air emissions

No fuel to mine, transport,

or store

No cooling water

No water pollution

No wastes

Wind Resources in the United States

Wind resources are characterized by wind-power density classes, ranging from class 1 (the lowest) to class 7 (the highest).

Good wind resources (class 3 and above) which have an average annual wind speed of at least 13 miles per hour, are found along the east coast, the Appalachian Mountain chain, the Great Plains, the Pacific Northwest, and some other locations.

Kansas Wind Potential

Kansas is one of the three best wind states in the country

Total “windy” land equals more than 108,000 square kilometers (about 1/2 of state)

Total Energy Potential = 1.07 trillion kWh or 121,900 MWa

Most of that potential probably won’t be developed . . .

Wind Turbines

Turbines: Different Sizes and Applications

Small (10 kW)• Homes (Grid-connected)• Farms• Remote Applications

(e.g. battery changing, water pumping, telecom sites)

Intermediate

(10-500 kW)• Village Power• Hybrid Systems• Distributed Power

Large (500 kW – 5 MW)

• Central Station Wind Farms

• Distributed Power• Offshore Wind

Wind Turbine Schematic

Wind - Natural Gas Comparison

WindLow Operating CostHigh Capital CostNon-dispatchableNo Fuel Supply/Cost

RiskNo Emissions

Natural Gas

High Operating Costs

Low Capital Cost

Dispatchable

Fuel Supply/Cost Risk

Smog, Greenhouse Gas Emissions

Wind Power Isn’t Perfect

Wind Power output varies over time; it isn’t dispatchable

Wind Power is location-dependent (rural vs. urban where it is needed most)

Wind Power is transmission-dependent for tie-in to the grid

Wind Power has environmental impacts

Wind Power can only meet part of the electrical load

Common Misunderstandings

Wind turbines are only generating electricity about one third of the time.

Wind turbines generate electricity essentially all the time, but only at their rated capacity about 30-40% of the time

Hydro powerWater flowing energy convert to electric energy

The minimum height of the waterfalls should be 10 m

The hydropower potential in India has 4x10 11 KW /hours. But we are utilize 11% in that only

Hydro power does not cause any pollution.

Tidal energyOcean tides produces by

gravitational forces of sun and moon

High tide enters the sea water into reservoir and rotate the turbine generate energy.

Low tides return the reservoir water into ocean and once again rotate the turbine

Only few sites are suitable for tidal energy in the world.

Ocean Thermal energy

The energy is available due to the difference in temperature of water at surface of the ocean and at deeper levels is called “ ocean thermal energy(OTE)”

The difference temperate required 20 degrees

The warm surface water of ocean is used to boil liquid ammonia and it passed with high pressure through the turbine.

Later cooled the gas ammonia with use of deeper water

The process continuously takes place.

Geo Thermal energy

The energy getting from the hot rocks Present inside of the earth is called “Geo Thermal Energy”

The heat comes from the fission of radio active naturally present in the rocks.

We can drill a hole up to rocks and get steam and pass through the turbine and generate electricity.

USA and New Zealand has several Geo thermal plants

Geothermal Energy

Dry steam Dry steam

Wet steam Wet steam

Hot water Hot water

Molten rock Molten rock

Hot dry-rock zones Hot dry-rock zones

Geothermal reservoirs Geothermal reservoirs

M.NagaPrasaRreddy.