Windmill energy

PRESENTED BY:PROF. S.V.ANGADI,

DEPARTMENT OF PHYSICS K L E’S

J T COLLEGE,GADAG

Renewable Energy or non Conventional energy :

Renewable energy is energy which is generated from natural sources i.e. sun, wind, rain, tides and can be generated again and again as and when required. They are available in plenty and by far most the cleanest sources of energy available on this planet. For eg: Energy that we receive from the sun can be used to generate electricity. Similarly, energy from wind, geothermal, biomass from plants, tides can be used this form of energy to another form.

Non-Renewable Energy or Conventional energy :

• A nonrenewable resource is a natural resource that cannot be re-made or re-grown at a scale comparable to its consumption.

• Non-Renewable energy is energy which is taken from the sources that are available on the earth in limited quantity and will vanish fifty-sixty years from now.

• Non-renewable sources are not environmental friendly and can have serious affect on our health.

• They are called non-renewable because they cannot be re-generated within a short span of time. Non-renewable sources exist in the form of fossil fuels, natural gas, oil and coal.

Merits of renewable energy over non renewable energy sources: RE OVER NRE

• The sun, wind, geothermal, ocean energy are available in the abundant quantity and free to use.

• • The non-renewable sources of energy that we are using are

limited and are bound to expire one day.

• Renewable sources have low carbon emissions, therefore they are considered as green and environment friendly.

• Non renewable sources emits hazardous chemicals and gases for the mankind

Conventional energy sources are: (a) Fossil fuel energy (b) Hydraulic energy (c) Nuclear energy

RENEWABLE RESOURCES

Renewable resources are natural resources that can be replenished in a short period of time.

● Solar

● Geothermal

● Wind

● Biomass

● Water

Non-Conventional Energy Sources The sources of energy which are being

produced continuously in nature and are in exhaustible are called renewable sources of energy (or) non-conventional energy.

Some of these sources are: (a) Wind energy (b) Tidal energy (c) Solar energy

Wind energy Winds are caused because of two factors. 1. The absorption of solar energy on the earth’s

surface and in the atmosphere. 2. The rotation of the earth about its axis and its

motion around the Sun. A wind mill converts the kinetic energy of

moving air into Mechanical energy that can be either used directly to run the Machine or to run the generator to produce electricity.

Wind Energy

History of Wind Power

Wind power evolved from the use of simple, light devices driven by aerodynamic forces to heavier drag devices and finally to light, more efficient lifts.

The sailboat is the earliest known use of wind power.

The first windmills were made to automate the tasks of grain grinding and water pumping in Persia 500-900AD

History of Wind as Electricity

The first use of a windmill to generate electricity was in Cleveland, Ohio in 1888 by Charles F. Brush.

In 1891, Dane Poul la Cour made the first aerodynamically (low solidity, four bladed) designed system.

By 1920, the la Cour system replaced all previous sail and fan systems.

Development of Wind Technology

-During the 1920’s modified propellers were used to drive direct current generators.

-Bulk Power Wind Energy was first made in Russia in 1931 (100kw Balaclava Wind Generator).

-The largest bulk wind energy producer was the Smith-Putnam Machine (Installed in Vermont, 1941)

European and American Involvement

After WWII European Countries developed wind systems further when fossil fuel shortages led to high energy costs.

US wind involvement began after the 1973 oil embargo. Beginning of the US Federal Wind Energy Program.

Where Does the Wind Come From?

The wind is a by-product of solar energy. Approximately 2% of the sun's energy reaching the earth is converted into wind energy. The surface of the earth heats and cools unevenly (differential heating), creating atmospheric pressure zones that make air flow from high- to low-pressure areas.

Wind power is a measure of the energy available in the wind. It is a function of the cube (third power) of the wind speed. If the wind speed is doubled, power in the wind increases by a factor of eight . This relationship means that small differences in wind speed lead to large differences in power.

Equation Of Wind Power

The amount of power available in the wind is determined by the equation:

w = 1/2 r A v3 Where w is power, r is air density, A is the

rotor area, and v is the wind speed. This equation states that the power is equal to one-half, times the air density, times the rotor area, times the cube of the wind speed. Air density varies according to elevation, temperature and weather fronts.

Classification of wind turbines on axis of rotation:

Horizontal axis wind turbine

Vertical axis wind turbine

Vertical Axis Turbines

Although vertical axis wind turbines have existed for centuries, they are not as common as their horizontal counterparts. The main reason for this is that they do not take advantage of the higher wind speeds at higher elevations above the ground as well as horizontal axis turbines.

Horizontal Axis Turbine This is the most common

wind turbine design. In addition to being parallel to the ground, the axis of blade rotation is parallel to the wind flow. Some machines are designed to operate in an upwind mode, with the blades upwind of the tower. In this case, a tail vane is usually used to keep the blades facing into the wind. Other designs operate in a downwind mode so that the wind passes the tower before striking the blades.

How Wind Works( working principle of windturbine)

LIFT AND DRAG Wind turbines (not

windmills) use LIFT LIFT devices work like

airplane wings This is why modern

wind turbines have 3 blades

Wind Flow Over an Air Foil Generates LIFT

Generator- The generator is what converts the turning motion of a wind turbine's blades into electricity. Inside this component, coils of wire are rotated in a magnetic field to produce electricity. Different generator designs produce either alternating current (AC) or direct current (DC), and they are available in a large range of output power ratings. The generator's rating, or size, is dependent on the length of the wind turbine's blades because more energy is captured by longer blades.

Controller- Turns the blades on at 8-16 mph and shuts them down around 65 to prevent any high wind damage.

Tower- Tall tubular metal shaft. The taller the tower, the more power produced.

Pros of Wind Power

Wind power Units are quickly constructed.

Wind generators are much smaller in size compared other types electrical generators.

Small size allows wind power to be very versatile.

ADVANTAGES OF WIND ENERGY

Wind power is a great compliment to a house with a preexisting photovoltaic system.

Serves as a great backup system. Wind power gives off no harmful

emissions into the environment.

It is a renewable resource.

The more time spent researching makes each new wind turbine more efficient.

Mass production of wind turbines drives down costs.

Downfalls To Wind Energy

Aesthetics – “Not in my back yard.” Inefficient and unreliable Hazard to bird migration

Aesthetics

Turbines are around 50ft high and can be seen for miles

Wind Farms use up more space than any other form of power plant

Access roads will follow the construction of a wind farm

Houses too close to turbines will be disturbed by their noise

“Not In My Back Yard”

                             

                                                

Inefficient & Unreliable

It is not uncommon for turbines to be hit by lightning strikes. This can cause damage to the turbine, and also provoke forest fires.

Propellers often fall off and are not repaired – example -> Altamont area of California

Inefficient: 9,369 turbines only produce 1.7 % of Germany’s power

No Wind = No Power

Hazard To Bird Migration Turbines and power lines

and a danger to migrating birds

Proof: - Wind Power Monthly

stated that large numbers of several bird species protected by European Law have been killed by turbines (1994)

- 200-300 Red Tail Hawks, 40-60 Golden Eagles are killed each year by turbines

- English nature stated that habitat loss, significant death to birds, and changes in migratory patterns are a result of wind farms

Pros of the Project

•Replaces 113 million tons of oil per year

• “Zero-emissions”

•Boost to Cape Cod’s economy

-600-1,000 new jobs for Cape Codders

•Does not require land

•May help with navigation and rescue

Cons of the Project

•Private companies take over of public/private land

•May alter public use and access

•Decrease in property values

•No regulatory process to govern project

•Potential hazard to wildlife

                                     

                                        

Thank you